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Sample records for type ia supernova

  1. ASTRONOMY AND ASTROPHYSICS Dark Energy, Type Ia supernovae, radiative

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    of Oklahoma Univ. of Oklahoma 79 ASTRONOMY AND ASTROPHYSICS Dark Energy, Type Ia supernovae, radiative transfer, Dark Energy, Type Ia supernovae, radiative transfer, The...

  2. Constraining Cosmic Evolution of Type Ia Supernovae (Journal...

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    Constraining Cosmic Evolution of Type Ia Supernovae Citation Details In-Document Search Title: Constraining Cosmic Evolution of Type Ia Supernovae We present the first large-scale...

  3. Defining photometric peculiar type Ia supernovae

    SciTech Connect (OSTI)

    González-Gaitán, S.; Pignata, G.; Förster, F.; Gutiérrez, C. P.; Bufano, F.; Galbany, L.; Hamuy, M.; De Jaeger, T.; Hsiao, E. Y.; Phillips, M. M.; Folatelli, G.; Anderson, J. P.

    2014-11-10

    We present a new photometric identification technique for SN 1991bg-like type Ia supernovae (SNe Ia), i.e., objects with light curve characteristics such as later primary maxima and the absence of a secondary peak in redder filters. This method is capable of selecting this sub-group from the normal type Ia population. Furthermore, we find that recently identified peculiar sub-types such as SNe Iax and super-Chandrasekhar SNe Ia have photometric characteristics similar to 91bg-like SNe Ia, namely, the absence of secondary maxima and shoulders at longer wavelengths, and can also be classified with our technique. The similarity of these different SN Ia sub-groups perhaps suggests common physical conditions. This typing methodology permits the photometric identification of peculiar SNe Ia in large upcoming wide-field surveys either to study them further or to obtain a pure sample of normal SNe Ia for cosmological studies.

  4. New approaches for modeling type Ia supernovae (Conference) ...

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    Type Ia supernovae (SNe Ia) are the largest thermonuclearexplosions in the Universe. Their light output can be seen across greatstances and has led to the discovery that the ...

  5. Ideal bandpasses for type Ia supernova cosmology

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    Davis, Tamara M.; Schmidt, Brian P.; Kim, Alex G.

    2005-10-24

    To use type Ia supernovae as standard candles for cosmologywe need accurate broadband magnitudes. In practice the observed magnitudemay differ from the ideal magnitude-redshift relationship either throughintrinsic inhomogeneities in the type Ia supernova population or throughobservational error. Here we investigate how we can choose filterbandpasses to reduce the error caused by both these effects. We find thatbandpasses with large integral fluxes and sloping wings are best able tominimise several sources of observational error, and are also leastsensitive to intrinsic differences in type Ia supernovae. The mostimportant feature of a complete filter set for type Ia supernovacosmology is that each bandpass be a redshifted copy of the first. Wedesign practical sets of redshifted bandpasses that are matched totypical high resistivity CCD and HgCdTe infra-red detector sensitivities.These are designed to minimise systematic error in well observedsupernovae, final designs for specific missions should also considersignal-to-noise requirements and observing strategy. In addition wecalculate how accurately filters need to be calibrated in order toachieve the required photometric accuracy of future supernova cosmologyexperiments such as the SuperNova-Acceleration-Probe (SNAP), which is onepossible realisation of the Joint Dark-Energy mission (JDEM). We considerthe effect of possible periodic miscalibrations that may arise from theconstruction of an interference filter.

  6. Type Ia Supernova Hubble Residuals and Host-Galaxy Properties...

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    SciTech Connect Search Results Journal Article: Type Ia Supernova Hubble Residuals and ... as distinguished from previous works that use magnitude corrections as a ...

  7. CEPHEID CALIBRATIONS OF MODERN TYPE Ia SUPERNOVAE: IMPLICATIONS...

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    CEPHEID CALIBRATIONS OF MODERN TYPE Ia SUPERNOVAE: IMPLICATIONS FOR THE HUBBLE CONSTANT ... Country of Publication: United States Language: English Subject: 79 ASTROPHYSICS, ...

  8. Improved Distances to Type Ia Supernovae withMulticolor Light...

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    We present an updated version of the Multicolor Light Curve Shape method to measure distances to type Ia supernovae (SN Ia), incorporating new procedures for K-correction and ...

  9. The Carnegie Supernova Project: Intrinsic colors of type Ia supernovae

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    Burns, Christopher R.; Persson, S. E.; Freedman, Wendy L.; Madore, Barry F. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Stritzinger, Maximilian; Contreras, Carlos [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Phillips, M. M.; Hsiao, E. Y.; Boldt, Luis; Campillay, Abdo; Castelln, Sergio; Morrell, Nidia; Salgado, Francisco [Carnegie Institution of Washington, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Folatelli, Gaston [Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, the University of Tokyo, 277-8583 Kashiwa (Japan); Suntzeff, Nicholas B. [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, Department of Physics and Astronomy, College Station, TX 77843 (United States)

    2014-07-01

    We present an updated analysis of the intrinsic colors of Type Ia supernova (SNe Ia) using the latest data release of the Carnegie Supernova Project. We introduce a new light-curve parameter very similar to stretch that is better suited for fast-declining events, and find that these peculiar types can be seen as extensions to the population of 'normal' SNe Ia. With a larger number of objects, an updated fit to the Lira relation is presented along with evidence for a dependence on the late-time slope of the B V light-curves with stretch and color. Using the full wavelength range from u to H band, we place constraints on the reddening law for the sample as a whole and also for individual events/hosts based solely on the observed colors. The photometric data continue to favor low values of R{sub V} , though with large variations from event to event, indicating an intrinsic distribution. We confirm the findings of other groups that there appears to be a correlation between the derived reddening law, R{sub V} , and the color excess, E(B V), such that larger E(B V) tends to favor lower R{sub V} . The intrinsic u-band colors show a relatively large scatter that cannot be explained by variations in R{sub V} or by the Goobar power-law for circumstellar dust, but rather is correlated with spectroscopic features of the supernova and is therefore likely due to metallicity effects.

  10. Constraining Cosmic Evolution of Type Ia Supernovae

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    Foley, Ryan J.; Filippenko, Alexei V.; Aguilera, C.; Becker, A.C.; Blondin, S.; Challis, P.; Clocchiatti, A.; Covarrubias, R.; Davis, T.M.; Garnavich, P.M.; Jha, S.; Kirshner, R.P.; Krisciunas, K.; Leibundgut, B.; Li, W.; Matheson, T.; Miceli, A.; Miknaitis, G.; Pignata, G.; Rest, A.; Riess, A.G.; /UC, Berkeley, Astron. Dept. /Cerro-Tololo InterAmerican Obs. /Washington U., Seattle, Astron. Dept. /Harvard-Smithsonian Ctr. Astrophys. /Chile U., Catolica /Bohr Inst. /Notre Dame U. /KIPAC, Menlo Park /Texas A-M /European Southern Observ. /NOAO, Tucson /Fermilab /Chile U., Santiago /Harvard U., Phys. Dept. /Baltimore, Space Telescope Sci. /Johns Hopkins U. /Res. Sch. Astron. Astrophys., Weston Creek /Stockholm U. /Hawaii U. /Illinois U., Urbana, Astron. Dept.

    2008-02-13

    We present the first large-scale effort of creating composite spectra of high-redshift type Ia supernovae (SNe Ia) and comparing them to low-redshift counterparts. Through the ESSENCE project, we have obtained 107 spectra of 88 high-redshift SNe Ia with excellent light-curve information. In addition, we have obtained 397 spectra of low-redshift SNe through a multiple-decade effort at Lick and Keck Observatories, and we have used 45 ultraviolet spectra obtained by HST/IUE. The low-redshift spectra act as a control sample when comparing to the ESSENCE spectra. In all instances, the ESSENCE and Lick composite spectra appear very similar. The addition of galaxy light to the Lick composite spectra allows a nearly perfect match of the overall spectral-energy distribution with the ESSENCE composite spectra, indicating that the high-redshift SNe are more contaminated with host-galaxy light than their low-redshift counterparts. This is caused by observing objects at all redshifts with similar slit widths, which corresponds to different projected distances. After correcting for the galaxy-light contamination, subtle differences in the spectra remain. We have estimated the systematic errors when using current spectral templates for K-corrections to be {approx}0.02 mag. The variance in the composite spectra give an estimate of the intrinsic variance in low-redshift maximum-light SN spectra of {approx}3% in the optical and growing toward the ultraviolet. The difference between the maximum-light low and high-redshift spectra constrain SN evolution between our samples to be < 10% in the rest-frame optical.

  11. Search for surviving companions in type Ia supernova remnants

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    Pan, Kuo-Chuan; Ricker, Paul M.; Taam, Ronald E. E-mail: pmricker@illinois.edu E-mail: taam@asiaa.sinica.edu.tw

    2014-09-01

    The nature of the progenitor systems of type Ia supernovae (SNe Ia) is still unclear. One way to distinguish between the single-degenerate scenario and double-degenerate scenario for their progenitors is to search for the surviving companions (SCs). Using a technique that couples the results from multi-dimensional hydrodynamics simulations with calculations of the structure and evolution of main-sequence- (MS-) and helium-rich SCs, the color and magnitude of MS- and helium-rich SCs are predicted as functions of time. The SC candidates in Galactic type Ia supernova remnants (Ia SNR) and nearby extragalactic Ia SNRs are discussed. We find that the maximum detectable distance of MS SCs (helium-rich SCs) is 0.6-4 Mpc (0.4-16 Mpc), if the apparent magnitude limit is 27 in the absence of extinction, suggesting that the Large and Small Magellanic Clouds and the Andromeda Galaxy are excellent environments in which to search for SCs. However, only five Ia SNRs have been searched for SCs, showing little support for the standard channels in the singe-degenerate scenario. To better understand the progenitors of SNe Ia, we encourage the search for SCs in other nearby Ia SNRs.

  12. A STUDY OF CARBON FEATURES IN TYPE Ia SUPERNOVA SPECTRA (Journal...

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    A STUDY OF CARBON FEATURES IN TYPE Ia SUPERNOVA SPECTRA Citation Details In-Document Search Title: A STUDY OF CARBON FEATURES IN TYPE Ia SUPERNOVA SPECTRA One of the major ...

  13. Type Ia supernova rate studies from the SDSS-II Supernova Study

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    Dilday, Benjamin

    2008-08-01

    The author presents new measurements of the type Ia SN rate from the SDSS-II Supernova Survey. The SDSS-II Supernova Survey was carried out during the Fall months (Sept.-Nov.) of 2005-2007 and discovered ~ 500 spectroscopically confirmed SNe Ia with densely sampled (once every ~ 4 days), multi-color light curves. Additionally, the SDSS-II Supernova Survey has discovered several hundred SNe Ia candidates with well-measured light curves, but without spectroscopic confirmation of type. This total, achieved in 9 months of observing, represents ~ 15-20% of the total SNe Ia discovered worldwide since 1885. The author describes some technical details of the SN Survey observations and SN search algorithms that contributed to the extremely high-yield of discovered SNe and that are important as context for the SDSS-II Supernova Survey SN Ia rate measurements.

  14. Type Ia Supernovae Project at NERSC

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of star called a white dwarf. The majority of SN Ia explosions occur far away from our galaxy; yet, due to their enormous intrinsic brightness, outshining billions of stars, we can...

  15. THE ULTRAVIOLET BRIGHTEST TYPE Ia SUPERNOVA 2011de

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    Brown, Peter J., E-mail: pbrown@physics.tamu.edu [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, Department of Physics and Astronomy, 4242 TAMU, College Station, TX 77843 (United States)

    2014-11-20

    We present and discuss the ultraviolet (UV)/optical photometric light curves and absolute magnitudes of the TypeIa supernova (SN Ia) 2011de from the Swift Ultraviolet/Optical Telescope. We find it to be the UV brightest SN Ia yet observedmore than a factor of 10 brighter than normal SNe Ia in the mid-ultraviolet. We find that the UV/optical brightness and broad light curve evolution can be modeled with additional flux from the shock of the ejecta hitting a relatively large red giant companion separated by 6 10{sup 13} cm. However, the post-maximum behavior of other UV-bright SNe Ia can also be modeled in a similar manner, including objects with UV spectroscopy or pre-maximum photometry which is inconsistent with this model. This suggests that similar UV luminosities can be intrinsic or caused by other forms of shock interaction. The high velocities reported for SN 2011de make it distinct from the UV-bright ''super-Chandrasekhar'' SNe Ia and the NUV-blue group of normal SNe Ia. SN 2011de is an extreme example of the UV variations in SNe Ia.

  16. Next-Generation Petascale Simulations of Type Ia Supernovae | Argonne

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Leadership Computing Facility deflagration to detonation transition model Deflagration to detonation transition model. Min lOng, Dan van Rossum, Sean Couch, George Jordan, Brad Gallagher, Don Lamb, University of Chicago; Michael E. Papka, Argonne National Laboratory/University of Chicago Next-Generation Petascale Simulations of Type Ia Supernovae PI Name: Don Lamb PI Email: lamb@oddjob.uchicago.edu Institution: The University of Chicago Allocation Program: INCITE Allocation Hours at ALCF:

  17. DIVERSITY OF TYPE Ia SUPERNOVAE IMPRINTED IN CHEMICAL ABUNDANCES

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    Tsujimoto, Takuji [National Astronomical Observatory of Japan, Mitaka-shi, Tokyo 181-8588 (Japan); Shigeyama, Toshikazu, E-mail: taku.tsujimoto@nao.ac.jp [Research Center for the Early Universe, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2012-12-01

    A time delay of Type Ia supernova (SN Ia) explosions hinders the imprint of their nucleosynthesis on stellar abundances. However, some occasional cases give birth to stars that avoid enrichment of their chemical compositions by massive stars and thereby exhibit an SN-Ia-like elemental feature including a very low [Mg/Fe] ( Almost-Equal-To - 1). We highlight the elemental feature of Fe-group elements for two low-Mg/Fe objects detected in nearby galaxies, and propose the presence of a class of SNe Ia that yield the low abundance ratios of [Cr, Mn, Ni/Fe]. Our novel models of chemical evolution reveal that our proposed class of SNe Ia (slow SNe Ia) is associated with ones exploding on a long timescale after their stellar birth and give a significant impact on the chemical enrichment in the Large Magellanic Cloud (LMC). In the Galaxy, on the other hand, this effect is unseen due to the overwhelming enrichment by the major class of SNe Ia that explode promptly (prompt SNe Ia) and eject a large amount of Fe-group elements. This nicely explains the different [Cr, Mn, Ni/Fe] features between the two galaxies as well as the puzzling feature seen in the LMC stars exhibiting very low Ca but normal Mg abundances. Furthermore, the corresponding channel of slow SN Ia is exemplified by performing detailed nucleosynthesis calculations in the scheme of SNe Ia resulting from a 0.8 + 0.6 M{sub Sun} white dwarf merger.

  18. Type Ia Supernova Hubble Residuals and Host-Galaxy Properties (Journal

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    Article) | SciTech Connect Journal Article: Type Ia Supernova Hubble Residuals and Host-Galaxy Properties Citation Details In-Document Search Title: Type Ia Supernova Hubble Residuals and Host-Galaxy Properties Kim et al. (2013) [K13] introduced a new methodology for determining peak- brightness absolute magnitudes of type Ia supernovae from multi-band light curves. We examine the relation between their parameterization of light curves and Hubble residuals, based on photometry synthesized

  19. Type Ia Supernova Spectral Line Ratios as LuminosityIndicators

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    Bongard, Sebastien; Baron, E.; Smadja, G.; Branch, David; Hauschildt, Peter H.

    2005-12-07

    Type Ia supernovae have played a crucial role in thediscovery of the dark energy, via the measurement of their light curvesand the determination of the peak brightness via fitting templates to theobserved lightcurve shape. Two spectroscopic indicators are also known tobe well correlated with peak luminosity. Since the spectroscopicluminosity indicators are obtained directly from observed spectra, theywill have different systematic errors than do measurements usingphotometry. Additionally, these spectroscopic indicators may be usefulfor studies of effects of evolution or age of the SNe~;Ia progenitorpopulation. We present several new variants of such spectroscopicindicators which are easy to automate and which minimize the effects ofnoise. We show that these spectroscopic indicators can be measured byproposed JDEM missions such as snap and JEDI.

  20. On silicon group elements ejected by supernovae type IA

    SciTech Connect (OSTI)

    De, Soma; Timmes, F. X. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ (United States); Brown, Edward F. [Joint Institute for Nuclear Astrophysics, University of Notre Dame, IN 46556 (United States); Calder, Alan C. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY (United States); Townsley, Dean M. [Department of Physics and Astronomy, The University of Alabama, Tuscaloosa, AL (United States); Athanassiadou, Themis [Swiss National Supercomputing Centre, Via Trevano 131, 6900 Lugano (Switzerland); Chamulak, David A. [Physics Division, Argonne National Laboratory, Argonne, IL (United States); Hawley, Wendy [Laboratoire d'Astrophysique de Marseille, Marseille cedex 13 F-13388 (France); Jack, Dennis, E-mail: somad@asu.edu [Departamento de Astronoma, Universidad de Guanajuato, Apartado Postal 144, 36000 Guanajuato (Mexico)

    2014-06-01

    There is evidence that the peak brightness of a Type Ia supernova is affected by the electron fraction Y {sub e} at the time of the explosion. The electron fraction is set by the aboriginal composition of the white dwarf and the reactions that occur during the pre-explosive convective burning. To date, determining the makeup of the white dwarf progenitor has relied on indirect proxies, such as the average metallicity of the host stellar population. In this paper, we present analytical calculations supporting the idea that the electron fraction of the progenitor systematically influences the nucleosynthesis of silicon group ejecta in Type Ia supernovae. In particular, we suggest the abundances generated in quasi-nuclear statistical equilibrium are preserved during the subsequent freeze-out. This allows potential recovery of Y {sub e} at explosion from the abundances recovered from an observed spectra. We show that measurement of {sup 28}Si, {sup 32}S, {sup 40}Ca, and {sup 54}Fe abundances can be used to construct Y {sub e} in the silicon-rich regions of the supernovae. If these four abundances are determined exactly, they are sufficient to recover Y {sub e} to 6%. This is because these isotopes dominate the composition of silicon-rich material and iron-rich material in quasi-nuclear statistical equilibrium. Analytical analysis shows the {sup 28}Si abundance is insensitive to Y {sub e}, the {sup 32}S abundance has a nearly linear trend with Y {sub e}, and the {sup 40}Ca abundance has a nearly quadratic trend with Y {sub e}. We verify these trends with post-processing of one-dimensional models and show that these trends are reflected in the model's synthetic spectra.

  1. Signatures of a companion star in type Ia supernovae

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    Maeda, Keiichi; Kutsuna, Masamichi; Shigeyama, Toshikazu

    2014-10-10

    Although type Ia supernovae (SNe Ia) have been used as precise cosmological distance indicators, their progenitor systems remain unresolved. One of the key questions is whether there is a nondegenerate companion star at the time of a thermonuclear explosion of a white dwarf. In this paper, we investigate whether an interaction between the SN ejecta and the companion star may result in observable footprints around the maximum brightness and thereafter, by performing multidimensional radiation transfer simulations based on hydrodynamic simulations of the interaction. We find that such systems result in variations in various observational characteristics due to different viewing directions, and the predicted behaviors (redder and fainter for the companion direction) are the opposite of what were suggested by the previous study. The variations are generally modest and within observed scatters. However, the model predicts trends between some observables different from those observationally derived, so a large sample of SNe Ia with small calibration errors may be used to constrain the existence of such a companion star. The variations in different colors in optical band passes can be mimicked by external extinctions, so such an effect could be a source of scatter in the peak luminosity and derived distance. After the peak, hydrogen-rich materials expelled from the companion will manifest themselves in hydrogen lines, but Hα is extremely difficult to identify. Alternatively, we find that P{sub β} in postmaximum near-infrared spectra can potentially provide a powerful diagnostic.

  2. Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light

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    Curves (Journal Article) | SciTech Connect Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light Curves Citation Details In-Document Search Title: Improved Dark Energy Constraints From ~ 100 New CfA Supernova Type Ia Light Curves We combine the CfA3 supernovae Type Ia (SN Ia) sample with samples from the literature to calculate improved constraints on the dark energy equation of state parameter, w. The CfA3 sample is added to the Union set of Kowalski et al. to form the

  3. Low Mach Number Modeling of Type Ia Supernovae

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    Almgren, Ann S.; Bell, John B.; Rendleman, Charles A.; Zingale,Michael

    2005-08-05

    We introduce a low Mach number equation set for the large-scale numerical simulation of carbon-oxygen white dwarfs experiencing a thermonuclear deflagration. Since most of the interesting physics in a Type Ia supernova transpires at Mach numbers from 0.01 to 0.1, such an approach enables both a considerable increase in accuracy and savings in computer time compared with frequently used compressible codes. Our equation set is derived from the fully compressible equations using low Mach number asymptotics, but without any restriction on the size of perturbations in density or temperature. Comparisons with simulations that use the fully compressible equations validate the low Mach number model in regimes where both are applicable. Comparisons to simulations based on the more traditional an elastic approximation also demonstrate the agreement of these models in the regime for which the anelastic approximation is valid. For low Mach number flows with potentially finite amplitude variations in density and temperature, the low Mach number model overcomes the limitations of each of the more traditional models and can serve as the basis for an accurate and efficient simulation tool.

  4. Comparing the host galaxies of type Ia, type II, and type Ibc supernovae

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    Shao, X.; Liang, Y. C.; Chen, X. Y.; Zhong, G. H.; Deng, L. C.; Zhang, B.; Shi, W. B.; Zhou, L.; Dennefeld, M.; Hammer, F.; Flores, H. E-mail: ycliang@bao.ac.cn

    2014-08-10

    We compare the host galaxies of 902 supernovae (SNe), including SNe Ia, SNe II, and SNe Ibc, which are selected by cross-matching the Asiago Supernova Catalog with the Sloan Digital Sky Survey (SDSS) Data Release 7. We selected an additional 213 galaxies by requiring the light fraction of spectral observations to be >15%, which could represent well the global properties of the galaxies. Among these 213 galaxies, 135 appear on the Baldwin-Phillips-Terlevich diagram, which allows us to compare the hosts in terms of whether they are star-forming (SF) galaxies, active galactic nuclei (AGNs; including composites, LINERs, and Seyfert 2s) or absorption-line galaxies (Absorps; i.e., their related emission lines are weak or non-existent). The diagrams related to the parameters D{sub n}(4000), H?{sub A}, stellar masses, star formation rates (SFRs), and specific SFRs for the SNe hosts show that almost all SNe II and most of the SNe Ibc occur in SF galaxies, which have a wide range of stellar masses and low D{sub n}(4000). The SNe Ia hosts as SF galaxies following similar trends. A significant fraction of SNe Ia occurs in AGNs and absorption-line galaxies, which are massive and have high D{sub n}(4000). The stellar population analysis from spectral synthesis fitting shows that the hosts of SNe II have a younger stellar population than hosts of SNe Ia. These results are compared with those of the 689 comparison galaxies where the SDSS fiber captures less than 15% of the total light. These comparison galaxies appear biased toward higher 12+log(O/H) (?0.1 dex) at a given stellar mass. Therefore, we believe the aperture effect should be kept in mind when the properties of the hosts for different types of SNe are discussed.

  5. Type Ia Supernova Hubble Residuals and Host-Galaxy Properties...

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    Tao, C.; Thomas, R. C.; Weaver, B. A. 79 ASTRONOMY AND ASTROPHYSICS distance scale, supernovae: general distance scale, supernovae: general Kim et al. (2013) K13 introduced a...

  6. Spectroscopic Determination of the Low Redshift Type Ia Supernova Rate from the Sloan Digital Sky Survey

    SciTech Connect (OSTI)

    Krughoff, K. S.; Connolly, Andrew J.; Frieman, Joshua; SubbaRao, Mark; Kilper, Gary; Schneider, Donald P.

    2011-04-10

    Supernova rates are directly coupled to high mass stellar birth and evolution. As such, they are one of the few direct measures of the history of cosmic stellar evolution. In this paper we describe an probabilistic technique for identifying supernovae within spectroscopic samples of galaxies. We present a study of 52 type Ia supernovae ranging in age from -14 days to +40 days extracted from a parent sample of \\simeq 50,000 spectra from the SDSS DR5. We find a Supernova Rate (SNR) of 0.472^{+0.048}_{-0.039}(Systematic)^{+0.081}_{-0.071}(Statistical)SNu at a redshift of = 0.1. This value is higher than other values at low redshift at the 1{\\sigma}, but is consistent at the 3{\\sigma} level. The 52 supernova candidates used in this study comprise the third largest sample of supernovae used in a type Ia rate determination to date. In this paper we demonstrate the potential for the described approach for detecting supernovae in future spectroscopic surveys.

  7. HUBBLE RESIDUALS OF NEARBY TYPE Ia SUPERNOVAE ARE CORRELATED...

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    ... MASS; RED SHIFT; SUPERNOVAE BINARY STARS; ERUPTIVE VARIABLE STARS; OPTICAL PROPERTIES; PHYSICAL PROPERTIES; STARS; VARIABLE STARS Word Cloud More Like This Full Text Journal ...

  8. Turbulence-Flame Interactions in Type Ia Supernovae (Journal...

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    turbulent intensity and l is the integral scale. For the larger integral scales characteristic of a real supernova, the flame structure is predicted to become complex and unsteady. ...

  9. Grouping normal type Ia supernovae by UV to optical color differences

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    Milne, Peter A.; Brown, Peter J.; Roming, Peter W. A.; Bufano, Filomena; Gehrels, Neil

    2013-12-10

    Observations of many Type Ia supernovae (SNe Ia) for multiple epochs per object with the Swift Ultraviolet Optical Telescope instrument have revealed that there exists order to the differences in the UV-optical colors of optically normal supernovae (SNe). We examine UV-optical color curves for 23 SNe Ia, dividing the SNe into four groups, and find that roughly one-third of 'NUV-blue' SNe Ia have bluer UV-optical colors than the larger 'NUV-red' group. Two minor groups are recognized, 'MUV-blue' and 'irregular' SNe Ia. While we conclude that the latter group is a subset of the NUV-red group, containing the SNe with the broadest optical peaks, we conclude that the 'MUV-blue' group is a distinct group. Separating into the groups and accounting for the time evolution of the UV-optical colors lowers the scatter in two NUV-optical colors (e.g., u v and uvw1 v) to the level of the scatter in b v. This finding is promising for extending the cosmological utilization of SNe Ia into the NUV. We generate spectrophotometry of 33 SNe Ia and determine the correct grouping for each. We argue that there is a fundamental spectral difference in the 2900-3500 wavelength range, a region suggested to be dominated by absorption from iron-peak elements. The NUV-blue SNe Ia feature less absorption than the NUV-red SNe Ia. We show that all NUV-blue SNe Ia in this sample also show evidence of unburned carbon in optical spectra, whereas only one NUV-red SN Ia features that absorption line. Every NUV-blue event also exhibits a low gradient of the Si II ?6355 absorption feature. Many NUV-red events also exhibit a low gradient, perhaps suggestive that NUV-blue events are a subset of the larger low-velocity gradient group.

  10. THE HYBRID CONe WD + He STAR SCENARIO FOR THE PROGENITORS OF TYPE Ia SUPERNOVAE

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    Wang, B.; Meng, X.; Liu, D.-D.; Han, Z.; Liu, Z.-W.

    2014-10-20

    Hybrid CONe white dwarfs (WDs) have been suggested to be possible progenitors of type Ia supernovae (SNe Ia). In this Letter, we systematically studied the hybrid CONe WD + He star scenario for the progenitors of SNe Ia, in which a hybrid CONe WD increases its mass to the Chandrasekhar mass limit by accreting He-rich material from a non-degenerate He star. We obtained the SN Ia birthrates and delay times for this scenario using to a series of detailed binary population synthesis simulations. The SN Ia birthrates for this scenario are ∼0.033-0.539 × 10{sup –3} yr{sup –1}, which roughly accounts for 1%-18% of all SNe Ia. The estimated delay times are ∼28 Myr-178 Myr, which makes these the youngest SNe Ia predicted by any progenitor model so far. We suggest that SNe Ia from this scenario may provide an alternative explanation for type Iax SNe. We also presented some properties of the donors at the point when the WDs reach the Chandrasekhar mass. These properties may be a good starting point for investigating the surviving companions of SNe Ia and for constraining the progenitor scenario studied in this work.

  11. Type Ia Supernova Hubble Residuals and Host-Galaxy Properties...

    Office of Scientific and Technical Information (OSTI)

    The K13 Hubble residual step with host mass is 0.013 ? 0.031 mag for a supernova subsample with data coverage corresponding to the K13 training; at ? 1?, the step is not ...

  12. CfA3: 185 TYPE Ia SUPERNOVA LIGHT CURVES FROM THE CfA

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    Hicken, Malcolm; Challis, Peter; Kirshner, Robert P.; Bakos, Gaspar; Berlind, Perry; Brown, Warren R.; Caldwell, Nelson; Calkins, Mike; Cho, Richard; Contreras, Maria; Jha, Saurabh; Matheson, Tom; Modjaz, Maryam; Rest, Armin; Michael Wood-Vasey, W.; Barton, Elizabeth J.; Bragg, Ann; Briceno, Cesar; Ciupik, Larry; Dendy, Kristi-Concannon E-mail: kirshner@cfa.harvard.edu

    2009-07-20

    We present multiband photometry of 185 type-Ia supernovae (SNe Ia), with over 11,500 observations. These were acquired between 2001 and 2008 at the F. L. Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics (CfA). This sample contains the largest number of homogeneously observed and reduced nearby SNe Ia (z {approx}< 0.08) published to date. It more than doubles the nearby sample, bringing SN Ia cosmology to the point where systematic uncertainties dominate. Our natural system photometry has a precision of {approx}<0.02 mag in BVRIr'i' and {approx}<0.04 mag in U for points brighter than 17.5 mag. We also estimate a systematic uncertainty of 0.03 mag in our SN Ia standard system BVRIr'i' photometry and 0.07 mag for U. Comparisons of our standard system photometry with published SN Ia light curves and comparison stars, where available for the same SN, reveal agreement at the level of a few hundredths mag in most cases. We find that 1991bg-like SNe Ia are sufficiently distinct from other SNe Ia in their color and light-curve-shape/luminosity relation that they should be treated separately in light-curve/distance fitter training samples. The CfA3 sample will contribute to the development of better light-curve/distance fitters, particularly in the few dozen cases where near-infrared photometry has been obtained and, together, can help disentangle host-galaxy reddening from intrinsic supernova color, reducing the systematic uncertainty in SN Ia distances due to dust.

  13. Nearby Supernova Factory Observations of SN 2005gj: Another TypeIa Supernova in a Massive Circumstellar Envelope

    SciTech Connect (OSTI)

    Aldering, G.; Antilogus, P.; Bailey, S.; Baltay, C.; Bauer, A.; Blanc, N.; Bongard, S.; Copin, Y.; Gangler, E.; Gilles, S.; Kessler, R.; Kocevski, D.; Lee, B.C.; Loken, S.; Nugent, P.; Pain, R.; Pecontal, E.; Pereira, R.; Perlmutter, S.; Rabinowitz, D.; Rigaudier, G.; Scalzo, R.; Smadja, G.; Thomas, R.C.; Wang, L.; Weaver, B.A.; Rabinowitz, D.; Bauer, A.

    2006-06-01

    We report the independent discovery and follow-up observations of supernova 2005gj by the Nearby Supernova Factory. This is the second confirmed case of a ''hybrid'' Type Ia/IIn supernova, which like the prototype SN 2002ic, we interpret as the explosion of a white dwarf interacting with a circumstellar medium. Our early-phase photometry of SN 2005gj shows that the strength of the interaction between the supernova ejecta and circumstellar material is much stronger than for SN 2002ic. Our .rst spectrum shows a hot continuum with broad and narrow H{alpha} emission. Later spectra, spanning over 4 months from outburst, show clear Type Ia features combined with broad and narrow H{gamma}, H{beta},H{alpha} and He I {lambda}{lambda}5876,7065 in emission. At higher resolution, P Cygni profiles are apparent. Surprisingly, we also observe an inverted P Cygni profile for [O III] {lambda}5007. We find that the lightcurve and measured velocity of the unshocked circumstellar material imply mass loss as recently as 8 years ago. This is in contrast to SN 2002ic, for which an inner cavity in the circumstellar material was inferred. Within the context of the thin-shell approximation, the early lightcurve is well-described by a flat radial density profile for the circumstellar material. However, our decomposition of the spectra into Type Ia and shock emission components allows for little obscuration of the supernova, suggesting an aspherical or clumpy distribution for the circumstellar material. We suggest that the emission line velocity profiles arise from electron scattering rather than the kinematics of the shock. This is supported by the inferred high densities, and the lack of evidence for evolution in the line widths. Ground- and space-based photometry, and Keck spectroscopy, of the host galaxy are used to ascertain that the host galaxy has low metallicity (Z/Z{sub {circle_dot}} < 0.3; 95% confidence) and that this galaxy is undergoing a significant star formation event that

  14. Cosmological parameter uncertainties from SALT-II type Ia supernova light curve models

    SciTech Connect (OSTI)

    Mosher, J.; Sako, M. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Guy, J.; Astier, P.; Betoule, M.; El-Hage, P.; Pain, R.; Regnault, N. [LPNHE, CNRS/IN2P3, Universit Pierre et Marie Curie Paris 6, Universi Denis Diderot Paris 7, 4 place Jussieu, F-75252 Paris Cedex 05 (France); Kessler, R.; Frieman, J. A. [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Marriner, J. [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Biswas, R.; Kuhlmann, S. [Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States); Schneider, D. P., E-mail: kessler@kicp.chicago.edu [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States)

    2014-09-20

    We use simulated type Ia supernova (SN Ia) samples, including both photometry and spectra, to perform the first direct validation of cosmology analysis using the SALT-II light curve model. This validation includes residuals from the light curve training process, systematic biases in SN Ia distance measurements, and a bias on the dark energy equation of state parameter w. Using the SN-analysis package SNANA, we simulate and analyze realistic samples corresponding to the data samples used in the SNLS3 analysis: ?120 low-redshift (z < 0.1) SNe Ia, ?255 Sloan Digital Sky Survey SNe Ia (z < 0.4), and ?290 SNLS SNe Ia (z ? 1). To probe systematic uncertainties in detail, we vary the input spectral model, the model of intrinsic scatter, and the smoothing (i.e., regularization) parameters used during the SALT-II model training. Using realistic intrinsic scatter models results in a slight bias in the ultraviolet portion of the trained SALT-II model, and w biases (w {sub input} w {sub recovered}) ranging from 0.005 0.012 to 0.024 0.010. These biases are indistinguishable from each other within the uncertainty; the average bias on w is 0.014 0.007.

  15. TYPE Ia SUPERNOVA COLORS AND EJECTA VELOCITIES: HIERARCHICAL BAYESIAN REGRESSION WITH NON-GAUSSIAN DISTRIBUTIONS

    SciTech Connect (OSTI)

    Mandel, Kaisey S.; Kirshner, Robert P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Foley, Ryan J., E-mail: kmandel@cfa.harvard.edu [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States)

    2014-12-20

    We investigate the statistical dependence of the peak intrinsic colors of Type Ia supernovae (SNe Ia) on their expansion velocities at maximum light, measured from the Si II ?6355 spectral feature. We construct a new hierarchical Bayesian regression model, accounting for the random effects of intrinsic scatter, measurement error, and reddening by host galaxy dust, and implement a Gibbs sampler and deviance information criteria to estimate the correlation. The method is applied to the apparent colors from BVRI light curves and Si II velocity data for 79 nearby SNe Ia. The apparent color distributions of high-velocity (HV) and normal velocity (NV) supernovae exhibit significant discrepancies for B V and B R, but not other colors. Hence, they are likely due to intrinsic color differences originating in the B band, rather than dust reddening. The mean intrinsic B V and B R color differences between HV and NV groups are 0.06 0.02 and 0.09 0.02 mag, respectively. A linear model finds significant slopes of 0.021 0.006 and 0.030 0.009 mag (10{sup 3} km s{sup 1}){sup 1} for intrinsic B V and B R colors versus velocity, respectively. Because the ejecta velocity distribution is skewed toward high velocities, these effects imply non-Gaussian intrinsic color distributions with skewness up to +0.3. Accounting for the intrinsic-color-velocity correlation results in corrections to A{sub V} extinction estimates as large as 0.12 mag for HV SNe Ia and +0.06 mag for NV events. Velocity measurements from SN Ia spectra have the potential to diminish systematic errors from the confounding of intrinsic colors and dust reddening affecting supernova distances.

  16. New approaches for modeling type Ia supernovae (Conference) ...

    Office of Scientific and Technical Information (OSTI)

    DOE Contract Number: DE-AC02-05CH11231 Resource Type: Conference Resource Relation: Conference: SciDAC 2006, Denver, CO, 25-29 June2006 Publisher: Institute of Physics, ...

  17. Type Ia supernovae from merging white dwarfs. II. Post-merger detonations

    SciTech Connect (OSTI)

    Raskin, Cody; Kasen, Daniel; Moll, Rainer; Woosley, Stan; Schwab, Josiah

    2014-06-10

    Merging carbon-oxygen (CO) white dwarfs are a promising progenitor system for Type Ia supernovae (SNe Ia), but the underlying physics and timing of the detonation are still debated. If an explosion occurs after the secondary star is fully disrupted, the exploding primary will expand into a dense CO medium that may still have a disk-like structure. This interaction will decelerate and distort the ejecta. Here we carry out multidimensional simulations of 'tamped' SN Ia models, using both particle and grid-based codes to study the merger and explosion dynamics and a radiative transfer code to calculate synthetic spectra and light curves. We find that post-merger explosions exhibit an hourglass-shaped asymmetry, leading to strong variations in the light curves with viewing angle. The two most important factors affecting the outcome are the scale height of the disk, which depends sensitively on the binary mass ratio, and the total {sup 56}Ni yield, which is governed by the central density of the remnant core. The synthetic broadband light curves rise and decline very slowly, and the spectra generally look peculiar, with weak features from intermediate mass elements but relatively strong carbon absorption. We also consider the effects of the viscous evolution of the remnant and show that a longer time delay between merger and explosion probably leads to larger {sup 56}Ni yields and more symmetrical remnants. We discuss the relevance of this class of aspherical 'tamped' SN Ia for explaining the class of 'super-Chandrasekhar' SN Ia.

  18. Near-infrared line identification in type Ia supernovae during the transitional phase

    SciTech Connect (OSTI)

    Friesen, Brian; Baron, E.; Wisniewski, John P.; Miller, Timothy R.; Parrent, Jerod T.; Thomas, R. C.; Marion, G. H.

    2014-09-10

    We present near-infrared synthetic spectra of a delayed-detonation hydrodynamical model and compare them to observed spectra of four normal Type Ia supernovae ranging from day +56.5 to day +85. This is the epoch during which supernovae are believed to be undergoing the transition from the photospheric phase, where spectra are characterized by line scattering above an optically thick photosphere, to the nebular phase, where spectra consist of optically thin emission from forbidden lines. We find that most spectral features in the near-infrared can be accounted for by permitted lines of Fe II and Co II. In addition, we find that [Ni II] fits the emission feature near 1.98 μm, suggesting that a substantial mass of {sup 58}Ni exists near the center of the ejecta in these objects, arising from nuclear burning at high density.

  19. Spectroscopic Properties of Star-Forming Host Galaxies and Type Ia Supernova Hubble Residuals in a Nearly Unbiased Sample

    SciTech Connect (OSTI)

    D'Andrea, Chris B.; et al.

    2011-12-20

    We examine the correlation between supernova host galaxy properties and their residuals on the Hubble diagram. We use supernovae discovered during the Sloan Digital Sky Survey II - Supernova Survey, and focus on objects at a redshift of z < 0.15, where the selection effects of the survey are known to yield a complete Type Ia supernova sample. To minimize the bias in our analysis with respect to measured host-galaxy properties, spectra were obtained for nearly all hosts, spanning a range in magnitude of -23 < M_r < -17. In contrast to previous works that use photometric estimates of host mass as a proxy for global metallicity, we analyze host-galaxy spectra to obtain gas-phase metallicities and star-formation rates from host galaxies with active star formation. From a final sample of ~ 40 emission-line galaxies, we find that light-curve corrected Type Ia supernovae are ~ 0.1 magnitudes brighter in high-metallicity hosts than in low-metallicity hosts. We also find a significant (> 3{\\sigma}) correlation between the Hubble residuals of Type Ia supernovae and the specific star-formation rate of the host galaxy. We comment on the importance of supernova/host-galaxy correlations as a source of systematic bias in future deep supernova surveys.

  20. Ultraviolet observations of Super-Chandrasekhar mass type Ia supernova candidates with swift UVOT

    SciTech Connect (OSTI)

    Brown, Peter J.; Smitka, Michael T.; Krisciunas, Kevin; Wang, Lifan; Kuin, Paul; De Pasquale, Massimiliano; Scalzo, Richard; Holland, Stephen; Milne, Peter

    2014-05-20

    Among Type Ia supernovae (SNe Ia), a class of overluminous objects exist whose ejecta mass is inferred to be larger than the canonical Chandrasekhar mass. We present and discuss the UV/optical photometric light curves, colors, absolute magnitudes, and spectra of three candidate Super-Chandrasekhar mass SNe—2009dc, 2011aa, and 2012dn—observed with the Swift Ultraviolet/Optical Telescope. The light curves are at the broad end for SNe Ia, with the light curves of SN 2011aa being among the broadest ever observed. We find all three to have very blue colors which may provide a means of excluding these overluminous SNe from cosmological analysis, though there is some overlap with the bluest of 'normal' SNe Ia. All three are overluminous in their UV absolute magnitudes compared to normal and broad SNe Ia, but SNe 2011aa and 2012dn are not optically overluminous compared to normal SNe Ia. The integrated luminosity curves of SNe 2011aa and 2012dn in the UVOT range (1600-6000 Å) are only half as bright as SN 2009dc, implying a smaller {sup 56}Ni yield. While it is not enough to strongly affect the bolometric flux, the early time mid-UV flux makes a significant contribution at early times. The strong spectral features in the mid-UV spectra of SNe 2009dc and 2012dn suggest a higher temperature and lower opacity to be the cause of the UV excess rather than a hot, smooth blackbody from shock interaction. Further work is needed to determine the ejecta and {sup 56}Ni masses of SNe 2011aa and 2012dn and to fully explain their high UV luminosities.

  1. THE EARLIEST NEAR-INFRARED TIME-SERIES SPECTROSCOPY OF A TYPE Ia SUPERNOVA

    SciTech Connect (OSTI)

    Hsiao, E. Y.; Phillips, M. M.; Morrell, N.; Contreras, C.; Roth, M.; Marion, G. H.; Kirshner, R. P.; Burns, C. R.; Freedman, W. L.; Persson, S. E.; Winge, C.; Gerardy, C. L.; Hoeflich, P.; Im, M.; Jeon, Y.; Pignata, G.; Stanishev, V.; and others

    2013-04-01

    We present ten medium-resolution, high signal-to-noise ratio near-infrared (NIR) spectra of SN 2011fe from SpeX on the NASA Infrared Telescope Facility (IRTF) and Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, obtained as part of the Carnegie Supernova Project. This data set constitutes the earliest time-series NIR spectroscopy of a Type Ia supernova (SN Ia), with the first spectrum obtained at 2.58 days past the explosion and covering -14.6 to +17.3 days relative to B-band maximum. C I {lambda}1.0693 {mu}m is detected in SN 2011fe with increasing strength up to maximum light. The delay in the onset of the NIR C I line demonstrates its potential to be an effective tracer of unprocessed material. For the first time in a SN Ia, the early rapid decline of the Mg II {lambda}1.0927 {mu}m velocity was observed, and the subsequent velocity is remarkably constant. The Mg II velocity during this constant phase locates the inner edge of carbon burning and probes the conditions under which the transition from deflagration to detonation occurs. We show that the Mg II velocity does not correlate with the optical light-curve decline rate {Delta}m{sub 15}(B). The prominent break at {approx}1.5 {mu}m is the main source of concern for NIR k-correction calculations. We demonstrate here that the feature has a uniform time evolution among SNe Ia, with the flux ratio across the break strongly correlated with {Delta}m{sub 15}(B). The predictability of the strength and the onset of this feature suggests that the associated k-correction uncertainties can be minimized with improved spectral templates.

  2. A Measurement of the Rate of Type Ia Supernovae in Galaxy Clusters from the SDSS-II Supernova Survey

    SciTech Connect (OSTI)

    Dilday, Benjamin; Bassett, Bruce; Becker, Andrew; Bender, Ralf; Castander, Francisco; Cinabro, David; Frieman, Joshua A.; Galbany, Lluis; Garnavich, Peter; Goobar, Ariel; Hopp, Ulrich; /Munich, Tech. U. /Munich U. Observ. /Tokyo U.

    2010-03-01

    We present measurements of the Type Ia supernova (SN) rate in galaxy clusters based on data from the Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey. The cluster SN Ia rate is determined from 9 SN events in a set of 71 C4 clusters at z {le} 0.17 and 27 SN events in 492 maxBCG clusters at 0.1 {le} z {le} 0.3. We find values for the cluster SN Ia rate of (0.37{sub -0.12-0.01}{sup +0.17+0.01}) SNur h{sup 2} and (0.55{sub -0.11-0.01}{sup +0.13+0.02}) SNur h{sup 2} (SNux = 10{sup -12}L{sub x{circle_dot}}{sup -1} yr{sup -1}) in C4 and maxBCG clusters, respectively, where the quoted errors are statistical and systematic, respectively. The SN rate for early-type galaxies is found to be (0.31{sub -0.12-0.01}{sup +0.18+0.01}) SNur h{sup 2} and (0.49{sub -0.11-0.01}{sup +0.15+0.02}) SNur h{sup 2} in C4 and maxBCG clusters, respectively. The SN rate for the brightest cluster galaxies (BCG) is found to be (2.04{sub -1.11-0.04}{sup +1.99+0.07}) SNur h{sup 2} and (0.36{sub -0.30-0.01}{sup +0.84+0.01}) SNur h{sup 2} in C4 and maxBCG clusters, respectively. The ratio of the SN Ia rate in cluster early-type galaxies to that of the SN Ia rate in field early-type galaxies is 1.94{sub -0.91-0.015}{sup +1.31+0.043} and 3.02{sub -1.03-0.048}{sup +1.31+0.062}, for C4 and maxBCG clusters, respectively. The SN rate in galaxy clusters as a function of redshift, which probes the late time SN Ia delay distribution, shows only weak dependence on redshift. Combining our current measurements with previous measurements, we fit the cluster SN Ia rate data to a linear function of redshift, and find r{sub L} = [(0.49{sub -0.14}{sup +0.15}) + (0.91{sub -0.81}{sup +0.85}) x z] SNuB h{sup 2}. A comparison of the radial distribution of SNe in cluster to field early-type galaxies shows possible evidence for an enhancement of the SN rate in the cores of cluster early-type galaxies. With an observation of at most 3 hostless, intra-cluster SNe Ia, we estimate the fraction of cluster SNe that are

  3. Toward Exascale Computing of Type Ia and Ib,c Supernovae: V&V of Current

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Models | Argonne Leadership Computing Facility Toward Exascale Computing of Type Ia and Ib,c Supernovae: V&V of Current Models PI Name: Don Lamb PI Email: lamb@oddjob.uchicago.edu Institution: University Of Chicago Allocation Program: INCITE Allocation Hours at ALCF: 40,000,000 Year: 2012 Research Domain: Physics This project continues a program of verification and validation of Type Ia supernova models. More 3-D simulations of the explosion phase will be performed, along with 2-D

  4. Strong near-infrared carbon in the Type Ia supernova iPTF13ebh

    SciTech Connect (OSTI)

    Hsiao, E. Y.; Burns, C. R.; Contreras, C.; Höflich, P.; Sand, D.; Marion, G. H.; Phillips, M. M.; Stritzinger, M.; González-Gaitán, S.; Mason, R. E.; Folatelli, G.; Parent, E.; Gall, C.; Amanullah, R.; Anupama, G. C.; Arcavi, I.; Banerjee, D. P. K.; Beletsky, Y.; Blanc, G. A.; Bloom, J. S.; Brown, P. J.; Campillay, A.; Cao, Y.; De Cia, A.; Diamond, T.; Freedman, W. L.; Gonzalez, C.; Goobar, A.; Holmbo, S.; Howell, D. A.; Johansson, J.; Kasliwal, M. M.; Kirshner, R. P.; Krisciunas, K.; Kulkarni, S. R.; Maguire, K.; Milne, P. A.; Morrell, N.; Nugent, P. E.; Ofek, E. O.; Osip, D.; Palunas, P.; Perley, D. A.; Persson, S. E.; Piro, A. L.; Rabus, M.; Roth, M.; Schiefelbein, J. M.; Srivastav, S.; Sullivan, M.; Suntzeff, N. B.; Surace, J.; Woźniak, P. R.; Yaron, O.

    2015-05-22

    We present near-infrared (NIR) time-series spectroscopy, as well as complementary ultraviolet (UV), optical, and NIR data, of the Type Ia supernova (SN Ia) iPTF13ebh, which was discovered within two days from the estimated time of explosion. The first NIR spectrum was taken merely 2.3 days after explosion and may be the earliest NIR spectrum yet obtained of a SN Ia. The most striking features in the spectrum are several NIR C I lines, and the C Iλ1.0693 μm line is the strongest ever observed in a SN Ia. Interestingly, no strong optical C II counterparts were found, even though the optical spectroscopic time series began early and is densely cadenced. Except at the very early epochs, within a few days from the time of explosion, we show that the strong NIR C I compared to the weaker optical C II appears to be general in SNe Ia. iPTF13ebh is a fast decliner with Δm15(B) = 1.79 ± 0.01, and its absolute magnitude obeys the linear part of the width-luminosity relation. It is therefore categorized as a “transitional” event, on the fast-declining end of normal SNe Ia as opposed to subluminous/91bg-like objects. iPTF13ebh shows NIR spectroscopic properties that are distinct from both the normal and subluminous/91bg-like classes, bridging the observed characteristics of the two classes. These NIR observations suggest that composition and density of the inner core are similar to that of 91bg-like events, and that it has a deep-reaching carbon burning layer that is not observed in more slowly declining SNe Ia. Furthermore, there is also a substantial difference between the explosion times inferred from the early-time light curve and the velocity evolution of the Si II λ0.6355 μm line, implying a long dark phase of ~4 days.

  5. Strong near-infrared carbon in the Type Ia supernova iPTF13ebh

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hsiao, E. Y.; Burns, C. R.; Contreras, C.; Höflich, P.; Sand, D.; Marion, G. H.; Phillips, M. M.; Stritzinger, M.; González-Gaitán, S.; Mason, R. E.; et al

    2015-05-22

    We present near-infrared (NIR) time-series spectroscopy, as well as complementary ultraviolet (UV), optical, and NIR data, of the Type Ia supernova (SN Ia) iPTF13ebh, which was discovered within two days from the estimated time of explosion. The first NIR spectrum was taken merely 2.3 days after explosion and may be the earliest NIR spectrum yet obtained of a SN Ia. The most striking features in the spectrum are several NIR C I lines, and the C Iλ1.0693 μm line is the strongest ever observed in a SN Ia. Interestingly, no strong optical C II counterparts were found, even though themore » optical spectroscopic time series began early and is densely cadenced. Except at the very early epochs, within a few days from the time of explosion, we show that the strong NIR C I compared to the weaker optical C II appears to be general in SNe Ia. iPTF13ebh is a fast decliner with Δm15(B) = 1.79 ± 0.01, and its absolute magnitude obeys the linear part of the width-luminosity relation. It is therefore categorized as a “transitional” event, on the fast-declining end of normal SNe Ia as opposed to subluminous/91bg-like objects. iPTF13ebh shows NIR spectroscopic properties that are distinct from both the normal and subluminous/91bg-like classes, bridging the observed characteristics of the two classes. These NIR observations suggest that composition and density of the inner core are similar to that of 91bg-like events, and that it has a deep-reaching carbon burning layer that is not observed in more slowly declining SNe Ia. Furthermore, there is also a substantial difference between the explosion times inferred from the early-time light curve and the velocity evolution of the Si II λ0.6355 μm line, implying a long dark phase of ~4 days.« less

  6. Strong near-infrared carbon in the Type Ia supernova iPTF13ebh

    SciTech Connect (OSTI)

    Hsiao, E. Y.; Burns, C. R.; Contreras, C.; Hflich, P.; Sand, D.; Marion, G. H.; Phillips, M. M.; Stritzinger, M.; Gonzlez-Gaitn, S.; Mason, R. E.; Folatelli, G.; Parent, E.; Gall, C.; Amanullah, R.; Anupama, G. C.; Arcavi, I.; Banerjee, D. P. K.; Beletsky, Y.; Blanc, G. A.; Bloom, J. S.; Brown, P. J.; Campillay, A.; Cao, Y.; De Cia, A.; Diamond, T.; Freedman, W. L.; Gonzalez, C.; Goobar, A.; Holmbo, S.; Howell, D. A.; Johansson, J.; Kasliwal, M. M.; Kirshner, R. P.; Krisciunas, K.; Kulkarni, S. R.; Maguire, K.; Milne, P. A.; Morrell, N.; Nugent, P. E.; Ofek, E. O.; Osip, D.; Palunas, P.; Perley, D. A.; Persson, S. E.; Piro, A. L.; Rabus, M.; Roth, M.; Schiefelbein, J. M.; Srivastav, S.; Sullivan, M.; Suntzeff, N. B.; Surace, J.; Wo?niak, P. R.; Yaron, O.

    2015-05-22

    We present near-infrared (NIR) time-series spectroscopy, as well as complementary ultraviolet (UV), optical, and NIR data, of the Type Ia supernova (SN Ia) iPTF13ebh, which was discovered within two days from the estimated time of explosion. The first NIR spectrum was taken merely 2.3 days after explosion and may be the earliest NIR spectrum yet obtained of a SN Ia. The most striking features in the spectrum are several NIR C I lines, and the C I?1.0693 ?m line is the strongest ever observed in a SN Ia. Interestingly, no strong optical C II counterparts were found, even though the optical spectroscopic time series began early and is densely cadenced. Except at the very early epochs, within a few days from the time of explosion, we show that the strong NIR C I compared to the weaker optical C II appears to be general in SNe Ia. iPTF13ebh is a fast decliner with ?m15(B) = 1.79 0.01, and its absolute magnitude obeys the linear part of the width-luminosity relation. It is therefore categorized as a transitional event, on the fast-declining end of normal SNe Ia as opposed to subluminous/91bg-like objects. iPTF13ebh shows NIR spectroscopic properties that are distinct from both the normal and subluminous/91bg-like classes, bridging the observed characteristics of the two classes. These NIR observations suggest that composition and density of the inner core are similar to that of 91bg-like events, and that it has a deep-reaching carbon burning layer that is not observed in more slowly declining SNe Ia. Furthermore, there is also a substantial difference between the explosion times inferred from the early-time light curve and the velocity evolution of the Si II ?0.6355 ?m line, implying a long dark phase of ~4 days.

  7. Measurements of the Rate of Type Ia Supernovae at Redshift z < ~0.3 from the SDSS-II Supernova Survey

    SciTech Connect (OSTI)

    Dilday, Benjamin; Smith, Mathew; Bassett, Bruce; Becker, Andrew; Bender, Ralf; Castander, Francisco; Cinabro, David; Filippenko, Alexei V.; Frieman, Joshua A.; Galbany, Lluis; Garnavich, Peter M.; /Notre Dame U. /Stockholm U., OKC /Stockholm U.

    2010-01-01

    We present a measurement of the volumetric Type Ia supernova (SN Ia) rate based on data from the Sloan Digital Sky Survey II (SDSS-II) Supernova Survey. The adopted sample of supernovae (SNe) includes 516 SNe Ia at redshift z {approx}< 0.3, of which 270 (52%) are spectroscopically identified as SNe Ia. The remaining 246 SNe Ia were identified through their light curves; 113 of these objects have spectroscopic redshifts from spectra of their host galaxy, and 133 have photometric redshifts estimated from the SN light curves. Based on consideration of 87 spectroscopically confirmed non-Ia SNe discovered by the SDSS-II SN Survey, we estimate that 2.04{sub -0.95}{sup +1.61}% of the photometric SNe Ia may be misidentified. The sample of SNe Ia used in this measurement represents an order of magnitude increase in the statistics for SN Ia rate measurements in the redshift range covered by the SDSS-II Supernova Survey. If we assume a SN Ia rate that is constant at low redshift (z < 0.15), then the SN observations can be used to infer a value of the SN rate of r{sub V} = (2.69{sub -0.30-0.01}{sup +0.34+0.21}) x 10{sup -5} SNe yr{sup -1} Mpc{sup -3} (H{sub 0}/(70 km s{sup -1} Mpc{sup -1})){sup 3} at a mean redshift of {approx} 0.12, based on 79 SNe Ia of which 72 are spectroscopically confirmed. However, the large sample of SNe Ia included in this study allows us to place constraints on the redshift dependence of the SN Ia rate based on the SDSS-II Supernova Survey data alone. Fitting a power-law model of the SN rate evolution, r{sub V} (z) = A{sub p} x ((1+z)/(1+z{sub 0})){sup {nu}}, over the redshift range 0.0 < z < 0.3 with z{sub 0} = 0.21, results in A{sub p} = (3.43{sub -0.15}{sup +0.15}) x 10{sup -5} SNe yr{sup -1} Mpc{sup -3} (H{sub 0}/(70 km s{sup -1} Mpc{sup -1})){sup 3} and {nu} = 2.04{sub -0.89}{sup +0.90}.

  8. Consistent use of type Ia supernovae highly magnified by galaxy clusters to constrain the cosmological parameters

    SciTech Connect (OSTI)

    Zitrin, Adi [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Redlich, Matthias [Universitt Heidelberg, Zentrum fr Astronomie, Institut fr Theoretische Astrophysik, Philosophenweg 12, D-69120 Heidelberg (Germany); Broadhurst, Tom, E-mail: adizitrin@gmail.com [Department of Theoretical Physics, University of Basque Country UPV/EHU, Bilbao (Spain)

    2014-07-01

    We discuss how Type Ia supernovae (SNe) strongly magnified by foreground galaxy clusters should be self-consistently treated when used in samples fitted for the cosmological parameters. While the cluster lens magnification of a SN can be well constrained from sets of multiple images of various background galaxies with measured redshifts, its value is typically dependent on the fiducial set of cosmological parameters used to construct the mass model. In such cases, one should not naively demagnify the observed SN luminosity by the model magnification into the expected Hubble diagram, which would create a bias, but instead take into account the cosmological parameters a priori chosen to construct the mass model. We quantify the effect and find that a systematic error of typically a few percent, up to a few dozen percent per magnified SN may be propagated onto a cosmological parameter fit unless the cosmology assumed for the mass model is taken into account (the bias can be even larger if the SN is lying very near the critical curves). We also simulate how such a bias propagates onto the cosmological parameter fit using the Union2.1 sample supplemented with strongly magnified SNe. The resulting bias on the deduced cosmological parameters is generally at the few percent level, if only few biased SNe are included, and increases with the number of lensed SNe and their redshift. Samples containing magnified Type Ia SNe, e.g., from ongoing cluster surveys, should readily account for this possible bias.

  9. A SUPER-EDDINGTON WIND SCENARIO FOR THE PROGENITORS OF TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Ma, Xin; Chen, Xuefei; Chen, Hai-liang; Han, Zhanwen; Denissenkov, Pavel A. E-mail: cxf@ynao.ac.cn

    2013-12-01

    The accretion of hydrogen-rich material on to carbon-oxygen white dwarfs (CO WDs) is crucial for understanding Type Ia supernova (SN Ia) from the single-degenerate model, but this process has not been well understood due to the numerical difficulties in treating H and He flashes during the accretion. For CO WD masses from 0.5 to 1.378 M {sub ?} and accretion rates in the range from 10{sup 8} to 10{sup 5} M {sub ?} yr{sup 1}, we simulated the accretion of solar-composition material on to CO WDs using the state-of-the-art stellar evolution code of MESA. For comparison with steady-state models, we first ignored the contribution from nuclear burning to the luminosity when determining the Eddington accretion rate, and found that the properties of H burning in our accreting CO WD models are similar to those from the steady-state models, except that the critical accretion rates at which the WDs turn into red giants or H-shell flashes occur on their surfaces are slightly higher than those from the steady-state models. However, the super-Eddington wind is triggered at much lower accretion rates than previously thought, when the contribution of nuclear burning to the total luminosity is included. This super-Eddington wind naturally prevents the CO WDs with high accretion rates from becoming red giants, thus presenting an alternative to the optically thick wind proposed by Hachisu etal. Furthermore, the super-Eddington wind works in low-metallicity environments, which may explain SNe Ia observed at high redshifts.

  10. Type Ia supernova rate measurements to redshift 2.5 from CANDELS: Searching for prompt explosions in the early universe

    SciTech Connect (OSTI)

    Rodney, Steven A.; Riess, Adam G.; Graur, Or; Jones, David O. [Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218 (United States); Strolger, Louis-Gregory; Dahlen, Tomas; Casertano, Stefano; Ferguson, Henry C.; Koekemoer, Anton M. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Dickinson, Mark E. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Garnavich, Peter [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Hayden, Brian [E.O. Lawrence Berkeley National Lab, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Jha, Saurabh W.; McCully, Curtis; Patel, Brandon [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); Kirshner, Robert P. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Mobasher, Bahram [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Weiner, Benjamin J. [Department of Astronomy, University of Arizona, Tucson, AZ 85721 (United States); Cenko, S. Bradley [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Clubb, Kelsey I. [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); and others

    2014-07-01

    The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) was a multi-cycle treasury program on the Hubble Space Telescope (HST) that surveyed a total area of ?0.25 deg{sup 2} with ?900 HST orbits spread across five fields over three years. Within these survey images we discovered 65 supernovae (SNe) of all types, out to z ? 2.5. We classify ?24 of these as Type Ia SNe (SNe Ia) based on host galaxy redshifts and SN photometry (supplemented by grism spectroscopy of six SNe). Here we present a measurement of the volumetric SN Ia rate as a function of redshift, reaching for the first time beyond z = 2 and putting new constraints on SN Ia progenitor models. Our highest redshift bin includes detections of SNe that exploded when the universe was only ?3 Gyr old and near the peak of the cosmic star formation history. This gives the CANDELS high redshift sample unique leverage for evaluating the fraction of SNe Ia that explode promptly after formation (<500 Myr). Combining the CANDELS rates with all available SN Ia rate measurements in the literature we find that this prompt SN Ia fraction is f{sub P} = 0.53{sub stat0.10}{sup 0.09}{sub sys0.26}{sup 0.10}, consistent with a delay time distribution that follows a simple t {sup 1} power law for all times t > 40 Myr. However, mild tension is apparent between ground-based low-z surveys and space-based high-z surveys. In both CANDELS and the sister HST program CLASH (Cluster Lensing And Supernova Survey with Hubble), we find a low rate of SNe Ia at z > 1. This could be a hint that prompt progenitors are in fact relatively rare, accounting for only 20% of all SN Ia explosionsthough further analysis and larger samples will be needed to examine that suggestion.

  11. A POSSIBLE EVOLUTIONARY SCENARIO OF HIGHLY MAGNETIZED SUPER-CHANDRASEKHAR WHITE DWARFS: PROGENITORS OF PECULIAR TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Das, Upasana; Mukhopadhyay, Banibrata; Rao, A. R. E-mail: bm@physics.iisc.ernet.in

    2013-04-10

    Several recently discovered peculiar Type Ia supernovae seem to demand an altogether new formation theory that might help explain the puzzling dissimilarities between them and the standard Type Ia supernovae. The most striking aspect of the observational analysis is the necessity of invoking super-Chandrasekhar white dwarfs having masses {approx}2.1-2.8 M{sub Sun }, M{sub Sun} being the mass of Sun, as their most probable progenitors. Strongly magnetized white dwarfs having super-Chandrasekhar masses have already been established as potential candidates for the progenitors of peculiar Type Ia supernovae. Owing to the Landau quantization of the underlying electron degenerate gas, theoretical results yielded the observationally inferred mass range. Here, we sketch a possible evolutionary scenario by which super-Chandrasekhar white dwarfs could be formed by accretion on to a commonly observed magnetized white dwarf, invoking the phenomenon of flux freezing. This opens multiple possible evolution scenarios ending in supernova explosions of super-Chandrasekhar white dwarfs having masses within the range stated above. We point out that our proposal has observational support, such as the recent discovery of a large number of magnetized white dwarfs by the Sloan Digital Sky Survey.

  12. The crossing statistic: dealing with unknown errors in the dispersion of Type Ia supernovae

    SciTech Connect (OSTI)

    Shafieloo, Arman; Clifton, Timothy; Ferreira, Pedro E-mail: tclifton@astro.ox.ac.uk

    2011-08-01

    We propose a new statistic that has been designed to be used in situations where the intrinsic dispersion of a data set is not well known: The Crossing Statistic. This statistic is in general less sensitive than χ{sup 2} to the intrinsic dispersion of the data, and hence allows us to make progress in distinguishing between different models using goodness of fit to the data even when the errors involved are poorly understood. The proposed statistic makes use of the shape and trends of a model's predictions in a quantifiable manner. It is applicable to a variety of circumstances, although we consider it to be especially well suited to the task of distinguishing between different cosmological models using type Ia supernovae. We show that this statistic can easily distinguish between different models in cases where the χ{sup 2} statistic fails. We also show that the last mode of the Crossing Statistic is identical to χ{sup 2}, so that it can be considered as a generalization of χ{sup 2}.

  13. FIRST EVIDENCE OF GLOBULAR CLUSTER FORMATION FROM THE EJECTA OF PROMPT TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Tsujimoto, Takuji [National Astronomical Observatory of Japan, Mitaka-shi, Tokyo 181-8588 (Japan); Bekki, Kenji, E-mail: taku.tsujimoto@nao.ac.jp [ICRAR, M468, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia)

    2012-06-01

    Recent spectroscopic observations of globular clusters (GCs) in the Large Magellanic Cloud (LMC) have discovered that one of the intermediate-age GCs, NGC 1718, with [Fe/H] = -0.7 has an extremely low [Mg/Fe] ratio of {approx}-0.9. We propose that NGC 1718 was formed from the ejecta of Type Ia supernovae mixed with very metal-poor ([Fe/H] <-1.3) gas about {approx}2 Gyr ago. The proposed scenario is shown to be consistent with the observed abundances of Fe-group elements such as Cr, Mn, and Ni. In addition, compelling evidence for asymptotic giant branch stars playing a role in chemical enrichment during this GC formation is found. We suggest that the origin of the metal-poor gas is closely associated with efficient gas transfer from the outer gas disk of the Small Magellanic Cloud to the LMC disk. We anticipate that the outer part of the LMC disk contains field stars exhibiting significantly low [Mg/Fe] ratios, formed through the same process as NGC 1718.

  14. Type Ia supernovae yielding distances with 3-4% precision (Journal...

    Office of Scientific and Technical Information (OSTI)

    A paper copy of this document is also available for sale to the public from the National Technical Information Service, Springfield, VA at www.ntis.gov. The luminosities of Type Ia ...

  15. THE DETONATION MECHANISM OF THE PULSATIONALLY ASSISTED GRAVITATIONALLY CONFINED DETONATION MODEL OF Type Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Jordan, G. C. IV; Graziani, C.; Weide, K.; Norris, J.; Hudson, R.; Lamb, D. Q.; Fisher, R. T.; Townsley, D. M.; Meakin, C.; Reid, L. B.

    2012-11-01

    We describe the detonation mechanism composing the 'pulsationally assisted' gravitationally confined detonation (GCD) model of Type Ia supernovae. This model is analogous to the previous GCD model reported in Jordan et al.; however, the chosen initial conditions produce a substantively different detonation mechanism, resulting from a larger energy release during the deflagration phase. The resulting final kinetic energy and {sup 56}Ni yields conform better to observational values than is the case for the 'classical' GCD models. In the present class of models, the ignition of a deflagration phase leads to a rising, burning plume of ash. The ash breaks out of the surface of the white dwarf, flows laterally around the star, and converges on the collision region at the antipodal point from where it broke out. The amount of energy released during the deflagration phase is enough to cause the star to rapidly expand, so that when the ash reaches the antipodal point, the surface density is too low to initiate a detonation. Instead, as the ash flows into the collision region (while mixing with surface fuel), the star reaches its maximally expanded state and then contracts. The stellar contraction acts to increase the density of the star, including the density in the collision region. This both raises the temperature and density of the fuel-ash mixture in the collision region and ultimately leads to thermodynamic conditions that are necessary for the Zel'dovich gradient mechanism to produce a detonation. We demonstrate feasibility of this scenario with three three-dimensional (3D), full star simulations of this model using the FLASH code. We characterized the simulations by the energy released during the deflagration phase, which ranged from 38% to 78% of the white dwarf's binding energy. We show that the necessary conditions for detonation are achieved in all three of the models.

  16. Persistent C II absorption in the normal type Ia supernova 2002fk

    SciTech Connect (OSTI)

    Cartier, Rgis; Zelaya, Paula [Millennium Institute of Astrophysics, Casilla 36-D, Santiago (Chile); Hamuy, Mario; Maza, Jos; Gonzlez, Luis; Huerta, Leonor [Departamento de Astronoma, Universidad de Chile, Casilla 36-D, Santiago (Chile); Pignata, Giuliano [Departamento Ciencias Fisicas, Universidad Andres Bello, Av. Repblica 252, Santiago (Chile); Frster, Francisco [Center for Mathematical Modelling, Universidad de Chile, Avenida Blanco Encalada 2120, Piso 7, Santiago (Chile); Folatelli, Gaston [Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Phillips, Mark M.; Morrell, Nidia; Contreras, Carlos; Roth, Miguel; Gonzlez, Sergio [Carnegie Institution of Washington, Las Campanas Observatory, Colina el Pino s/n, Casilla 601 (Chile); Krisciunas, Kevin; Suntzeff, Nicholas B. [Department of Physics and Astronomy, Texas A and M University, 4242 TAMU, College Station, TX 77843 (United States); Clocchiatti, Alejandro [Departamento de Astronoma y Astrofsica, Pontificia Universidad Catlica de Chile, Casilla 306, Santiago (Chile); Coppi, Paolo [Department of Astronomy, Yale University, New Haven, CT 06520-8101 (United States); Koviak, Kathleen, E-mail: rcartier@das.uchile.cl [Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 911901 (United States)

    2014-07-01

    We present well-sampled UBVRIJHK photometry of SN 2002fk starting 12 days before maximum light through 122 days after peak brightness, along with a series of 15 optical spectra from 4 to +95 days since maximum. Our observations show the presence of C II lines in the early-time spectra of SN 2002fk, expanding at 11,000 km s{sup 1} and persisting until 8 days past maximum light with a velocity of ?9000 km s{sup 1}. SN 2002fk is characterized by a small velocity gradient of v-dot {sub Si} {sub II}=26 km s{sup 1} day{sup 1}, possibly caused by an off-center explosion with the ignition region oriented toward the observer. The connection between the viewing angle of an off-center explosion and the presence of C II in the early-time spectrum suggests that the observation of C II could be also due to a viewing angle effect. Adopting the Cepheid distance to NGC 1309 we provide the first H {sub 0} value based on near-infrared (near-IR) measurements of a Type Ia supernova (SN) between 63.0 0.8 (3.4 systematic) and 66.7 1.0 (3.5 systematic) km s{sup 1} Mpc{sup 1}, depending on the absolute magnitude/decline rate relationship adopted. It appears that the near-IR yields somewhat lower (6%-9%) H {sub 0} values than the optical. It is essential to further examine this issue by (1) expanding the sample of high-quality near-IR light curves of SNe in the Hubble flow, and (2) increasing the number of nearby SNe with near-IR SN light curves and precise Cepheid distances, which affords the promise to deliver a more precise determination of H {sub 0}.

  17. EVOLUTION OF POST-IMPACT REMNANT HELIUM STARS IN TYPE Ia SUPERNOVA REMNANTS WITHIN THE SINGLE-DEGENERATE SCENARIO

    SciTech Connect (OSTI)

    Pan, Kuo-Chuan; Ricker, Paul M.; Taam, Ronald E. E-mail: pmricker@illinois.edu

    2013-08-10

    The progenitor systems of Type Ia supernovae (SNe Ia) are still under debate. Based on recent hydrodynamics simulations, non-degenerate companions in the single-degenerate scenario (SDS) should survive the supernova (SN) impact. One way to distinguish between the SDS and the double-degenerate scenario is to search for the post-impact remnant stars (PIRSs) in SN Ia remnants. Using a technique that combines multi-dimensional hydrodynamics simulations with one-dimensional stellar evolution simulations, we have examined the post-impact evolution of helium-rich binary companions in the SDS. It is found that these helium-rich PIRSs (He PIRSs) dramatically expand and evolve to a luminous phase (L {approx} 10{sup 4} L{sub Sun }) about 10 yr after an SN explosion. Subsequently, they contract and evolve to become hot blue-subdwarf-like (sdO-like) stars by releasing gravitational energy, persisting as sdO-like stars for several million years before evolving to the helium red-giant phase. We therefore predict that a luminous OB-like star should be detectable within {approx}30 yr after the SN explosion. Thereafter, it will shrink and become an sdO-like star in the central regions of SN Ia remnants within star-forming regions for SN Ia progenitors evolved via the helium-star channel in the SDS. These He PIRSs are predicted to be rapidly rotating (v{sub rot} {approx}> 50 km s{sup -1}) and to have high spatial velocities (v{sub linear} {approx}> 500 km s{sup -1}). Furthermore, if SN remnants have diffused away and are not recognizable at a later stage, He PIRSs could be an additional source of single sdO stars and/or hypervelocity stars.

  18. Constraints on the progenitor system of the type Ia supernova 2014J from pre-explosion Hubble space telescope imaging

    SciTech Connect (OSTI)

    Kelly, Patrick L.; Fox, Ori D.; Filippenko, Alexei V.; Shen, Ken J.; Zheng, WeiKang; Graham, Melissa L.; Tucker, Brad E.; Cenko, S. Bradley; Schaefer, Gail

    2014-07-20

    We constrain the properties of the progenitor system of the highly reddened Type Ia supernova (SN Ia) 2014J in Messier 82 (M82; d ? 3.5 Mpc). We determine the supernova (SN) location using Keck-II K-band adaptive optics images, and we find no evidence for flux from a progenitor system in pre-explosion near-ultraviolet through near-infrared Hubble Space Telescope (HST) images. Our upper limits exclude systems having a bright red giant companion, including symbiotic novae with luminosities comparable to that of RS Ophiuchi. While the flux constraints are also inconsistent with predictions for comparatively cool He-donor systems (T ? 35,000 K), we cannot preclude a system similar to V445 Puppis. The progenitor constraints are robust across a wide range of R{sub V} and A{sub V} values, but significantly greater values than those inferred from the SN light curve and spectrum would yield proportionally brighter luminosity limits. The comparatively faint flux expected from a binary progenitor system consisting of white dwarf stars would not have been detected in the pre-explosion HST imaging. Infrared HST exposures yield more stringent constraints on the luminosities of very cool (T < 3000 K) companion stars than was possible in the case of SN Ia 2011fe.

  19. PRODUCTION OF THE p-PROCESS NUCLEI IN THE CARBON-DEFLAGRATION MODEL FOR TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Kusakabe, Motohiko; Iwamoto, Nobuyuki; Nomoto, Ken'ichi E-mail: iwamoto.nobuyuki@jaea.go.jp

    2011-01-01

    We calculate the nucleosynthesis of proton-rich isotopes in the carbon-deflagration model for Type Ia supernovae (SNe Ia). The seed abundances are obtained by calculating the s-process nucleosynthesis that is expected to occur in the repeating helium shell flashes on the carbon-oxygen (CO) white dwarf (WD) during mass accretion from a binary companion. When the deflagration wave passes through the outer layer of the CO WD, p-nuclei are produced by photodisintegration reactions on s-nuclei in a region where the peak temperature ranges from 1.9 to 3.6 x 10{sup 9} K. We confirm the sensitivity of the p-process on the initial distribution of s-nuclei. We show that the initial C/O ratio in the WD does not affect much the yield of p-nuclei. On the other hand, the abundance of {sup 22}Ne left after s-processing has a large influence on the p-process via the {sup 22}Ne({alpha},n) reaction. We find that about 50% of p-nuclides are co-produced when normalized to their solar abundances in all adopted cases of seed distribution. Mo and Ru, which are largely underproduced in Type II supernovae (SNe II), are produced more than in SNe II although they are underproduced with respect to the yield levels of other p-nuclides. The ratios between p-nuclei and iron in the ejecta are larger than the solar ratios by a factor of 1.2. We also compare the yields of oxygen, iron, and p-nuclides in SNe Ia and SNe II and suggest that SNe Ia could make a larger contribution than SNe II to the solar system content of p-nuclei.

  20. Systematic uncertainties associated with the cosmological analysis of the first Pan-STARRS1 type Ia supernova sample

    SciTech Connect (OSTI)

    Scolnic, D.; Riess, A.; Brout, D.; Rodney, S. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Rest, A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Huber, M. E.; Tonry, J. L. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Foley, R. J.; Chornock, R.; Berger, E.; Soderberg, A. M.; Stubbs, C. W.; Kirshner, R. P.; Challis, P.; Czekala, I.; Drout, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Narayan, G. [Department of Physics, Harvard University, 17 Oxford Street, Cambridge, MA 02138 (United States); Smartt, S. J.; Botticella, M. T. [Astrophysics Research Centre, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Schlafly, E. [Max Planck Institute for Astronomy, Konigstuhl 17, D-69117 Heidelberg (Germany); and others

    2014-11-01

    We probe the systematic uncertainties from the 113 Type Ia supernovae (SN Ia) in the Pan-STARRS1 (PS1) sample along with 197 SN Ia from a combination of low-redshift surveys. The companion paper by Rest et al. describes the photometric measurements and cosmological inferences from the PS1 sample. The largest systematic uncertainty stems from the photometric calibration of the PS1 and low-z samples. We increase the sample of observed Calspec standards from 7 to 10 used to define the PS1 calibration system. The PS1 and SDSS-II calibration systems are compared and discrepancies up to ?0.02 mag are recovered. We find uncertainties in the proper way to treat intrinsic colors and reddening produce differences in the recovered value of w up to 3%. We estimate masses of host galaxies of PS1 supernovae and detect an insignificant difference in distance residuals of the full sample of 0.037 0.031 mag for host galaxies with high and low masses. Assuming flatness and including systematic uncertainties in our analysis of only SNe measurements, we find w =?1.120{sub ?0.206}{sup +0.360}(Stat){sub ?0.291}{sup +0.269}(Sys). With additional constraints from Baryon acoustic oscillation, cosmic microwave background (CMB) (Planck) and H {sub 0} measurements, we find w=?1.166{sub ?0.069}{sup +0.072} and ?{sub m}=0.280{sub ?0.012}{sup +0.013} (statistical and systematic errors added in quadrature). The significance of the inconsistency with w = 1 depends on whether we use Planck or Wilkinson Microwave Anisotropy Probe measurements of the CMB: w{sub BAO+H0+SN+WMAP}=?1.124{sub ?0.065}{sup +0.083}.

  1. A Chandrasekhar mass progenitor for the Type Ia supernova remnant 3C 397 from the enhanced abundances of nickel and manganese

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yamaguchi, Hiroya; Badenes, Carles; Foster, Adam R.; Bravo, Eduardo; Williams, Brian J.; Maeda, Keiichi; Nobukawa, Masayoshi; Eriksen, Kristoffer A.; Brickhouse, Nancy S.; Petre, Robert; et al

    2015-03-12

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11–0.24 and 0.018–0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only bemore » achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Altogether with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.« less

  2. A Chandrasekhar mass progenitor for the Type Ia supernova remnant 3C 397 from the enhanced abundances of nickel and manganese

    SciTech Connect (OSTI)

    Yamaguchi, Hiroya; Badenes, Carles; Foster, Adam R.; Bravo, Eduardo; Williams, Brian J.; Maeda, Keiichi; Nobukawa, Masayoshi; Eriksen, Kristoffer A.; Brickhouse, Nancy S.; Petre, Robert; Koyama, Katsuji

    2015-03-12

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11–0.24 and 0.018–0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only be achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Altogether with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.

  3. ASYMMETRY IN THE OBSERVED METAL-RICH EJECTA OF THE GALACTIC TYPE IA SUPERNOVA REMNANT G299.22.9

    SciTech Connect (OSTI)

    Post, Seth; Park, Sangwook [Department of Physics, University of Texas at Arlington, Arlington, Box 19059, TX 76019 (United States); Badenes, Carles [Department of Physics and Astronomy and Pittsburgh Particle Physics, Astrophysics, and Cosmology Center (PITT-PACC), University of Pittsburgh, 3941 OHara Street, Pittsburgh, PA 15260 (United States); Burrows, David N. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Hughes, John P. [Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854-8019 (United States); Lee, Jae-Joon [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Mori, Koji [Department of Applied Physics, University of Miyazaki, 1-1 Gakuen Kibana-dai Nishi, Miyazaki 889-2192 (Japan); Slane, Patrick O., E-mail: seth.post@mavs.uta.edu, E-mail: badenes@pitt.edu, E-mail: burrows@astro.psu.edu, E-mail: jph@physics.rutgers.edu, E-mail: mori@astro.miyazaki-u.ac.jp, E-mail: slane@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2014-09-01

    We have performed a deep Chandra observation of the Galactic TypeIa supernova remnant G299.22.9. Here we report the initial results from our imaging and spectral analysis. The observed abundance ratios of the central ejecta are in good agreement with those predicted by delayed-detonation TypeIa supernovae models. We reveal inhomogeneous spatial and spectral structures of metal-rich ejecta in G299.22.9. The Fe/Si abundance ratio in the northern part of the central ejecta region is higher than that in the southern part. A significant continuous elongation of ejecta material extends out to the western outermost boundary of the remnant. In this western elongation, both the Si and Fe are enriched with a similar abundance ratio to that in the southern part of the central ejecta region. These structured distributions of metal-rich ejecta material suggest that this TypeIa supernova might have undergone a significantly asymmetric explosion and/or has been expanding into a structured medium.

  4. Radiogenic p-isotopes from type Ia supernova, nuclear physics uncertainties, and galactic chemical evolution compared with values in primitive meteorites

    SciTech Connect (OSTI)

    Travaglio, C.; Gallino, R.; Rauscher, T.; Dauphas, N.; Rpke, F. K.; Hillebrandt, W. E-mail: claudia.travaglio@b2fh.org

    2014-11-10

    The nucleosynthesis of proton-rich isotopes is calculated for multi-dimensional Chandrasekhar-mass models of Type Ia supernovae (SNe Ia) with different metallicities. The predicted abundances of the short-lived radioactive isotopes {sup 92}Nb, {sup 97,} {sup 98}Tc, and {sup 146}Sm are given in this framework. The abundance seeds are obtained by calculating s-process nucleosynthesis in the material accreted onto a carbon-oxygen white dwarf from a binary companion. A fine grid of s-seeds at different metallicities and {sup 13}C-pocket efficiencies is considered. A galactic chemical evolution model is used to predict the contribution of SN Ia to the solar system p-nuclei composition measured in meteorites. Nuclear physics uncertainties are critical to determine the role of SNe Ia in the production of {sup 92}Nb and {sup 146}Sm. We find that, if standard Chandrasekhar-mass SNe Ia are at least 50% of all SN Ia, they are strong candidates for reproducing the radiogenic p-process signature observed in meteorites.

  5. DISPLAYING THE HETEROGENEITY OF THE SN 2002cx-LIKE SUBCLASS OF TYPE Ia SUPERNOVAE WITH OBSERVATIONS OF THE Pan-STARRS-1 DISCOVERED SN 2009ku

    SciTech Connect (OSTI)

    Narayan, G.; Foley, R. J.; Berger, E.; Chornock, R.; Rest, A.; Soderberg, A. M.; Kirshner, R. P.; Botticella, M. T.; Smartt, S.; Valenti, S.; Huber, M. E.; Scolnic, D.; Grav, T.; Burgett, W. S.; Chambers, K. C.; Flewelling, H. A.; Gates, G.; Kaiser, N.; Magnier, E. A.; Morgan, J. S. E-mail: rfoley@cfa.harvard.edu

    2011-04-10

    SN 2009ku, discovered by Pan-STARRS-1, is a Type Ia supernova (SN Ia), and a member of the distinct SN 2002cx-like class of SNe Ia. Its light curves are similar to the prototypical SN 2002cx, but are slightly broader and have a later rise to maximum in g. SN 2009ku is brighter ({approx}0.6 mag) than other SN 2002cx-like objects, peaking at M{sub V} = -18.4 mag, which is still significantly fainter than typical SNe Ia. SN 2009ku, which had an ejecta velocity of {approx}2000 km s{sup -1} at 18 days after maximum brightness, is spectroscopically most similar to SN 2008ha, which also had extremely low-velocity ejecta. However, SN 2008ha had an exceedingly low luminosity, peaking at M{sub V} = -14.2 mag, {approx}4 mag fainter than SN 2009ku. The contrast of high luminosity and low ejecta velocity for SN 2009ku is contrary to an emerging trend seen for the SN 2002cx class. SN 2009ku is a counterexample of a previously held belief that the class was more homogeneous than typical SNe Ia, indicating that the class has a diverse progenitor population and/or complicated explosion physics. As the first example of a member of this class of objects from the new generation of transient surveys, SN 2009ku is an indication of the potential for these surveys to find rare and interesting objects.

  6. Expectations for the hard x-ray continuum and gamma-ray line fluxes from the typE IA supernova SN 2014J in M82

    SciTech Connect (OSTI)

    The, Lih-Sin [Department of Physics and Astronomy, Clemson University, SC 29634 (United States); Burrows, Adam, E-mail: tlihsin@clemson.edu, E-mail: burrows@astro.princeton.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

    2014-05-10

    The hard X-ray continuum and gamma-ray lines from a Type Ia supernova dominate its integrated photon emissions and can provide unique diagnostics of the mass of the ejecta, the {sup 56}Ni yield and spatial distribution, its kinetic energy and expansion speed, and the mechanism of explosion. Such signatures and their time behavior 'X-ray' the bulk debris field in direct fashion, and do not depend on the ofttimes problematic and elaborate UV, optical, and near-infrared spectroscopy and radiative transfer that have informed the study of these events for decades. However, to date no hard photons have ever been detected from a Type Ia supernova in explosion. With the advent of the supernova SN 2014J in M82, at a distance of ?3.5 Mpc, this situation may soon change. Both NuSTAR and INTEGRAL have the potential to detect SN 2014J, and, if spectra and light curves can be measured, would usefully constrain the various explosion models published during the last ?30 yr. In support of these observational campaigns, we provide predictions for the hard X-ray continuum and gamma-line emissions for 15 Type Ia explosion models gleaned from the literature. The model set, containing as it does deflagration, delayed detonation, merger detonation, pulsational delayed detonation, and sub-Chandrasekhar helium detonation models, collectively spans a wide range of properties, and hence signatures. We provide a brief discussion of various diagnostics (with examples), but importantly make the spectral and line results available electronically to aid in the interpretation of the anticipated data.

  7. THE EFFECT OF THE PRE-DETONATION STELLAR INTERNAL VELOCITY PROFILE ON THE NUCLEOSYNTHETIC YIELDS IN TYPE Ia SUPERNOVA

    SciTech Connect (OSTI)

    Kim, Yeunjin; Jordan, G. C. IV; Graziani, Carlo; Lamb, D. Q.; Truran, J. W.; Meyer, B. S.

    2013-07-01

    A common model of the explosion mechanism of Type Ia supernovae is based on a delayed detonation of a white dwarf. A variety of models differ primarily in the method by which the deflagration leads to a detonation. A common feature of the models, however, is that all of them involve the propagation of the detonation through a white dwarf that is either expanding or contracting, where the stellar internal velocity profile depends on both time and space. In this work, we investigate the effects of the pre-detonation stellar internal velocity profile and the post-detonation velocity of expansion on the production of {alpha}-particle nuclei, including {sup 56}Ni, which are the primary nuclei produced by the detonation wave. We perform one-dimensional hydrodynamic simulations of the explosion phase of the white dwarf for center and off-center detonations with five different stellar velocity profiles at the onset of the detonation. In order to follow the complex flows and to calculate the nucleosynthetic yields, approximately 10,000 tracer particles were added to every simulation. We observe two distinct post-detonation expansion phases: rarefaction and bulk expansion. Almost all the burning to {sup 56}Ni occurs only in the rarefaction phase, and its expansion timescale is influenced by pre-existing flow structure in the star, in particular by the pre-detonation stellar velocity profile. We find that the mass fractions of the {alpha}-particle nuclei, including {sup 56}Ni, are tight functions of the empirical physical parameter {rho}{sub up}/v{sub down}, where {rho}{sub up} is the mass density immediately upstream of the detonation wave front and v{sub down} is the velocity of the flow immediately downstream of the detonation wave front. We also find that v{sub down} depends on the pre-detonation flow velocity. We conclude that the properties of the pre-existing flow, in particular the internal stellar velocity profile, influence the final isotopic composition of burned

  8. Type Ia Supernovae

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    that the universe is undergoing an accelerated expansion - a result which fits the General Relativity if a yet unknown form of "dark" energy is assumed to dominate the...

  9. Cosmological constraints from measurements of type Ia supernovae discovered during the first 1.5 yr of the Pan-STARRS1 survey

    SciTech Connect (OSTI)

    Rest, A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Scolnic, D.; Riess, A.; Rodney, S.; Brout, D. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Foley, R. J.; Chornock, R.; Berger, E.; Soderberg, A. M.; Stubbs, C. W.; Kirshner, R. P.; Challis, P.; Czekala, I.; Drout, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Huber, M. E.; Tonry, J. L. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Narayan, G. [Department of Physics, Harvard University, 17 Oxford Street, Cambridge, MA 02138 (United States); Smartt, S. J. [Astrophysics Research Centre, School of Mathematics and Physics, Queens University Belfast, Belfast BT71NN (United Kingdom); Schlafly, E. [Max Planck Institute for Astronomy, Knigstuhl 17, D-69117 Heidelberg (Germany); Botticella, M. T. [INAF-Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, I-80131 Napoli (Italy); and others

    2014-11-01

    We present griz {sub P1} light curves of 146 spectroscopically confirmed Type Ia supernovae (SNe Ia; 0.03 < z < 0.65) discovered during the first 1.5 yr of the Pan-STARRS1 Medium Deep Survey. The Pan-STARRS1 natural photometric system is determined by a combination of on-site measurements of the instrument response function and observations of spectrophotometric standard stars. We find that the systematic uncertainties in the photometric system are currently 1.2% without accounting for the uncertainty in the Hubble Space Telescope Calspec definition of the AB system. A Hubble diagram is constructed with a subset of 113 out of 146 SNe Ia that pass our light curve quality cuts. The cosmological fit to 310 SNe Ia (113 PS1 SNe Ia + 222 light curves from 197 low-z SNe Ia), using only supernovae (SNe) and assuming a constant dark energy equation of state and flatness, yields w=?1.120{sub ?0.206}{sup +0.360}(Stat){sub ?0.291}{sup +0.269}(Sys). When combined with BAO+CMB(Planck)+H {sub 0}, the analysis yields ?{sub M}=0.280{sub ?0.012}{sup +0.013} and w=?1.166{sub ?0.069}{sup +0.072} including all identified systematics. The value of w is inconsistent with the cosmological constant value of 1 at the 2.3? level. Tension endures after removing either the baryon acoustic oscillation (BAO) or the H {sub 0} constraint, though it is strongest when including the H {sub 0} constraint. If we include WMAP9 cosmic microwave background (CMB) constraints instead of those from Planck, we find w=?1.124{sub ?0.065}{sup +0.083}, which diminishes the discord to <2?. We cannot conclude whether the tension with flat ?CDM is a feature of dark energy, new physics, or a combination of chance and systematic errors. The full Pan-STARRS1 SN sample with ?three times as many SNe should provide more conclusive results.

  10. OPTICAL AND NEAR-INFRARED POLARIMETRY OF HIGHLY REDDENED Type Ia SUPERNOVA 2014J: PECULIAR PROPERTIES OF DUST IN M82

    SciTech Connect (OSTI)

    Kawabata, K. S.; Akitaya, H.; Itoh, R.; Moritani, Y. [Hiroshima Astrophysical Science Center, Hiroshima University, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Yamanaka, M. [Department of Physics, Faculty of Science and Engineering, Konan University, Okamoto, Kobe, Hyogo 658-8501 (Japan); Maeda, K.; Nogami, D. [Department of Astronomy, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Ui, T.; Kawabata, M.; Mori, K.; Takaki, K.; Ueno, I.; Chiyonobu, S.; Harao, T.; Matsui, R.; Miyamoto, H.; Nagae, O. [Department of Physical Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526 (Japan); Nomoto, K.; Suzuki, N. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Tanaka, M., E-mail: kawabtkj@hiroshima-u.ac.jp [National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan); and others

    2014-11-01

    We present optical and near-infrared multi-band linear polarimetry of the highly reddened Type Ia supernova (SN) 2014J that appeared in M82. SN 2014J exhibits large polarization at shorter wavelengths, e.g., 4.8% in the B band, which decreases rapidly at longer wavelengths, while the position angle of the polarization remains at approximately 40 over the observed wavelength range. These polarimetric properties suggest that the observed polarization is likely predominantly caused by the interstellar dust within M82. Further analysis shows that the polarization peaks at a wavelengths much shorter than those obtained for the Galactic dust. The wavelength dependence of the polarization can be better described by an inverse power law rather than by the Serkowski law for Galactic interstellar polarization. These points suggest that the nature of the dust in M82 may be different from that in our Galaxy, with polarizing dust grains having a mean radius of <0.1 ?m.

  11. TYPE Ia SUPERNOVA REMNANT SHELL AT z = 3.5 SEEN IN THE THREE SIGHTLINES TOWARD THE GRAVITATIONALLY LENSED QSO B1422+231

    SciTech Connect (OSTI)

    Hamano, Satoshi; Kobayashi, Naoto [Institute of Astronomy, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Kondo, Sohei [Koyama Astronomical Observatory, Kyoto-Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto 603-8555 (Japan); Tsujimoto, Takuji [National Astronomical Observatory of Japan and Department of Astronomical Science, Graduate University for Advanced Studies, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Okoshi, Katsuya [Faculty of Industrial Science and Technology, Tokyo University of Science, 102-1 Tomino, Oshamanbe, Hokkaido 049-3514 (Japan); Shigeyama, Toshikazu, E-mail: hamano@ioa.s.u-tokyo.ac.jp [Research Center for the Early Universe, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan)

    2012-08-01

    Using the Subaru 8.2 m Telescope with the IRCS Echelle spectrograph, we obtained high-resolution (R = 10,000) near-infrared (1.01-1.38 {mu}m) spectra of images A and B of the gravitationally lensed QSO B1422+231 (z = 3.628) consisting of four known lensed images. We detected Mg II absorption lines at z = 3.54, which show a large variance of column densities ({approx}0.3 dex) and velocities ({approx}10 km s{sup -1}) between sightlines A and B with a projected separation of only 8.4h{sup -1}{sub 70} pc at that redshift. This is the smallest spatial structure of the high-z gas clouds ever detected after Rauch et al. found a 20 pc scale structure for the same z = 3.54 absorption system using optical spectra of images A and C. The observed systematic variances imply that the system is an expanding shell as originally suggested by Rauch et al. By combining the data for three sightlines, we managed to constrain the radius and expansion velocity of the shell ({approx}50-100 pc, 130 km s{sup -1}), concluding that the shell is truly a supernova remnant (SNR) rather than other types of shell objects, such as a giant H II region. We also detected strong Fe II absorption lines for this system, but with much broader Doppler width than that of {alpha}-element lines. We suggest that this Fe II absorption line originates in a localized Fe II-rich gas cloud that is not completely mixed with plowed ambient interstellar gas clouds showing other {alpha}-element low-ion absorption lines. Along with the Fe richness, we conclude that the SNR is produced by an SN Ia explosion.

  12. Systematic Effects in Type-1a Supernovae Surveys from Host Galaxy Spectra

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Systematic Effects in Type-1a Supernovae Surveys from Host Galaxy Spectra Citation Details In-Document Search Title: Systematic Effects in Type-1a Supernovae Surveys from Host Galaxy Spectra The physical relation between the properties of Type Ia supernovae and their host galaxies is investigated. Such supernovae are used to constrain the properties of dark energy, making it crucial to understand their physical properties and to check for systematic

  13. TYCHO SN 1572: A NAKED Ia SUPERNOVA REMNANT WITHOUT AN ASSOCIATED AMBIENT MOLECULAR CLOUD

    SciTech Connect (OSTI)

    Tian, W. W.; Leahy, D. A.

    2011-03-10

    The historical supernova remnant (SNR) Tycho SN 1572 originates from the explosion of a normal Type Ia supernova that is believed to have originated from a carbon-oxygen white dwarf in a binary system. We analyze the 21 cm continuum, H I, and {sup 12}CO-line data from the Canadian Galactic Plane Survey in the direction of SN 1572 and the surrounding region. We construct H I absorption spectra to SN 1572 and three nearby compact sources. We conclude that SN 1572 has no molecular cloud interaction, which argues against previous claims that a molecular cloud is interacting with the SNR. This new result does not support a recent claim that dust, newly detected by AKARI, originates from such an SNR-cloud interaction. We suggest that the SNR has a kinematic distance of 2.5-3.0 kpc based on a nonlinear rotational curve model. Very high energy {gamma}-ray emission from the remnant has been detected by the VERITAS telescope, so our result shows that its origin should not be an SNR-cloud interaction. Both radio and X-ray observations support that SN 1572 is an isolated Type Ia SNR.

  14. Supernova Hunting with Supercomputers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Supernova Hunting with Supercomputers Supernova Hunting with Supercomputers Berkeley researchers provide "roadmap" and tools for finding and studying Type Ia supernovae in their natural habitat May 20, 2015 Contact: Linda Vu, +1 510 495 2402, lvu@lbl.gov sn-star.jpg Simulation of the expanding debris from a supernova explosion (shown in red) running over and shredding a nearby star (shown in blue). Image credit: Daniel Kasen, Berkeley Lab/ UC Berkeley Type Ia supernovae are famous for

  15. Discovering the Nature of Dark Energy: Towards Better Distances from Type

    Office of Scientific and Technical Information (OSTI)

    Ia Supernovae -- Final Technical Report (Technical Report) | SciTech Connect Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae -- Final Technical Report Citation Details In-Document Search Title: Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae -- Final Technical Report Type Ia supernovae (SNe Ia; exploding white-dwarf stars) were the key to the Nobel-worthy 1998 discovery and subsequent verification that the

  16. SPECTROPOLARIMETRY OF THE TYPE Ia SN 2007sr TWO MONTHS AFTER MAXIMUM LIGHT

    SciTech Connect (OSTI)

    Zelaya, P.; Quinn, J. R.; Clocchiatti, A.; Baade, D.; Patat, F.; Hoeflich, P.; Maund, J.; Wang, L.; Wheeler, J. C.

    2013-02-01

    We present late-time spectropolarimetric observations of SN 2007sr, obtained with the Very Large Telescope at the ESO Paranal Observatory when the object was 63 days after maximum light. The late-time spectrum displays strong line polarization in the Ca II absorption features. SN 2007sr adds to the case of some normal Type Ia supernovae that show high line polarization or repolarization at late times, a fact that might be connected with the presence of high-velocity features at early times.

  17. Supernova Twins: Making Standard Candles More Standard Than Ever

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Less than 20 years ago the world learned that the universe is expanding ever faster, propelled by dark energy. The discovery was made possible by Type Ia supernovae; ...

  18. Supernova Discoveries from the Nearby Supernova Factory (SNfactory...

    Office of Scientific and Technical Information (OSTI)

    data on more Type Ia supernovae than have ever been studied in a single project before, and in so doing, to answer some fundamental questions about the nature of the universe. ...

  19. Confirmed: Stellar Behemoth Self-Destructs in Type IIb Supernova

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Confirmed: Stellar Behemoth Self-Destructs in Type IIb Supernova Confirmed: Stellar Behemoth Self-Destructs in Type IIb Supernova Berkeley Researchers Help Catch a Wolf-Rayet Hours After it Goes Supernova May 21, 2014 Contact: Linda Vu, +1 510 495 2402, lvu@lbl.gov SN2013cu-.jpg A star in a distant galaxy explodes as a supernova: While observing a galaxy known as UGC 9379 (left; image from the Sloan Digital Sky Survey; SDSS) located about 360 million light years away from Earth, the team

  20. Optical and ultraviolet observations of the narrow-lined type Ia SN 2012fr in NGC 1365

    SciTech Connect (OSTI)

    Zhang, Ju-Jia; Bai, Jin-Ming; Wang, Bo; Liu, Zheng-Wei [Yunnan Observatories (YNAO), Chinese Academy of Sciences, Kunming 650011 (China); Wang, Xiao-Feng; Zhao, Xu-Lin; Chen, Jun-Cheng [Physics Department and Tsinghua Center for Astrophysics (THCA), Tsinghua University, Beijing 100084 (China); Zhang, Tian-Meng, E-mail: jujia@ynao.ac.cn, E-mail: baijinming@ynao.ac.cn, E-mail: wang_xf@mail.tsinghua.edu.cn [National Astronomical Observatories of China (NAOC), Chinese Academy of Sciences, Beijing 100012 (China)

    2014-07-01

    Extensive optical and ultraviolet (UV) observations of the type Ia supernova (SN Ia) 2012fr are presented in this paper. It has a relatively high luminosity, with an absolute B-band peak magnitude of about 19.5 mag and a smaller post-maximum decline rate than normal SNe Ia (e.g., ?m {sub 15}(B) =0.85 0.05 mag). Based on the UV and optical light curves, we derived that a {sup 56}Ni mass of about 0.88 M {sub ?} was synthesized in the explosion. The earlier spectra are characterized by noticeable high-velocity features of Si II ?6355 and Ca II with velocities in the range of ?22, 000-25, 000 km s{sup 1}. At around the maximum light, these spectral features are dominated by the photospheric components which are noticeably narrower than normal SNe Ia. The post-maximum velocity of the photosphere remains almost constant at ?12,000 km s{sup 1} for about one month, reminiscent of the behavior of some luminous SNe Ia like SN 1991T. We propose that SN 2012fr may represent a subset of the SN 1991T-like SNe Ia viewed in a direction with a clumpy or shell-like structure of ejecta, in terms of a significant level of polarization reported in Maund et al. in 2013.

  1. High Statistics Study of Nearby Type 1a Supernovae. QUEST Camera...

    Office of Scientific and Technical Information (OSTI)

    Statistics Study of Nearby Type 1a Supernovae. QUEST Camera Short Term Maintenance: Final Technical Report Baltay, Charles 79 ASTRONOMY AND ASTROPHYSICS Study of Type 1a Supernovae...

  2. A Chandrasekhar mass progenitor for the Type Ia supernova remnant...

    Office of Scientific and Technical Information (OSTI)

    for Astrophysics, Cambridge, MA (United States) Univ. of Pittsburgh, Pittsburgh, PA (United States) Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States) Univ. ...

  3. THE ABSOLUTE MAGNITUDES OF TYPE Ia SUPERNOVAE IN THE ULTRAVIOLET...

    Office of Scientific and Technical Information (OSTI)

    Authors: Brown, Peter J. ; Roming, Peter W. A. ; Ciardullo, Robin ; Gronwall, Caryl ; Hoversten, Erik A. ; Pritchard, Tyler 1 ; Milne, Peter 2 ; Bufano, Filomena ; Mazzali, ...

  4. Sweetspot: Near-infrared observations of 13 type Ia supernovae...

    Office of Scientific and Technical Information (OSTI)

    Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States) Publication Date: 2014-04-01 OSTI Identifier: 22357282 Resource ...

  5. THE ULTRAVIOLET BRIGHTEST TYPE Ia SUPERNOVA 2011de (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    be modeled with additional flux from the shock of the ejecta hitting a relatively large ... similar UV luminosities can be intrinsic or caused by other forms of shock interaction. ...

  6. Turbulence-Flame Interactions in Type Ia Supernovae (Journal...

    Office of Scientific and Technical Information (OSTI)

    1 ; Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 2 ; Department of Physics and Astronomy, Stony Brook University, ...

  7. Improved Distances to Type Ia Supernovae withMulticolor Light...

    Office of Scientific and Technical Information (OSTI)

    This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and ... We present an updated version of the Multicolor Light Curve Shape method to measure ...

  8. Flames in Type Ia Supernova: Deflagration-Detonation Transition...

    Office of Scientific and Technical Information (OSTI)

    Language: English Word Cloud More Like This Full Text Journal Articles Find in Google Scholar Find in Google Scholar Search WorldCat Search WorldCat to find libraries that may hold ...

  9. Closest Type Ia Supernova in Decades Solves a Cosmic Mystery

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    observations of SN 2011fe were carried out at the Liverpool Telescope at La Palma in the Canary Islands, followed within hours by the Shane Telescope at Lick Observatory in...

  10. Improved Constraints on Type Ia Supernova Host Galaxy Properties...

    Office of Scientific and Technical Information (OSTI)

    Astrophys. ; Smith, Mathew ; Cape Town U. ; Bassett, Bruce ; South African Astron. Observ. Cape Town U., Dept. Math. African Inst. Math. Sci., Cape Town ; Frieman, Joshua A. ; ...

  11. Supernova Discoveries from the Nearby Supernova Factory (SNfactory)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    SNfactory International Collaboration,

    The Nearby Supernova Factory is an experiment designed to collect data on more Type Ia supernovae than have ever been studied in a single project before, and in so doing, to answer some fundamental questions about the nature of the universe. Type Ia supernovae are extraordinarily bright, remarkably uniform objects which make excellent "standard candles" for measuring the expansion rate of the universe. However, such stellar explosions are very rare, occurring only a couple of times per millenium in a typical galaxy, and remaining bright enough to detect only for a few weeks. Previous studies of Type Ia supernovae led to the discovery of the mysterious "dark energy" that is causing the universe to expand at an accelerating rate. To reduce the statistical uncertainties in previous experimental data, extensive spectral and photometric monitoring of more Type Ia supernovae is required. The SNfactory collaboration has built an automated system consisting of specialized software and custom-built hardware that systematically searches the sky for new supernovae, screens potential candidates, then performs multiple spectral and photometric observations on each supernova. These observations are stored in a database to be made available to supernova researchers world-wide for further study and analysis [copied from http://snfactory.lbl.gov/snf/snf-about.html]. Users must register and agree to the open access honor system. Finding charts are in FITS format and may not be accessible through normal browser settings.

  12. Systematic Effects in Type-1a Supernovae Surveys from Host Galaxy...

    Office of Scientific and Technical Information (OSTI)

    Systematic Effects in Type-1a Supernovae Surveys from Host Galaxy Spectra Strauss, Michael A. Princeton University 79 ASTRONOMY AND ASTROPHYSICS Cosmology, supernovae, stellar...

  13. Spectroscopic Observations and Analysis of the Unusual Type Ia SN1999ac

    SciTech Connect (OSTI)

    Garavini, G.; Aldering, G.; Amadon, A.; Amanullah, R.; Astier,P.; Balland, C.; Blanc, G.; Conley, A.; Dahlen, T.; Deustua, S.E.; Ellis,R.; Fabbro, S.; Fadeyev, V.; Fan, X.; Folatelli, G.; Frye, B.; Gates,E.L.; Gibbons, R.; Goldhaber, G.; Goldman, B.; Goobar, A.; Groom, D.E.; Haissinski, J.; Hardin, D.; Hook, I.; Howell, D.A.; Kent, S.; Kim, A.G.; Knop, R.A.; Kowalski, M.; Kuznetsova, N.; Lee, B.C.; Lidman, C.; Mendez,J.; Miller, G.J.; Moniez, M.; Mouchet, M.; Mourao, A.; Newberg, H.; Nobili, S.; Nugent, P.E.; Pain, R.; Perdereau, O.; Perlmutter, S.; Quimby, R.; Regnault, N.; Rich, J.; Richards, G.T.; Ruiz-Lapuente, P.; Schaefer, B.E.; Schahmaneche, K.; Smith, E.; Spadafora, A.L.; Stanishev,V.; Thomas, R.C.; Walton, N.A.; Wang, L.; Wood-Vasey, W.M.

    2005-07-12

    The authors present optical spectra of the peculiar Type Ia supernova (SN Ia) 1999ac. The data extend from -15 to +42 days with respect to B-band maximum and reveal an event that is unusual in several respects. prior to B-band maximum, the spectra resemble those of SN 1999aa, a slowly declining event, but possess stronger Si II and Ca II signatures (more characteristic of a spectroscopically normal SN). Spectra after B-band maximum appear more normal. The expansion velocities inferred from the Iron lines appear to be lower than average; whereas, the expansion velocity inferred from Calcium H and K are higher than average. The expansion velocities inferred from the Iron lines appear to be lower than average; whereas, the expansion velocity inferred from Calcium H and K are higher than average. The expansion velocities inferred from Si II are among the slowest ever observed, though SN 1999ac is not particularly dim. The analysis of the parameters v{sub 10}(Si II), R(Si II), v, and {Delta}m{sub 15} further underlines the unique characteristics of SN 1999ac. They find convincing evidence of C II {lambda}6580 in the day -15 spectrum with ejection velocity v > 16,000 km s{sup -1}, but this signature disappears by day -9. This rapid evolution at early times highlights the importance of extremely early-time spectroscopy.

  14. EARLY OBSERVATIONS AND ANALYSIS OF THE TYPE Ia SN 2014J IN M82

    SciTech Connect (OSTI)

    Marion, G. H.; Vinkó, J.; Sand, D. J.; Hsiao, E. Y.; Banerjee, D. P. K.; Joshi, V.; Venkataraman, V.; Ashok, N. M.; Valenti, S.; Howell, D. A.; Stritzinger, M. D.; Amanullah, R.; Johansson, J.; Binzel, R. P.; Bochanski, J. J.; Bryngelson, G. L.; Burns, C. R.; Drozdov, D.; Fieber-Beyer, S. K.; Graham, M. L.; and others

    2015-01-01

    We present optical and near infrared (NIR) observations of the nearby Type Ia SN 2014J. Seventeen optical and 23 NIR spectra were obtained from 10 days before (–10d) to 10 days after (+10d) the time of maximum B-band brightness. The relative strengths of absorption features and their patterns of development can be compared at one day intervals throughout most of this period. Carbon is not detected in the optical spectra, but we identify C I λ1.0693 in the NIR spectra. Mg II lines with high oscillator strengths have higher initial velocities than other Mg II lines. We show that the velocity differences can be explained by differences in optical depths due to oscillator strengths. The spectra of SN 2014J show that it is a normal SN Ia, but many parameters are near the boundaries between normal and high-velocity subclasses. The velocities for O I, Mg II, Si II, S II, Ca II, and Fe II suggest that SN 2014J has a layered structure with little or no mixing. That result is consistent with the delayed detonation explosion models. We also report photometric observations, obtained from –10d to +29d, in the UBVRIJH and K{sub s} bands. The template fitting package SNooPy is used to interpret the light curves and to derive photometric parameters. Using R{sub V} = 1.46, which is consistent with previous studies, SNooPy finds that A{sub V} = 1.80 for E(B – V){sub host} = 1.23 ± 0.06 mag. The maximum B-band brightness of –19.19 ± 0.10 mag was reached on February 1.74 UT ± 0.13 days and the supernova has a decline parameter, Δm {sub 15}, of 1.12 ± 0.02 mag.

  15. Possible detection of the stellar donor or remnant for the type Iax supernova 2008ha

    SciTech Connect (OSTI)

    Foley, Ryan J. [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States); McCully, Curtis; Jha, Saurabh W. [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Bildsten, Lars [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Fong, Wen-fai [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Narayan, Gautham [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719-4933 (United States); Rest, Armin [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Stritzinger, Maximilian D. [Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Aarhus C (Denmark)

    2014-09-01

    Type Iax supernovae (SNe Iax) are thermonuclear explosions that are related to SNe Ia, but are physically distinct. The most important differences are that SNe Iax have significantly lower luminosity (1%-50% that of typical SNe Ia), lower ejecta mass (?0.1-0.5 M {sub ?}), and may leave a bound remnant. The most extreme SN Iax is SN 2008ha, which peaked at M{sub V} = 14.2 mag, about 5 mag below that of typical SNe Ia. Here, we present Hubble Space Telescope (HST) images of UGC 12682, the host galaxy of SN 2008ha, taken 4.1 yr after the peak brightness of SN 2008ha. In these deep, high-resolution images, we detect a source coincident (0.86 HST pixels; 0.''043; 1.1?) with the position of SN 2008ha with M {sub F814W} = 5.4 mag. We determine that this source is unlikely to be a chance coincidence, but that scenario cannot be completely ruled out. If this source is directly related to SN 2008ha, it is either the luminous bound remnant of the progenitor white dwarf (WD) or its companion star. The source is consistent with being an evolved >3 M {sub ?} initial mass star, and is significantly redder than the SN Iax 2012Z progenitor system, the first detected progenitor system for a thermonuclear SN. If this source is the companion star for SN 2008ha, there is a diversity in SN Iax progenitor systems, perhaps related to the diversity in SN Iax explosions. If the source is the bound remnant of the WD, it must have expanded significantly. Regardless of the nature of this source, we constrain the progenitor system of SN 2008ha to have an age of <80 Myr.

  16. High Statistics Study of Nearby Type 1a Supernovae. QUEST Camera Short Term

    Office of Scientific and Technical Information (OSTI)

    Maintenance: Final Technical Report (Technical Report) | SciTech Connect High Statistics Study of Nearby Type 1a Supernovae. QUEST Camera Short Term Maintenance: Final Technical Report Citation Details In-Document Search Title: High Statistics Study of Nearby Type 1a Supernovae. QUEST Camera Short Term Maintenance: Final Technical Report The Quest Camera was installed at the Palomar Obervatory in California. The camera was used to carry out a survey of low redshift Type 1a supernovae.The

  17. MID-IR SPECTRA OF TYPE Ia SN 2014J IN M82 SPANNING THE FIRST 4 MONTHS

    SciTech Connect (OSTI)

    Telesco, Charles M.; Li, Dan; Barnes, Peter J.; Mariñas, Naibí; Zhang, Han; Höflich, Peter; Álvarez, Carlos; Fernández, Sergio; Rebolo, Rafael; Hough, James H.; Levenson, N. A.; Pantin, Eric; Roche, Patrick E-mail: phoeflich77@gmail.com

    2015-01-10

    We present a time series of 8-13 μm spectra and photometry for SN 2014J obtained 57, 81, 108, and 137 days after the explosion using CanariCam on the Gran Telescopio Canarias. This is the first mid-IR time series ever obtained for a Type Ia supernova (SN Ia). These observations can be understood within the framework of the delayed detonation model and the production of ∼0.6 M {sub ☉} of {sup 56}Ni, consistent with the observed brightness, the brightness decline relation, and the γ-ray fluxes. The [Co III] line at 11.888 μm is particularly useful for evaluating the time evolution of the photosphere and measuring the amount of {sup 56}Ni and thus the mass of the ejecta. Late-time line profiles of SN 2014J are rather symmetric and not shifted in the rest frame. We see argon emission, which provides a unique probe of mixing in the transition layer between incomplete burning and nuclear statistical equilibrium. We may see [Fe III] and [Ni IV] emission, both of which are observed to be substantially stronger than indicated by our models. If the latter identification is correct, then we are likely observing stable Ni, which might imply central mixing. In addition, electron capture, also required for stable Ni, requires densities larger than ∼1 × 10{sup 9} g cm{sup –3}, which are expected to be present only in white dwarfs close to the Chandrasekhar limit. This study demonstrates that mid-IR studies of SNe Ia are feasible from the ground and provide unique information, but it also indicates the need for better atomic data.

  18. High Statistics Study of Nearby Type 1a Supernovae. QUEST Camera...

    Office of Scientific and Technical Information (OSTI)

    QUEST Camera Short Term Maintenance: Final Technical Report Citation Details In-Document Search Title: High Statistics Study of Nearby Type 1a Supernovae. QUEST Camera Short Term ...

  19. Study of Buoyancy-Driven Turbulent Nuclear Burning and Validation of Type

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ia Supernova Models | Argonne Leadership Computing Facility Study of Buoyancy-Driven Turbulent Nuclear Burning and Validation of Type Ia Supernova Models PI Name: Don Lamb PI Email: lamb@oddjob.uchicago.edu Institution: ASC/Alliance Flash Center, University of Chicago Allocation Program: INCITE Allocation Hours at ALCF: 80,000,000 Year: 2011 Research Domain: Physics We will study important aspects of Type Ia supernovae which are among the brightest and most powerful explosions in the

  20. THE FAST AND FURIOUS DECAY OF THE PECULIAR TYPE Ic SUPERNOVA 2005ek

    SciTech Connect (OSTI)

    Drout, M. R.; Soderberg, A. M.; Margutti, R.; Milisavljevic, D.; Sanders, N. E.; Chornock, R.; Foley, R. J.; Kirshner, R. P.; Chakraborti, S.; Challis, P.; Friedman, A.; Hicken, M.; Jensen, C.; Mazzali, P. A.; Parrent, J. T.; Filippenko, A. V.; Li, W.; Cenko, S. B.; Ganeshalingam, M.; Brown, P. J.; and others

    2013-09-01

    We present extensive multi-wavelength observations of the extremely rapidly declining Type Ic supernova (SN Ic), SN 2005ek. Reaching a peak magnitude of M{sub R} = -17.3 and decaying by {approx}3 mag in the first 15 days post-maximum, SN 2005ek is among the fastest Type I supernovae observed to date. The spectra of SN 2005ek closely resemble those of normal SN Ic, but with an accelerated evolution. There is evidence for the onset of nebular features at only nine days post-maximum. Spectroscopic modeling reveals an ejecta mass of {approx}0.3 M{sub Sun} that is dominated by oxygen ({approx}80%), while the pseudo-bolometric light curve is consistent with an explosion powered by {approx}0.03 M{sub Sun} of radioactive {sup 56}Ni. Although previous rapidly evolving events (e.g., SN 1885A, SN 1939B, SN 2002bj, SN 2010X) were hypothesized to be produced by the detonation of a helium shell on a white dwarf, oxygen-dominated ejecta are difficult to reconcile with this proposed mechanism. We find that the properties of SN 2005ek are consistent with either the edge-lit double detonation of a low-mass white dwarf or the iron-core collapse of a massive star, stripped by binary interaction. However, if we assume that the strong spectroscopic similarity of SN 2005ek to other SNe Ic is an indication of a similar progenitor channel, then a white-dwarf progenitor becomes very improbable. SN 2005ek may be one of the lowest mass stripped-envelope core-collapse explosions ever observed. We find that the rate of such rapidly declining Type I events is at least 1%-3% of the normal SN Ia rate.

  1. In the OSTI Collections: Supernovae | OSTI, US Dept of Energy Office of

    Office of Scientific and Technical Information (OSTI)

    Scientific and Technical Information Supernovae Article Acknowledgement: Dr. William N. Watson, Physicist DOE Office of Scientific and Technical Information Theory and supernova behavior Observations and their implications References Research Organizations Reports available through OSTI's SciTech Connect Data sets accessible through OSTI's DOE Data Explorer Additional References Figure 1. Supernova 1994D in the outskirts of the galaxy NGC 4526. This example of a type Ia supernova shows that

  2. Improved Dark Energy Constraints From ~ 100 New CfA Supernova...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Improved Dark Energy Constraints From 100 New CfA Supernova Type Ia Light Curves Citation Details In-Document Search Title: Improved Dark Energy Constraints From ...

  3. CONSTRAINING PHYSICAL PROPERTIES OF TYPE IIn SUPERNOVAE THROUGH RISE TIMES AND PEAK LUMINOSITIES

    SciTech Connect (OSTI)

    Moriya, Takashi J.; Maeda, Keiichi

    2014-08-01

    We investigate the diversity in the wind density, supernova ejecta energy, and ejecta mass in Type IIn supernovae based on their rise times and peak luminosities. We show that the wind density and supernova ejecta properties can be estimated independently if both the rise time and peak luminosity are observed. The peak luminosity is mostly determined by the supernova properties and the rise time can be used to estimate the wind density. We find that the ejecta energies of Type IIn supernovae need to vary by factors of 0.2-5 from the average if their ejecta masses are similar. The diversity in the observed rise times indicates that their wind densities vary by factors of 0.2-2 from the average. We show that Type IIn superluminous supernovae should have not only large wind density but also large ejecta energy and/or small ejecta mass to explain their large luminosities and the rise times at the same time. We also note that shock breakout does not necessarily occur in the wind even if it is optically thick, except for the case of superluminous supernovae, and we analyze the observational data both with and without assuming that the shock breakout occurs in the dense wind of Type IIn supernovae.

  4. No X-rays from the very nearby type Ia SN 2014J: Constraints on its environment

    SciTech Connect (OSTI)

    Margutti, R.; Parrent, J.; Kamble, A.; Soderberg, A. M.; Milisavljevic, D.; Drout, M. R.; Kirshner, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Foley, R. J. [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 W. Green Street, Urbana, IL 61801 (United States)

    2014-07-20

    Deep X-ray observations of the post-explosion environment around the very nearby Type Ia SN 2014J (d{sub L} = 3.5 Mpc) reveal no X-ray emission down to a luminosity L{sub x} < 7 10{sup 36} erg s{sup 1} (0.3-10 keV) at ?t ? 20 days after the explosion. We interpret this limit in the context of inverse Compton emission from upscattered optical photons by the supernova shock and constrain the pre-explosion mass-loss rate of the stellar progenitor system to be M-dot <10{sup ?9} M{sub ?} yr{sup ?1} (for wind velocity v{sub w} = 100 km s{sup 1}). Alternatively, the SN shock might be expanding into a uniform medium with density n{sub CSM} < 3 cm{sup 3}. These results rule out single-degenerate (SD) systems with steady mass loss until the terminal explosion and constrain the fraction of transferred material lost at the outer Lagrangian point to be ?1%. The allowed progenitors are (1) white dwarf-white dwarf progenitors, (2) SD systems with unstable hydrogen burning experiencing recurrent nova eruptions with recurrence time t < 300 yr, and (3) stars where the mass loss ceases before the explosion.

  5. A SPITZER SURVEY FOR DUST IN TYPE IIn SUPERNOVAE

    SciTech Connect (OSTI)

    Fox, Ori D.; Chevalier, Roger A.; Skrutskie, Michael F.; Soderberg, Alicia M.; Filippenko, Alexei V.; Ganeshalingam, Mohan; Silverman, Jeffrey M.; Smith, Nathan; Steele, Thea N.

    2011-11-01

    Recent observations suggest that Type IIn supernovae (SNe IIn) may exhibit late-time (>100 days) infrared (IR) emission from warm dust more than other types of core-collapse SNe. Mid-IR observations, which span the peak of the thermal spectral energy distribution, provide useful constraints on the properties of the dust and, ultimately, the circumstellar environment, explosion mechanism, and progenitor system. Due to the low SN IIn rate (<10% of all core-collapse SNe), few IR observations exist for this subclass. The handful of isolated studies, however, show late-time IR emission from warm dust that, in some cases, extends for five or six years post-discovery. While previous Spitzer/IRAC surveys have searched for dust in SNe, none have targeted the Type IIn subclass. This paper presents results from a warm Spitzer/IRAC survey of the positions of all 68 known SNe IIn within a distance of 250 Mpc between 1999 and 2008 that have remained unobserved by Spitzer more than 100 days post-discovery. The detection of late-time emission from 10 targets ({approx}15%) nearly doubles the database of existing mid-IR observations of SNe IIn. Although optical spectra show evidence for new dust formation in some cases, the data show that in most cases the likely origin of the mid-IR emission is pre-existing dust, which is continuously heated by optical emission generated by ongoing circumstellar interaction between the forward shock and circumstellar medium. Furthermore, an emerging trend suggests that these SNe decline at {approx}1000-2000 days post-discovery once the forward shock overruns the dust shell. The mass-loss rates associated with these dust shells are consistent with luminous blue variable progenitors.

  6. Rolling Hills (IA) | Open Energy Information

    Open Energy Info (EERE)

    Rolling Hills (IA) Jump to: navigation, search Name Rolling Hills (IA) Facility Rolling Hills (IA) Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service...

  7. Supernova 2010as: the lowest-velocity member of a family of flat-velocity type IIb supernovae

    SciTech Connect (OSTI)

    Folatelli, Gastn; Bersten, Melina C.; Nomoto, Ken'ichi [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Kuncarayakti, Hanindyo; Hamuy, Mario [Departamento de Astronoma, Universidad de Chile, Casilla 36-D, Santiago (Chile); Olivares Estay, Felipe; Pignata, Giuliano [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile); Anderson, Joseph P. [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago (Chile); Holmbo, Simon; Stritzinger, Maximilian [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Maeda, Keiichi [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Morrell, Nidia; Contreras, Carlos; Phillips, Mark M. [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Frster, Francisco [Center for Mathematical Modelling, Universidad de Chile, Avenida Blanco Encalada 2120 Piso 7, Santiago (Chile); Prieto, Jos Luis [Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Peyton Hall, Princeton, NJ 08544 (United States); Valenti, Stefano [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States); Afonso, Paulo; Altenmller, Konrad; Elliott, Jonny, E-mail: gaston.folatelli@ipmu.jp [Max-Planck-Institut fr extraterrestrische Physik, Giessenbachstrae 1, D-85740 Garching (Germany); and others

    2014-09-01

    We present extensive optical and near-infrared photometric and spectroscopic observations of the stripped-envelope supernova SN 2010as. Spectroscopic peculiarities such as initially weak helium features and low expansion velocities with a nearly flat evolution place this object in the small family of events previously identified as transitional Type Ib/c supernovae (SNe). There is ubiquitous evidence of hydrogen, albeit weak, in this family of SNe, indicating that they are in fact a peculiar kind of Type IIb SNe that we name 'flat-velocity' Type IIb. The flat-velocity evolutionwhich occurs at different levels between 6000 and 8000 km s{sup 1} for different SNesuggests the presence of a dense shell in the ejecta. Despite the spectroscopic similarities, these objects show surprisingly diverse luminosities. We discuss the possible physical or geometrical unification picture for such diversity. Using archival Hubble Space Telescope images, we associate SN 2010as with a massive cluster and derive a progenitor age of ?6 Myr, assuming a single star-formation burst, which is compatible with a Wolf-Rayet progenitor. Our hydrodynamical modeling, on the contrary, indicates that the pre-explosion mass was relatively low, ?4 M {sub ?}. The seeming contradiction between a young age and low pre-SN mass may be solved by a massive interacting binary progenitor.

  8. H{sub ?} SPECTRAL DIVERSITY OF TYPE II SUPERNOVAE: CORRELATIONS WITH PHOTOMETRIC PROPERTIES

    SciTech Connect (OSTI)

    Gutirrez, Claudia P.; Hamuy, Mario; Gonzlez-Gaitn, Santiago [Millennium Institute of Astrophysics, Casilla 36-D, Santiago (Chile); Anderson, Joseph P. [Departamento de Astronoma, Universidad de Chile, Casilla 36-D, Santiago (Chile); Folatelli, Gastn [Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Morrell, Nidia I.; Phillips, Mark M.; Thomas-Osip, Joanna [Carnegie Observatories, Las Campanas Observatory, Casilla 601, La Serena (Chile); Stritzinger, Maximilian D. [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); McCarthy, Patrick [Observatories of the Carnegie Institution for Science, Pasadena, CA 91101 (United States); Suntzeff, Nicholas B., E-mail: cgutierr@das.uchile.cl [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States)

    2014-05-10

    We present a spectroscopic analysis of the H{sub ?} profiles of hydrogen-rich Type II supernovae. A total of 52 Type II supernovae having well-sampled optical light curves and spectral sequences were analyzed. Concentrating on the H{sub ?} P-Cygni profile we measure its velocity from the FWHM of the emission and the ratio of absorption to emission (a/e) at a common epoch at the start of the recombination phase, and search for correlations between these spectral parameters and photometric properties of the V-band light curves. Testing the strength of various correlations we find that a/e appears to be the dominant spectral parameter in terms of describing the diversity in our measured supernova properties. It is found that supernovae with smaller a/e have higher H{sub ?} velocities, more rapidly declining light curves from maximum during the plateau and radioactive tail phase, are brighter at maximum light, and have shorter optically thick phase durations. We discuss possible explanations of these results in terms of physical properties of Type II supernovae, speculating that the most likely parameters that influence the morphologies of H{sub ?} profiles are the mass and density profile of the hydrogen envelope, together with additional emission components due to circumstellar interaction.

  9. CfA4: LIGHT CURVES FOR 94 TYPE Ia SUPERNOVAE (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Authors: Hicken, Malcolm ; Challis, Peter ; Kirshner, Robert P. ; Bakos, Gaspar ; Berlind, Perry ; Brown, Warren R. ; Caldwell, Nelson ; Calkins, Mike ; Falco, Emilio ; Fernandez, ...

  10. CfA3: 185 TYPE Ia SUPERNOVA LIGHT CURVES FROM THE CfA (Journal...

    Office of Scientific and Technical Information (OSTI)

    Authors: Hicken, Malcolm ; Challis, Peter ; Kirshner, Robert P. ; Bakos, Gaspar ; Berlind, Perry ; Brown, Warren R. ; Caldwell, Nelson ; Calkins, Mike ; Cho, Richard ; Contreras, ...

  11. NEAR-ULTRAVIOLET PROPERTIES OF A LARGE SAMPLE OF TYPE Ia SUPERNOVAE...

    Office of Scientific and Technical Information (OSTI)

    Hicken, Malcolm ; Kirshner, Robert P. ; Challis, Peter J. 6 ; Mazzali, Paolo 7 ; Schmidt, Brian P. 8 + Show Author Affiliations Steward Observatory, University of Arizona, ...

  12. VARIABLE SODIUM ABSORPTION IN A LOW-EXTINCTION TYPE Ia SUPERNOVA...

    Office of Scientific and Technical Information (OSTI)

    We present the third detection of such variable absorption, based on six epochs of ... Country of Publication: United States Language: English Subject: 74 ATOMIC AND MOLECULAR ...

  13. Type Ia supernova rate measurements to redshift 2.5 from CANDELS...

    Office of Scientific and Technical Information (OSTI)

    Authors: Rodney, Steven A. ; Riess, Adam G. ; Graur, Or ; Jones, David O. 1 ; Strolger, Louis-Gregory ; Dahlen, Tomas ; Casertano, Stefano ; Ferguson, Henry C. ; Koekemoer, Anton ...

  14. Color dispersion and Milky-Way-like reddening among type Ia supernovae...

    Office of Scientific and Technical Information (OSTI)

    Authors: Scolnic, Daniel M. ; Riess, Adam G. ; Rodney, Steven A. ; Brout, Dillon J. ; Jones, David O. 1 ; Foley, Ryan J. 2 ; Rest, Armin 3 + Show Author Affiliations ...

  15. Type Ia supernovae from merging white dwarfs. II. Post-merger...

    Office of Scientific and Technical Information (OSTI)

    light curves rise and decline very slowly, and the spectra generally look peculiar, with weak features from intermediate mass elements but relatively strong carbon absorption. ...

  16. HIGH-VELOCITY LINE FORMING REGIONS IN THE TYPE Ia SUPERNOVA 2009ig...

    Office of Scientific and Technical Information (OSTI)

    TX 78712-0259 (United States) Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile) George P. and Cynthia Woods Mitchell Institute for Fundamental ...

  17. A SEARCH FOR NEW CANDIDATE SUPER-CHANDRASEKHAR-MASS TYPE Ia SUPERNOVAE...

    Office of Scientific and Technical Information (OSTI)

    Authors: Scalzo, R. 1 ; Aldering, G. ; Aragon, C. ; Bailey, S. ; Childress, M. ; Fakhouri, H. K. ; Hsiao, E. Y. 2 ; Antilogus, P. ; Bongard, S. ; Canto, A. ; Cellier-Holzem, F. ...

  18. Type Ia supernovae yielding distances with 3-4% precision (Journal...

    Office of Scientific and Technical Information (OSTI)

    dwarf stars, vary systematically with their intrinsic color and light-curve decline rate. ... two progenitor properties account for their light-curve-widthcolorluminosity relation. ...

  19. Hubble space telescope and ground-based observations of the type Iax supernovae SN 2005hk and SN 2008A

    SciTech Connect (OSTI)

    McCully, Curtis; Jha, Saurabh W. [Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Foley, Ryan J. [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States); Chornock, Ryan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Holtzman, Jon A. [Department of Astronomy, MSC 4500, New Mexico State University, P.O. Box 30001, Las Cruces, NM 88003 (United States); Balam, David D. [Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Branch, David [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States); Filippenko, Alexei V.; Ganeshalingam, Mohan; Li, Weidong [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Frieman, Joshua [Kavli Institute for Cosmological Physics and Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Fynbo, Johan; Leloudas, Giorgos [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Galbany, Lluis [Institut de Fsica d'Altes Energies, Universitat Autnoma de Barcelona, E-08193 Bellaterra (Barcelona) (Spain); Garnavich, Peter M. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Graham, Melissa L. [Las Cumbres Observatory Global Telescope Network, Goleta, CA 93117 (United States); Hsiao, Eric Y. [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Leonard, Douglas C., E-mail: cmccully@physics.rutgers.edu [Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States); and others

    2014-05-10

    We present Hubble Space Telescope (HST) and ground-based optical and near-infrared observations of SN 2005hk and SN 2008A, typical members of the Type Iax class of supernovae (SNe). Here we focus on late-time observations, where these objects deviate most dramatically from all other SN types. Instead of the dominant nebular emission lines that are observed in other SNe at late phases, spectra of SNe 2005hk and 2008A show lines of Fe II, Ca II, and Fe I more than a year past maximum light, along with narrow [Fe II] and [Ca II] emission. We use spectral features to constrain the temperature and density of the ejecta, and find high densities at late times, with n{sub e} ? 10{sup 9} cm{sup 3}. Such high densities should yield enhanced cooling of the ejecta, making these objects good candidates to observe the expected 'infrared catastrophe', a generic feature of SN Ia models. However, our HST photometry of SN 2008A does not match the predictions of an infrared catastrophe. Moreover, our HST observations rule out a 'complete deflagration' that fully disrupts the white dwarf for these peculiar SNe, showing no evidence for unburned material at late times. Deflagration explosion models that leave behind a bound remnant can match some of the observed properties of SNe Iax, but no published model is consistent with all of our observations of SNe 2005hk and 2008A.

  20. Characterizing the V-band light-curves of hydrogen-rich type II supernovae

    SciTech Connect (OSTI)

    Anderson, Joseph P.; González-Gaitán, Santiago; Hamuy, Mario; Gutiérrez, Claudia P.; Antezana, Roberto; De Jaeger, Thomas; Förster, Francisco; González, Luis; Stritzinger, Maximilian D.; Contreras, Carlos; Olivares E, Felipe; Phillips, Mark M.; Campillay, Abdo; Castellón, Sergio; Hsiao, Eric; Schulze, Steve; Bolt, Luis; Folatelli, Gastón; Freedman, Wendy L.; Krzemiński, Wojtek; and others

    2014-05-01

    We present an analysis of the diversity of V-band light-curves of hydrogen-rich type II supernovae. Analyzing a sample of 116 supernovae, several magnitude measurements are defined, together with decline rates at different epochs, and time durations of different phases. It is found that magnitudes measured at maximum light correlate more strongly with decline rates than those measured at other epochs: brighter supernovae at maximum generally have faster declining light-curves at all epochs. We find a relation between the decline rate during the 'plateau' phase and peak magnitudes, which has a dispersion of 0.56 mag, offering the prospect of using type II supernovae as purely photometric distance indicators. Our analysis suggests that the type II population spans a continuum from low-luminosity events which have flat light-curves during the 'plateau' stage, through to the brightest events which decline much faster. A large range in optically thick phase durations is observed, implying a range in progenitor envelope masses at the epoch of explosion. During the radioactive tails, we find many supernovae with faster declining light-curves than expected from full trapping of radioactive emission, implying low mass ejecta. It is suggested that the main driver of light-curve diversity is the extent of hydrogen envelopes retained before explosion. Finally, a new classification scheme is introduced where hydrogen-rich events are typed as simply 'SN II' with an 's {sub 2}' value giving the decline rate during the 'plateau' phase, indicating its morphological type.

  1. SUPERNOVA SIMULATIONS AND STRATEGIES FOR THE DARK ENERGY SURVEY

    SciTech Connect (OSTI)

    Bernstein, J. P.; Kuhlmann, S.; Biswas, R.; Kovacs, E.; Crane, I.; Hufford, T.; Kessler, R.; Frieman, J. A.; Aldering, G.; Kim, A. G.; Nugent, P.; D'Andrea, C. B.; Nichol, R. C.; Finley, D. A.; Marriner, J.; Reis, R. R. R.; Jarvis, M. J.; Mukherjee, P.; Parkinson, D.; Sako, M.; and others

    2012-07-10

    We present an analysis of supernova light curves simulated for the upcoming Dark Energy Survey (DES) supernova search. The simulations employ a code suite that generates and fits realistic light curves in order to obtain distance modulus/redshift pairs that are passed to a cosmology fitter. We investigated several different survey strategies including field selection, supernova selection biases, and photometric redshift measurements. Using the results of this study, we chose a 30 deg{sup 2} search area in the griz filter set. We forecast (1) that this survey will provide a homogeneous sample of up to 4000 Type Ia supernovae in the redshift range 0.05 supernova with an identified host galaxy will be obtained from spectroscopic observations of the host. A supernova spectrum will be obtained for a subset of the sample, which will be utilized for control studies. In addition, we have investigated the use of combined photometric redshifts taking into account data from both the host and supernova. We have investigated and estimated the likely contamination from core-collapse supernovae based on photometric identification, and have found that a Type Ia supernova sample purity of up to 98% is obtainable given specific assumptions. Furthermore, we present systematic uncertainties due to sample purity, photometric calibration, dust extinction priors, filter-centroid shifts, and inter-calibration. We conclude by estimating the uncertainty on the cosmological parameters that will be measured from the DES supernova data.

  2. Radio observations reveal a smooth circumstellar environment around the extraordinary type Ib supernova 2012au

    SciTech Connect (OSTI)

    Kamble, Atish; Soderberg, Alicia M.; Margutti, Raffaella; Milisavljevic, Dan; Chakraborti, Sayan; Dittmann, Jason; Drout, Maria; Sanders, Nathan; Chomiuk, Laura; Medvedev, Mikhail; Chevalier, Roger; Chugai, Nikolai; Fransson, Claes; Nakar, Ehud

    2014-12-10

    We present extensive radio and X-ray observations of SN 2012au, an energetic, radio-luminous supernova of Type Ib that exhibits multi-wavelength properties bridging subsets of hydrogen-poor superluminous supernovae, hypernovae, and normal core-collapse supernovae. The observations closely follow models of synchrotron emission from a shock-heated circumburst medium that has a wind density profile (??r {sup 2}). We infer a sub-relativistic velocity for the shock wave v ? 0.2 c and a radius of r ? 1.4 10{sup 16}cm at 25 days after the estimated date of explosion. For a wind velocity of 1000 km s{sup 1}, we determine the mass-loss rate of the progenitor to be M-dot =3.610{sup ?6} M{sub ?} yr{sup ?1}, consistent with the estimates from X-ray observations. We estimate the total internal energy of the radio-emitting material to be E ? 10{sup 47} erg, which is intermediate to SN 1998bw and SN 2002ap. The evolution of the radio light curve of SN 2012au is in agreement with its interaction with a smoothly distributed circumburst medium and the absence of stellar shells ejected from previous outbursts out to r ? 10{sup 17} cm from the supernova site. We conclude that the bright radio emission from SN 2012au was not dissimilar from other core-collapse supernovae despite its extraordinary optical properties, and that the evolution of the SN 2012au progenitor star was relatively quiet, marked with a steady mass loss, during the final years preceding explosion.

  3. Systematic Effects in Type-1a Supernovae Surveys from Host Galaxy...

    Office of Scientific and Technical Information (OSTI)

    of supernovae, and correlations between the progenitor stellar populations and the nature of the supernova light curves. Authors: Strauss, Michael A. 1 + Show Author...

  4. Systematic Effects in Type-1a Supernovae Surveys from Host Galaxy...

    Office of Scientific and Technical Information (OSTI)

    This grant found strong evidence for two distinct populations of supernovae, and correlations between the progenitor stellar populations and the nature of the supernova light ...

  5. Sloan Digital Sky Survey II (SDSS-II) Supernova Data

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    The Sloan Digital Sky Survey (SDSS) is a series of three interlocking imaging and spectroscopic surveys, carried out over an eight-year period with a dedicated 2.5m telescope located at Apache Point Observatory in Southern New Mexico. The SDSS Supernova Survey was one of those three components of SDSS and SDSS-II, a 3-year extension of the original SDSS that operated from July 2005 to July 2008. The Supernova Survey was a time-domain survey, involving repeat imaging of the same region of sky every other night, weather permitting. The primary scientific motivation was to detect and measure light curves for several hundred supernovae through repeat scans of the SDSS Southern equatorial stripe 82 (about 2.5? wide by ~120? long). Over the course of three 3-month campaigns SDSS-II SN discovered and measured multi-band lightcurves for ~500 spectroscopically confirmed Type Ia supernovae in the redshift range z=0.05-0.4. In addition, the project harvested a few hundred light curves for SNe Ia and discovered about 80 spectroscopically confirmed core-collapse supernovae (supernova types Ib/c and II).

  6. PTF 12gzkA rapidly declining, high-velocity type Ic radio supernova

    SciTech Connect (OSTI)

    Horesh, Assaf; Kulkarni, Shrinivas R.; Corsi, Alessandra; Frail, Dale A.; Cenko, S. Bradley; Ben-Ami, Sagi; Gal-Yam, Avishay; Yaron, Ofer; Arcavi, Iair; Ofek, Eran O.; Kasliwal, Mansi M.

    2013-11-20

    Only a few cases of Type Ic supernovae (SNe) with high-velocity ejecta (?0.2 c) have been discovered and studied. Here, we present our analysis of radio and X-ray observations of the Type Ic SN PTF 12gzk. The radio emission declined less than 10 days after explosion, suggesting SN ejecta expanding at high velocity (?0.3 c). The radio data also indicate that the density of the circumstellar material (CSM) around the supernova is lower by a factor of ?10 than the CSM around normal Type Ic SNe. PTF 12gzk may therefore be an intermediate event between a 'normal' SN Ic and a gamma-ray-burst-SN-like event. Our observations of this rapidly declining radio SN at a distance of 58 Mpc demonstrates the potential to detect many additional radio SNe, given the new capabilities of the Very Large Array (improved sensitivity and dynamic scheduling), which are currently missed, leading to a biased view of radio SNe Ic. Early optical discovery followed by rapid radio observations would provide a full description of the ejecta velocity distribution and CSM densities around stripped massive star explosions as well as strong clues about the nature of their progenitor stars.

  7. Study of Buoyancy-Driven Turbulent Nuclear Burning and Validation of Type

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ia Supernova Models | Argonne Leadership Computing Facility Four snapshots during a simulation of the explosion phase of the deflagration-to-detonation (DDT) model of nuclear-powered (Type Ia) supernovae. The images show extremely hot matter (ash or unburned fuel) and the surface of the star (green). Ignition of the nuclear flame was assumed to occur simultaneously at 63 points randomly distributed inside a 128-km sphere at the center of the white dwarf star. The images show volume

  8. RADIO OBSERVATIONS REVEAL UNUSUAL CIRCUMSTELLAR ENVIRONMENTS FOR SOME TYPE Ibc SUPERNOVA PROGENITORS

    SciTech Connect (OSTI)

    Wellons, Sarah; Soderberg, Alicia M.; Chevalier, Roger A.

    2012-06-10

    We present extensive radio observations of the nearby Type Ibc supernovae (SNe Ibc) 2004cc, 2004dk, and 2004gq spanning {Delta}t Almost-Equal-To 8-1900 days after explosion. Using a dynamical model developed for synchrotron emission from a slightly decelerated shock wave, we estimate the velocity and energy of the fastest ejecta and the density profile of the circumstellar medium. The shock waves of all three supernovae are characterized by non-relativistic velocities of v-bar approx. (0.1-25)c and associated energies of E Almost-Equal-To (2-10) Multiplication-Sign 10{sup 47} erg, in line with the expectations for a typical homologous explosion. Smooth circumstellar density profiles are indicated by the early radio data and we estimate the progenitor mass-loss rates to be M-dot approx. (0.6-13) x 10{sup -5} M{sub Sun} yr{sup -1} (wind velocity, v{sub w} = 10{sup 3} km s{sup -1}). These estimates approach the saturation limit ( M-dot {approx}10{sup -4} M{sub Sun} yr{sup -1}) for line-driven winds from Wolf-Rayet stars, the favored progenitors of SNe Ibc including those associated with long-duration gamma-ray bursts. Intriguingly, at later epochs all three supernovae show evidence for abrupt radio variability that we attribute to large density modulations (factor of {approx}3-6) at circumstellar radii of r Almost-Equal-To (1-50) Multiplication-Sign 10{sup 16} cm. If due to variable mass loss, these modulations are associated with progenitor activity on a timescale of {approx}10-100 years before explosion. We consider these results in the context of variable mass-loss mechanisms including wind clumping, metallicity-independent continuum-driven ejections, and binary-induced modulations. It may also be possible that the SN shock waves are dynamically interacting with wind termination shocks; however, this requires the environment to be highly pressurized and/or the progenitor to be rapidly rotating prior to explosion. The proximity of the density modulations to the

  9. First-Year Spectroscopy for the SDSS-II Supernova Survey

    SciTech Connect (OSTI)

    Zheng, Chen; Romani, Roger W.; Sako, Masao; Marriner, John; Bassett, Bruce; Becker, Andrew; Choi, Changsu; Cinabro, David; DeJongh, Fritz; Depoy, Darren L.; Dilday, Ben; Doi, Mamoru; Frieman, Joshua A.; Garnavich, Peter M.; Hogan, Craig J.; Holtzman, Jon; Im, Myungshin; Jha, Saurabh; Kessler, Richard; Konishi, Kohki; Lampeitl, Hubert

    2008-03-25

    This paper presents spectroscopy of supernovae discovered in the first season of the Sloan Digital Sky Survey-II Supernova Survey. This program searches for and measures multi-band light curves of supernovae in the redshift range z = 0.05-0.4, complementing existing surveys at lower and higher redshifts. Our goal is to better characterize the supernova population, with a particular focus on SNe Ia, improving their utility as cosmological distance indicators and as probes of dark energy. Our supernova spectroscopy program features rapid-response observations using telescopes of a range of apertures, and provides confirmation of the supernova and host-galaxy types as well as precise redshifts. We describe here the target identification and prioritization, data reduction, redshift measurement, and classification of 129 SNe Ia, 16 spectroscopically probable SNe Ia, 7 SNe Ib/c, and 11 SNe II from the first season. We also describe our efforts to measure and remove the substantial host galaxy contamination existing in the majority of our SN spectra.

  10. Stellar Evolution/Supernova Research Data Archives from the SciDAC Computational Astrophysics Consortium

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Woosley, Stan [University of California, Santa Cruz

    Theoretical high-energy astrophysics studies the most violent explosions in the universe - supernovae (the massive explosions of dying stars) and gamma ray bursts (mysterious blasts of intense radiation). The evolution of massive stars and their explosion as supernovae and/or gamma ray bursts describes how the "heavy" elements needed for life, such as oxygen and iron, are forged (nucleosynthesis) and ejected to later form new stars and planets. The Computational Astrophysics Consortium's project includes a Science Application Partnership on Adaptive Algorithms that develops software involved. The principal science topics are - in order of priority - 1) models for Type Ia supernovae, 2) radiation transport, spectrum formation, and nucleosynthesis in model supernovae of all types; 3) the observational implications of these results for experiments in which DOE has an interest, especially the Joint Dark Energy Mission, Supernova/Acceleration Probe (SNAP) satellite observatory, the Large Synoptic Survey Telescope (LSST), and ground based supernova searches; 4) core collapse supernovae; 5) gamma-ray bursts; 6) hypernovae from Population III stars; and 7) x-ray bursts. Models of these phenomena share a common need for nuclear reactions and radiation transport coupled to multi-dimensional fluid flow. The team has developed and used supernovae simulation codes to study Type 1A and core-collapse supernovae. (Taken from http://www.scidac.gov/physics/grb.html) The Stellar Evolution Data Archives contains more than 225 Pre-SN models that can be freely accessed.

  11. LATE-TIME DUST EMISSION FROM THE TYPE IIn SUPERNOVA 1995N

    SciTech Connect (OSTI)

    Van Dyk, Schuyler D.

    2013-05-15

    Type IIn supernovae (SNe IIn) have been found to be associated with significant amounts of dust. These core-collapse events are generally expected to be the final stage in the evolution of highly massive stars, either while in an extreme red supergiant phase or during a luminous blue variable phase. Both evolutionary scenarios involve substantial pre-supernova mass loss. I have analyzed the SN IIn 1995N in MCG -02-38-017 (Arp 261), for which mid-infrared archival data obtained with the Spitzer Space Telescope in 2009 ({approx}14.7 yr after explosion) and with the Wide-field Infrared Survey Explorer in 2010 ({approx}15.6-16.0 yr after explosion) reveal a luminous ({approx}2 Multiplication-Sign 10{sup 7} L{sub Sun }) source detected from 3.4 to 24 {mu}m. These observations probe the circumstellar material, set up by pre-SN mass loss, around the progenitor star and indicate the presence of {approx}0.05-0.12 M{sub Sun} of pre-existing, cool dust at {approx}240 K. This is at least a factor {approx}10 lower than the dust mass required to be produced from SNe at high redshift, but the case of SN 1995N lends further evidence that highly massive stars could themselves be important sources of dust.

  12. Type IIP supernovae as cosmological probes: A SEAM distance to SN1999em

    SciTech Connect (OSTI)

    Baron, E.; Nugent, Peter E.; Branch, David; Hauschildt, Peter H.

    2004-06-01

    Because of their intrinsic brightness, supernovae make excellent cosmological probes. We describe the spectral-fitting expanding atmosphere method (SEAM) for obtaining distances to Type IIP supernovae (SNe IIP) and present a distance to SN 1999em for which a Cepheid distance exists. Our models give results consistent with the Cepheid distance, even though we have not attempted to tune the underlying hydrodynamical model but have simply chosen the best fits. This is in contradistinction to the expanding photosphere method (EPM), which yields a distance to SN 1999em that is 50 percent smaller than the Cepheid distance. We emphasize the differences between the SEAM and the EPM. We show that the dilution factors used in the EPM analysis were systematically too small at later epochs. We also show that the EPM blackbody assumption is suspect. Since SNe IIP are visible to redshifts as high as z {approx}< 6, with the James Webb Space Telescope, the SEAM may be a valuable probe of the early universe.

  13. THE BIRTH RATE OF SNe Ia FROM HYBRID CONe WHITE DWARFS

    SciTech Connect (OSTI)

    Meng, Xiangcun [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Podsiadlowski, Philipp, E-mail: xiangcunmeng@ynao.ac.cn [Department of Astronomy, Oxford University, Oxford OX1 3RH (United Kingdom)

    2014-07-10

    Considering the uncertainties of the C-burning rate (CBR) and the treatment of convective boundaries, Chen et al. found that there is a regime where it is possible to form hybrid CONe white dwarfs (WDs), i.e., ONe WDs with carbon-rich cores. As these hybrid WDs can be as massive as 1.30 M {sub ?}, not much mass needs to be accreted for these objects to reach the Chandrasekhar limit and to explode as Type Ia supernovae (SNe Ia). We have investigated their contribution to the overall SN Ia birth rate and found that such SNe Ia tend to be relatively young with typical time delays between 0.1 and 1 Gyr, where some may be as young as 30 Myr. SNe Ia from hybrid CONe WDs may contribute several percent to all SNe Ia, depending on the common-envelope ejection efficiency and the CBR. We suggest that these SNe Ia may produce part of the 2002cx-like SN Ia class.

  14. FUZZY SUPERNOVA TEMPLATES. I. CLASSIFICATION

    SciTech Connect (OSTI)

    Rodney, Steven A.; Tonry, John L. E-mail: jt@ifa.hawaii.ed

    2009-12-20

    Modern supernova (SN) surveys are now uncovering stellar explosions at rates that far surpass what the world's spectroscopic resources can handle. In order to make full use of these SN data sets, it is necessary to use analysis methods that depend only on the survey photometry. This paper presents two methods for utilizing a set of SN light-curve templates to classify SN objects. In the first case, we present an updated version of the Bayesian Adaptive Template Matching program (BATM). To address some shortcomings of that strictly Bayesian approach, we introduce a method for Supernova Ontology with Fuzzy Templates (SOFT), which utilizes fuzzy set theory for the definition and combination of SN light-curve models. For well-sampled light curves with a modest signal-to-noise ratio (S/N >10), the SOFT method can correctly separate thermonuclear (Type Ia) SNe from core collapse SNe with >=98% accuracy. In addition, the SOFT method has the potential to classify SNe into sub-types, providing photometric identification of very rare or peculiar explosions. The accuracy and precision of the SOFT method are verified using Monte Carlo simulations as well as real SN light curves from the Sloan Digital Sky Survey and the SuperNova Legacy Survey. In a subsequent paper, the SOFT method is extended to address the problem of parameter estimation, providing estimates of redshift, distance, and host galaxy extinction without any spectroscopy.

  15. CAN STELLAR MIXING EXPLAIN THE LACK OF TYPE Ib SUPERNOVAE IN LONG-DURATION GAMMA-RAY BURSTS?

    SciTech Connect (OSTI)

    Frey, Lucille H. [HPC-3, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Fryer, Chris L. [CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Young, Patrick A. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85276 (United States)

    2013-08-10

    The discovery of supernovae associated with long-duration gamma-ray burst observations is primary evidence that the progenitors of these outbursts are massive stars. One of the principle mysteries in understanding these progenitors has been the fact that all of these gamma-ray-burst-associated supernovae are Type Ic supernovae with no evidence of helium in the stellar atmosphere. Many studies have focused on whether or not this helium is simply hidden from spectral analyses. In this Letter, we show results from recent stellar models using new convection algorithms based on our current understanding of stellar mixing. We demonstrate that enhanced convection may lead to severe depletion of stellar helium layers, suggesting that the helium is not observed simply because it is not in the star. We also present light curves and spectra of these compact helium-depleted stars compared to models with more conventional helium layers.

  16. The Sloan Digital Sky Survey-II Supernova Survey: Technical Summary

    SciTech Connect (OSTI)

    Frieman, Joshua A.; Bassett, Bruce; Becker, Andrew; Choi, Changsu; Cinabro, David; DeJongh, Don Frederic; Depoy, Darren L.; Doi, Mamoru; Garnavich, Peter M.; Hogan, Craig J.; Holtzman, Jon; Im, Myungshin; Jha, Saurabh; Konishi, Kohki; Lampeitl, Hubert; Marriner, John; Marshall, Jennifer L.; McGinnis, David; Miknaitis, Gajus; Nichol, Robert C.; Prieto, Jose Luis; /Ohio State U. /Rochester Inst. Tech. /Stanford U., Phys. Dept. /Pennsylvania U. /Penn State U., Astron. Astrophys. /Portsmouth U. /Tokyo U. /Tokyo U. /South African Astron. Observ. /Tokyo U. /Stanford U., Phys. Dept. /Fermilab /Fermilab /Ohio State U. /Stanford U., Phys. Dept. /Fermilab /Bristol U. /Apache Point Observ. /Liverpool John Moores U., ARI /Columbia U., CBA /Apache Point Observ. /Ohio State U. /Durham U. /Portsmouth U. /South African Astron. Observ. /Naval Academy, Annapolis /UC, Berkeley /UC, Berkeley /Ohio State U. /Stockholm U. /New Mexico State U. /Princeton U. Observ. /Tokyo U. /Washington U., Seattle, Astron. Dept. /Stanford U., Phys. Dept. /Jefferson Lab /Apache Point Observ. /Gottingen U. /Chicago U. /San Francisco State U. /DARK Cosmology Ctr. /Fermilab /Apache Point Observ. /Durham U. /Princeton U. Observ. /Apache Point Observ. /Apache Point Observ. /Apache Point Observ. /Barcelona U. /Stockholm U. /Apache Point Observ. /Lick Observ. /Sussex U. /Barcelona U. /Apache Point Observ. /Ohio State U. /Apache Point Observ. /Fermilab /DARK Cosmology Ctr. /Chicago U. /Fermilab /South African Astron. Observ. /Ohio State U. /Apache Point Observ. /Texas U., McDonald Observ. /Fermilab

    2007-09-14

    The Sloan Digital Sky Survey-II (SDSS-II) has embarked on a multi-year project to identify and measure light curves for intermediate-redshift (0.05 < z < 0.35) Type Ia supernovae (SNe Ia) using repeated five-band (ugriz) imaging over an area of 300 sq. deg. The survey region is a stripe 2.5 degrees wide centered on the celestial equator in the Southern Galactic Cap that has been imaged numerous times in earlier years, enabling construction of a deep reference image for discovery of new objects. Supernova imaging observations are being acquired between 1 September and 30 November of 2005-7. During the first two seasons, each region was imaged on average every five nights. Spectroscopic follow-up observations to determine supernova type and redshift are carried out on a large number of telescopes. In its first two three-month seasons, the survey has discovered and measured light curves for 327 spectroscopically confirmed SNe Ia, 30 probable SNe Ia, 14 confirmed SNe Ib/c, 32 confirmed SNe II, plus a large number of photometrically identified SNe Ia, 94 of which have host-galaxy spectra taken so far. This paper provides an overview of the project and briefly describes the observations completed during the first two seasons of operation.

  17. Characterizing mid-ultraviolet to optical light curves of nearby type IIn supernovae

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    de la Rosa, Janie; Roming, Pete; Pritchard, Tyler; Fryer, Chris

    2016-03-21

    Here, we present early mid-ultraviolet and optical observations of Type IIn supernovae (SNe IIn) observed from 2007 to 2013. Our results focus on the properties of UV light curves: peak absolute magnitudes, temporal decay, and color evolution. During early times, this sample demonstrates that UV light decays faster than optical, and each event transitions from a predominantly UV-bright phase to an optically bright phase. In order to understand early UV behavior, we generate and analyze the sample's blackbody luminosity, temperature, and radius as the SN ejecta expand and cool. Since most of our observations were detected post maximum luminosity, wemore » introduce a method for estimating the date of peak magnitude. When our observations are compared based on filter, we find that even though these SNe IIn vary in peak magnitudes, there are similarities in UV decay rates. We use a simple semi-analytical SN model in order to understand the effects of the explosion environment on our UV observations. Understanding the UV characteristics of nearby SNe IIn during an early phase can provide valuable information about the environment surrounding these explosions, leading us to evaluating the diversity of observational properties in this subclass.« less

  18. Precursors prior to type IIn supernova explosions are common: Precursor rates, properties, and correlations

    SciTech Connect (OSTI)

    Ofek, Eran O.; Steinbok, Aviram; Arcavi, Iair; Gal-Yam, Avishay; Tal, David; Ben-Ami, Sagi; Yaron, Ofer; Sullivan, Mark; Shaviv, Nir J.; Kulkarni, Shrinivas R.; Nugent, Peter E.; Kasliwal, Mansi M.; Cenko, S. Bradley; Silverman, Jeffrey M.

    2014-07-10

    There is a growing number of Type IIn supernovae (SNe) which present an outburst prior to their presumably final explosion. These precursors may affect the SN display, and are likely related to poorly charted phenomena in the final stages of stellar evolution. By coadding Palomar Transient Factory (PTF) images taken prior to the explosion, here we present a search for precursors in a sample of 16 Type IIn SNe. We find five SNe IIn that likely have at least one possible precursor event (PTF 10bjb, SN 2010mc, PTF 10weh, SN 2011ht, and PTF 12cxj), three of which are reported here for the first time. For each SN we calculate the control time. We find that precursor events among SNe IIn are common: at the one-sided 99% confidence level, >50% of SNe IIn have at least one pre-explosion outburst that is brighter than 3 × 10{sup 7} L{sub ☉} taking place up to 1/3 yr prior to the SN explosion. The average rate of such precursor events during the year prior to the SN explosion is likely ≳ 1 yr{sup –1}, and fainter precursors are possibly even more common. Ignoring the two weakest precursors in our sample, the precursors rate we find is still on the order of one per year. We also find possible correlations between the integrated luminosity of the precursor and the SN total radiated energy, peak luminosity, and rise time. These correlations are expected if the precursors are mass-ejection events, and the early-time light curve of these SNe is powered by interaction of the SN shock and ejecta with optically thick circumstellar material.

  19. Optical observations of the type Ic supernova 2007gr in NGC 1058

    SciTech Connect (OSTI)

    Chen, Juncheng; Wang, Xiaofeng; Li, Junzheng; Ganeshalingam, Mohan; Silverman, Jeffrey M.; Filippenko, Alexei V.; Li, Weidong; Chornock, Ryan; Steele, Thea E-mail: wang_xf@mail.tsinghua.edu.cn

    2014-08-01

    We present extensive optical observations of the normal Type Ic supernova (SN) 2007gr, spanning from about one week before maximum light to more than one year thereafter. The optical light and color curves of SN 2007gr are very similar to those of the broad-lined Type Ic SN 2002ap, but the spectra show remarkable differences. The optical spectra of SN 2007gr are characterized by unusually narrow lines, prominent carbon lines, and slow evolution of the line velocity after maximum light. The earliest spectrum (taken at t = –8 days) shows a possible signature of helium (He I λ5876 at a velocity of ∼19,000 km s{sup –1}). Moreover, the larger intensity ratio of the [O I] λ6300 and λ6364 lines inferred from the early nebular spectra implies a lower opacity of the ejecta shortly after the explosion. These results indicate that SN 2007gr perhaps underwent a less energetic explosion of a smaller-mass Wolf-Rayet star (∼8-9 M{sub ☉}) in a binary system, as favored by an analysis of the progenitor environment through pre-explosion and post-explosion Hubble Space Telescope images. In the nebular spectra, asymmetric double-peaked profiles can be seen in the [O I] λ6300 and Mg I] λ4571 lines. We suggest that the two peaks are contributed by the blueshifted and rest-frame components. The similarity in velocity structure and the different evolution of the strength of the two components favor an aspherical explosion with the ejecta distributed in a torus or disk-like geometry, but inside the ejecta the O and Mg have different distributions.

  20. SUPER-LUMINOUS TYPE Ic SUPERNOVAE: CATCHING A MAGNETAR BY THE TAIL

    SciTech Connect (OSTI)

    Inserra, C.; Smartt, S. J.; Jerkstrand, A.; Fraser, M.; Wright, D.; Smith, K.; Chen, T.-W.; Kotak, R.; Nicholl, M.; Valenti, S.; Pastorello, A.; Benetti, S.; Bresolin, F.; Kudritzki, R. P.; Burgett, W. S.; Chambers, K. C.; Flewelling, H.; Botticella, M. T.; Ergon, M.; Fynbo, J. P. U.; and others

    2013-06-20

    We report extensive observational data for five of the lowest redshift Super-Luminous Type Ic Supernovae (SL-SNe Ic) discovered to date, namely, PTF10hgi, SN2011ke, PTF11rks, SN2011kf, and SN2012il. Photometric imaging of the transients at +50 to +230 days after peak combined with host galaxy subtraction reveals a luminous tail phase for four of these SL-SNe. A high-resolution, optical, and near-infrared spectrum from xshooter provides detection of a broad He I {lambda}10830 emission line in the spectrum (+50 days) of SN2012il, revealing that at least some SL-SNe Ic are not completely helium-free. At first sight, the tail luminosity decline rates that we measure are consistent with the radioactive decay of {sup 56}Co, and would require 1-4 M{sub Sun} of {sup 56}Ni to produce the luminosity. These {sup 56}Ni masses cannot be made consistent with the short diffusion times at peak, and indeed are insufficient to power the peak luminosity. We instead favor energy deposition by newborn magnetars as the power source for these objects. A semi-analytical diffusion model with energy input from the spin-down of a magnetar reproduces the extensive light curve data well. The model predictions of ejecta velocities and temperatures which are required are in reasonable agreement with those determined from our observations. We derive magnetar energies of 0.4 {approx}< E(10{sup 51} erg) {approx}< 6.9 and ejecta masses of 2.3 {approx}< M{sub ej}(M{sub Sun }) {approx}< 8.6. The sample of five SL-SNe Ic presented here, combined with SN 2010gx-the best sampled SL-SNe Ic so far-points toward an explosion driven by a magnetar as a viable explanation for all SL-SNe Ic.

  1. SWIFT/BAT DETECTION OF HARD X-RAYS FROM TYCHO'S SUPERNOVA REMNANT: EVIDENCE FOR TITANIUM-44

    SciTech Connect (OSTI)

    Troja, E.; Baumgartner, W.; Markwardt, C.; Barthelmy, S.; Gehrels, N.; Segreto, A.; La Parola, V.; Cusumano, G.; Hartmann, D.

    2014-12-10

    We report Swift/Burst Alert Telescope survey observations of the Tycho's supernova remnant, performed over a period of 104 months since the mission's launch. The remnant is detected with high significance (>10σ) below 50 keV. We detect significant hard X-ray emission in the 60-85 keV band, above the continuum level predicted by a simple synchrotron model. The location of the observed excess is consistent with line emission from radioactive titanium-44, so far reported only for Type II supernova explosions. We discuss the implications of these results in the context of the galactic supernova rate, and nucleosynthesis in Type Ia supernova.

  2. Stellar Evolution/Supernova Research Data Archives from the SciDAC...

    Office of Scientific and Technical Information (OSTI)

    and ground based supernova searches; 4) core collapse supernovae; 5) gamma-ray bursts; ... codes to study Type 1Amore and core-collapse supernovae. (Taken from http:...

  3. MULTI-WAVELENGTH OBSERVATIONS OF SUPERNOVA 2011ei: TIME-DEPENDENT CLASSIFICATION OF TYPE IIb AND Ib SUPERNOVAE AND IMPLICATIONS FOR THEIR PROGENITORS

    SciTech Connect (OSTI)

    Milisavljevic, Dan; Margutti, Raffaella; Soderberg, Alicia M.; Chomiuk, Laura; Sanders, Nathan E.; Pignata, Giuliano; Bufano, Filomena; Fesen, Robert A.; Parrent, Jerod T.; Parker, Stuart; Mazzali, Paolo; Pian, Elena; Pickering, Timothy; Buckley, David A. H.; Crawford, Steven M.; Gulbis, Amanda A. S.; Hettlage, Christian; Hooper, Eric; Nordsieck, Kenneth H.; O'Donoghue, Darragh; and others

    2013-04-10

    We present X-ray, UV/optical, and radio observations of the stripped-envelope, core-collapse supernova (SN) 2011ei, one of the least luminous SNe IIb or Ib observed to date. Our observations begin with a discovery within {approx}1 day of explosion and span several months afterward. Early optical spectra exhibit broad, Type II-like hydrogen Balmer profiles that subside rapidly and are replaced by Type Ib-like He-rich features on a timescale of one week. High-cadence monitoring of this transition suggests absorption attributable to a high-velocity ({approx}> 12, 000 km s{sup -1}) H-rich shell, which is likely present in many Type Ib events. Radio observations imply a shock velocity of v Almost-Equal-To 0.13 c and a progenitor star average mass-loss rate of M-dot {approx}1.4 Multiplication-Sign 10{sup -5} M{sub sun} yr{sup -1} (assuming wind velocity v{sub w} = 10{sup 3} km s{sup -1}). This is consistent with independent constraints from deep X-ray observations with Swift-XRT and Chandra. Overall, the multi-wavelength properties of SN 2011ei are consistent with the explosion of a lower-mass (3-4 M{sub Sun }), compact (R{sub *} {approx}< 1 Multiplication-Sign 10{sup 11} cm), He-core star. The star retained a thin hydrogen envelope at the time of explosion, and was embedded in an inhomogeneous circumstellar wind suggestive of modest episodic mass loss. We conclude that SN 2011ei's rapid spectral metamorphosis is indicative of time-dependent classifications that bias estimates of the relative explosion rates for Type IIb and Ib objects, and that important information about a progenitor star's evolutionary state and mass loss immediately prior to SN explosion can be inferred from timely multi-wavelength observations.

  4. TYPE IIn SUPERNOVA SN 2010jl: OPTICAL OBSERVATIONS FOR OVER 500 DAYS AFTER EXPLOSION

    SciTech Connect (OSTI)

    Zhang Tianmeng; Wu Chao; Zhai Meng; Wu Hong; Fan Zhou; Zou Hu; Zhou Xu; Ma Jun; Wang Xiaofeng; Chen Juncheng; Chen Jia; Liu Qin; Huang Fang; Liang Jide; Zhao Xulin; Lin Lin; Wang Min; Dennefeld, Michel; Zhang Jujia E-mail: wang_xf@mail.tsinghua.edu.cn

    2012-11-01

    We present extensive optical observations of a Type IIn supernova (SN IIn) 2010jl for the first 1.5 years after its discovery. The UBVRI light curves demonstrated an interesting two-stage evolution during the nebular phase, which almost flatten out after about 90 days from the optical maximum. SN 2010jl has one of the highest intrinsic H{alpha} luminosities ever recorded for an SN IIn, especially at late phase, suggesting a strong interaction of SN ejecta with the dense circumstellar material (CSM) ejected by the progenitor. This is also indicated by the remarkably strong Balmer lines persisting in the optical spectra. One interesting spectral evolution about SN 2010jl is the appearance of asymmetry of the Balmer lines. These lines can be well decomposed into a narrow component and an intermediate-width component. The intermediate-width component showed a steady increase in both strength and blueshift with time until t {approx} 400 days after maximum, but it became less blueshifted at t {approx} 500 days, when the line profile appeared relatively symmetric again. Owing to the fact that a pure reddening effect will lead to a sudden decline of the light curves and a progressive blueshift of the spectral lines, we therefore propose that the asymmetric profiles of H lines seen in SN 2010jl are unlikely due to the extinction by newly formed dust inside the ejecta, contrary to the explanation by some early studies. Based on a simple CSM-interaction model, we speculate that the progenitor of SN 2010jl may suffer a gigantic mass loss ({approx}30-50 M{sub Sun }) a few decades before explosion. Considering a slow-moving stellar wind (e.g., {approx}28 km s{sup -1}) inferred for the preexisting, dense CSM shell and the extremely high mass-loss rate (1-2 M{sub Sun} yr{sup -1}), we suggest that the progenitor of SN 2010jl might have experienced a red supergiant stage and may explode finally as a post-red supergiant star with an initial mass above 30-40 M{sub Sun }.

  5. SPECTRAL IDENTIFICATION OF AN ANCIENT SUPERNOVA USING LIGHT ECHOES IN THE LMC

    SciTech Connect (OSTI)

    Rest, A; Matheson, T; Blondin, S; Bergmann, M; Welch, D L; Suntzeff, N B; Smith, R C; Olsen, K; Prieto, J L; Garg, A; Challis, P; Stubbs, C; Hicken, M; Modjaz, M; Wood-Vasey, W M; Zenteno, A; Damke, G; Newman, A; Huber, M; Cook, K H; Nikolaev, S; Becker, A C; Miceli, A; Covarrubias, R; Morelli, L; Pignata, G; Clocchiatti, A; Minniti, D; Foley, R J

    2008-02-07

    We report the successful identification of the type of the supernova responsible for the supernova remnant SNR 0509-675 in the Large Magellanic Cloud (LMC) using Gemini spectra of surrounding light echoes. The ability to classify outbursts associated with centuries-old remnants provides a new window into several aspects of supernova research and is likely to be successful in providing new constraints on additional LMC supernovae as well as their historical counterparts in the Milky Way Galaxy (MWG). The combined spectrum of echo light from SNR 0509-675 shows broad emission and absorption lines consistent with a supernova (SN) spectrum. We create a spectral library consisting of 26 SNe Ia and 6 SN Ib/c that are time-integrated, dust-scattered by LMC dust, and reddened by the LMC and MWG. We fit these SN templates to the observed light echo spectrum using {chi}{sup 2} minimization as well as correlation techniques, and we find that overluminous 91T-like SNe Ia with {Delta}m{sub 15} < 0.9 match the observed spectrum best.

  6. FUZZY SUPERNOVA TEMPLATES. II. PARAMETER ESTIMATION

    SciTech Connect (OSTI)

    Rodney, Steven A.; Tonry, John L. E-mail: jt@ifa.hawaii.ed

    2010-05-20

    Wide-field surveys will soon be discovering Type Ia supernovae (SNe) at rates of several thousand per year. Spectroscopic follow-up can only scratch the surface for such enormous samples, so these extensive data sets will only be useful to the extent that they can be characterized by the survey photometry alone. In a companion paper we introduced the Supernova Ontology with Fuzzy Templates (SOFT) method for analyzing SNe using direct comparison to template light curves, and demonstrated its application for photometric SN classification. In this work we extend the SOFT method to derive estimates of redshift and luminosity distance for Type Ia SNe, using light curves from the Sloan Digital Sky Survey (SDSS) and Supernova Legacy Survey (SNLS) as a validation set. Redshifts determined by SOFT using light curves alone are consistent with spectroscopic redshifts, showing an rms scatter in the residuals of rms{sub z} = 0.051. SOFT can also derive simultaneous redshift and distance estimates, yielding results that are consistent with the currently favored {Lambda}CDM cosmological model. When SOFT is given spectroscopic information for SN classification and redshift priors, the rms scatter in Hubble diagram residuals is 0.18 mag for the SDSS data and 0.28 mag for the SNLS objects. Without access to any spectroscopic information, and even without any redshift priors from host galaxy photometry, SOFT can still measure reliable redshifts and distances, with an increase in the Hubble residuals to 0.37 mag for the combined SDSS and SNLS data set. Using Monte Carlo simulations, we predict that SOFT will be able to improve constraints on time-variable dark energy models by a factor of 2-3 with each new generation of large-scale SN surveys.

  7. Critical study of type II supernovae: equations of state and general relativity

    SciTech Connect (OSTI)

    Kahana, S.

    1986-01-01

    The relevance of relativistic gravitation and of the properties of nuclear matter at high density to supernova explosions is examined in detail. The existing empirical knowledge on the nuclear equation of state at densities greater than saturation, extracted from analysis of heavy ion collisions and from the breathing mode in heavy nuclei, is also considered. Particulars of the prompt explosions recently obtained theoretically by Baron, Cooperstein, and Kahana are presented. 40 refs., 9 figs., 3 tabs.

  8. SLOW-SPEED SUPERNOVAE FROM THE PALOMAR TRANSIENT FACTORY: TWO CHANNELS

    SciTech Connect (OSTI)

    White, Christopher J.; Kasliwal, Mansi M.; Piro, Anthony L.; Nugent, Peter E.; Gal-Yam, Avishay; Ofek, Eran O.; Ben-Ami, Sagi; Howell, D. Andrew; Sullivan, Mark; Goobar, Ariel; Bloom, Joshua S.; Kulkarni, Shrinivas R.; Cao, Yi; Laher, Russ R.; Masci, Frank; Surace, Jason; Hook, Isobel M.; Jönsson, Jakob; Matheson, Thomas; and others

    2015-01-20

    Since the discovery of the unusual prototype SN 2002cx, the eponymous class of Type I (hydrogen-poor) supernovae with low ejecta speeds has grown to include approximately two dozen members identified from several heterogeneous surveys, in some cases ambiguously. Here we present the results of a systematic study of 1077 Type I supernovae discovered by the Palomar Transient Factory, leading to nine new members of this peculiar class. Moreover, we find there are two distinct subclasses based on their spectroscopic, photometric, and host galaxy properties: ''SN 2002cx-like'' supernovae tend to be in later-type or more irregular hosts, have more varied and generally dimmer luminosities, have longer rise times, and lack a Ti II trough when compared to ''SN 2002es-like'' supernovae. None of our objects show helium, and we counter a previous claim of two such events. We also find that the occurrence rate of these transients relative to Type Ia supernovae is 5.6{sub −3.8}{sup +22}% (90% confidence), lower compared to earlier estimates. Combining our objects with the literature sample, we propose that these subclasses have two distinct physical origins.

  9. Photon-axion conversion as a mechanism for supernova dimming: Limits from CMB spectral distortion

    SciTech Connect (OSTI)

    Mirizzi, Alessandro; Raffelt, Georg G.; Serpico, Pasquale D.

    2005-07-15

    Axion-photon conversion induced by intergalactic magnetic fields has been proposed as an explanation for the dimming of distant supernovae of type Ia (SNe Ia) without cosmic acceleration. The effect depends on the intergalactic electron density n{sub e} as well as the B-field strength and domain size. We show that for n{sub e} < or approx. 10{sup -9} cm{sup -3} the same mechanism would cause excessive spectral distortion of the cosmic microwave background (CMB). This small-n{sub e} parameter region had been left open by the most restrictive previous constraints based on the dispersion of quasar (QSO) spectra. The combination of CMB and QSO limits suggests that the photon-axion conversion mechanism can only play a subleading role for SN Ia dimming. A combined analysis of all the observables affected by the photon-axion oscillations would be required to give a final verdict on the viability of this model.

  10. SNe Ia tests of quintessence tracker cosmology in an anisotropic background

    SciTech Connect (OSTI)

    Miranda, W.; Carneiro, S.; Pigozzo, C. E-mail: saulo.carneiro@pq.cnpq.br

    2014-07-01

    We investigate the observational effects of a quintessence model in an anisotropic spacetime. The anisotropic metric is a non-rotating particular case of a generalized Gödel's metric and is classified as Bianchi III. This metric is an exact solution of the Einstein-Klein-Gordon field equations with an anisotropic scalar field ψ, which is responsible for the anisotropy of the spacetime geometry. We test the model against observations of type Ia supernovae, analyzing the SDSS dataset calibrated with the MLCS2k2 fitter, and the results are compared to standard quintessence models with Ratra-Peebles potentials. We obtain a good agreement with observations, with best values for the matter and curvature density parameters Ω{sub M} = 0.29 and Ω{sub k}= 0.01 respectively. We conclude that present SNe Ia observations cannot, alone, distinguish a possible anisotropic axis in the cosmos.

  11. iPTF13bvn: The first evidence of a binary progenitor for a type Ib supernova

    SciTech Connect (OSTI)

    Bersten, Melina C.; Folatelli, Gastn; Nomoto, Ken'ichi; Quimby, Robert; Benvenuto, Omar G.; Srivastav, Shubham; Anupama, G. C.; Sahu, Devendra K.

    2014-10-01

    The recent detection in archival Hubble Space Telescope images of an object at the location of supernova (SN) iPTF13bvn may represent the first direct evidence of the progenitor of a Type Ib SN. The object's photometry was found to be compatible with a Wolf-Rayet pre-SN star mass of ?11 M {sub ?}. However, based on hydrodynamical models, we show that the progenitor had a pre-SN mass of ?3.5 M {sub ?} and that it could not be larger than ?8 M {sub ?}. We propose an interacting binary system as the SN progenitor and perform evolutionary calculations that are able to self-consistently explain the light curve shape, the absence of hydrogen, and the pre-SN photometry. We further discuss the range of allowed binary systems and predict that the remaining companion is a luminous O-type star of significantly lower flux in the optical than the pre-SN object. A future detection of such a star may be possible and would provide the first robust identification of a progenitor system for a Type Ib SN.

  12. The type IIP supernova 2012aw in M95: Hydrodynamical modeling of the photospheric phase from accurate spectrophotometric monitoring

    SciTech Connect (OSTI)

    Dall'Ora, M.; Botticella, M. T.; Della Valle, M. [INAF, Osservatorio Astronomico di Capodimonte, Napoli (Italy); Pumo, M. L.; Zampieri, L.; Tomasella, L.; Cappellaro, E.; Benetti, S. [INAF, Osservatorio Astronomico di Padova, I-35122 Padova (Italy); Pignata, G.; Bufano, F. [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile); Bayless, A. J. [Southwest Research Institute, Department of Space Science, 6220 Culebra Road, San Antonio, TX 78238 (United States); Pritchard, T. A. [Department of Astronomy and Astrophysics, Penn State University, 525 Davey Lab, University Park, PA 16802 (United States); Taubenberger, S.; Benitez, S. [Max-Planck-Institut fr Astrophysik, Karl-Schwarzschild-Str. 1, D-85741 Garching (Germany); Kotak, R.; Inserra, C.; Fraser, M. [Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN (United Kingdom); Elias-Rosa, N. [Institut de Cincies de l'Espai (CSIC-IEEC) Campus UAB, Torre C5, Za plata, E-08193 Bellaterra, Barcelona (Spain); Haislip, J. B. [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, 120 E. Cameron Ave., Chapel Hill, NC 27599 (United States); Harutyunyan, A. [Fundacin Galileo Galilei - Telescopio Nazionale Galileo, Rambla Jos Ana Fernndez Prez 7, E-38712 Brea Baja, TF - Spain (Spain); and others

    2014-06-01

    We present an extensive optical and near-infrared photometric and spectroscopic campaign of the Type IIP supernova SN 2012aw. The data set densely covers the evolution of SN 2012aw shortly after the explosion through the end of the photospheric phase, with two additional photometric observations collected during the nebular phase, to fit the radioactive tail and estimate the {sup 56}Ni mass. Also included in our analysis is the previously published Swift UV data, therefore providing a complete view of the ultraviolet-optical-infrared evolution of the photospheric phase. On the basis of our data set, we estimate all the relevant physical parameters of SN 2012aw with our radiation-hydrodynamics code: envelope mass M {sub env} ? 20 M {sub ?}, progenitor radius R ? 3 10{sup 13} cm (?430 R {sub ?}), explosion energy E ? 1.5 foe, and initial {sup 56}Ni mass ?0.06 M {sub ?}. These mass and radius values are reasonably well supported by independent evolutionary models of the progenitor, and may suggest a progenitor mass higher than the observational limit of 16.5 1.5 M {sub ?} of the Type IIP events.

  13. A Massive Stellar Burst Before the Supernova

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A Massive Stellar Burst Before the Supernova A Massive Stellar Burst Before the Supernova February 6, 2013 Contact: Linda Vu, lvu@lbl.gov, +1 510 495 2402 An automated supernova hunt is shedding new light on the death sequence of massive stars-specifically, the kind that self-destruct in Type IIn supernova explosions. Digging through the Palomar Transient Factory (PTF) data archive housed at the Department of Energy's National Energy Research Scientific Computing Center (NERSC) at Lawrence

  14. A HIGH-RESOLUTION SPECTROSCOPIC SEARCH FOR THE REMAINING DONOR FOR TYCHO'S SUPERNOVA

    SciTech Connect (OSTI)

    Kerzendorf, Wolfgang E.; Yong, David; Schmidt, Brian P.; Murphy, Simon J.; Bessell, Michael S.; Simon, Joshua D.; Jeffery, C. Simon; Anderson, Jay; Podsiadlowski, Philipp; Gal-Yam, Avishay; Silverman, Jeffrey M.; Filippenko, Alexei V.; Nomoto, Ken'ichi; Venn, Kim A.; Foley, Ryan J.

    2013-09-10

    In this paper, we report on our analysis using Hubble Space Telescope astrometry and Keck-I HIRES spectroscopy of the central six stars of Tycho's supernova remnant (SN 1572). With these data, we measured the proper motions, radial velocities, rotational velocities, and chemical abundances of these objects. Regarding the chemical abundances, we do not confirm the unusually high [Ni/Fe] ratio previously reported for Tycho-G. Rather, we find that for all metrics in all stars, none exhibit the characteristics expected from traditional Type Ia supernova single-degenerate-scenario calculations. The only possible exception is Tycho-B, a rare, metal-poor A-type star; however, we are unable to find a suitable scenario for it. Thus, we suggest that SN 1572 cannot be explained by the standard single-degenerate model.

  15. Low-mass helium star models for type Ib supernovae - Light curves, mixing, and nucleosynthesis

    SciTech Connect (OSTI)

    Shigeyama, Toshikazu; Nomoto, Kenichi; Tsujimoto, Takuji; Hashimoto, Masaki (Tokyo Univ. (Japan) Kyushu Univ., Fukuoka (Japan))

    1990-09-01

    The applicability of theoretical models of He-star explosions to type Ib SN explosions is explored. Particular attention is given to light curves and mixing, Rayleigh-Taylor instabilities and mixing, and nucleosynthesis and the mass of Ni-56. Typical numerical results are presented in graphs, and it is concluded that the explosions of SN 1983N and SN 1983I can be accurately represented in terms of explosions of He stars with M(alpha) of 3-4 solar mass. A strong M(alpha) dependence of light-curve shape, photospheric velocity, and Ni-56 mass is found. 44 refs.

  16. Optical and ultraviolet observations of a low-velocity type II plateau supernova 2013am in M65

    SciTech Connect (OSTI)

    Zhang, Jujia; Bai, Jinming; Fan, Yufeng; Wang, Jianguo; Yi, Weimin; Wang, Chuanjun; Xin, Yuxin; Liangchang; Zhang, Xiliang; Lun, Baoli; Wang, Xueli; He, Shousheng [Yunnan Observatories (YNAO), Chinese Academy of Sciences, Kunming 650216 (China); Wang, Xiaofeng; Huang, Fang; Mo, Jun [Physics Department and Tsinghua Center for Astrophysics (THCA), Tsinghua University, Beijing 100084 (China); Mazzali, Paolo A.; Bersier, David [Astrophysics Research Institute, Liverpool John Moores University, Liverpool Science Park, 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Zhang, Tianmeng [National Astronomical Observatories of China (NAOC), Chinese Academy of Sciences, Beijing 100012 (China); Walker, Emma S., E-mail: jujia@ynao.ac.cn, E-mail: baijinming@ynao.ac.cn, E-mail: wang_xf@mail.tsinghua.edu.cn [Department of Physics, Yale University, New Haven, CT 06520-8121 (United States)

    2014-12-10

    Optical and ultraviolet observations for the nearby type II plateau supernova (SN IIP) 2013am in the nearby spiral galaxy M65 are presented in this paper. The early spectra are characterized by relatively narrow P-Cygni features, with ejecta velocities much lower than observed in normal SNe IIP (i.e., ?2000 km s{sup 1} versus ?5000 km {sup 1} in the middle of the plateau phase). Moreover, prominent Ca II absorptions are also detected in SN 2013am at relatively early phases. These spectral features are reminiscent of those seen in the low-velocity and low-luminosity SN IIP 2005cs. However, SN 2013am exhibits different photometric properties, having shorter plateau phases and brighter light curve tails if compared to SN 2005cs. Adopting R{sub V} = 3.1 and a mean value of total reddening derived from the photometric and spectroscopic methods (i.e., E(B V) = 0.55 0.19 mag), we find that SN 2013am may have reached an absolute V-band peak magnitude of 15.83 0.71 mag and produced an {sup 56}Ni mass of 0.016{sub ?0.006}{sup +0.010} M {sub ?} in the explosion. These parameters are close to those derived for SN 2008in and SN 2009N, which have been regarded as 'gap-filler' objects linking the faint SNe IIP to the normal ones. This indicates that some low-velocity SNe IIP may not necessarily result from the low-energetic explosions. The low expansion velocities could be due to a lower metallicity of the progenitor stars, a larger envelope mass ejected in the explosion, or the effect of viewing angle where these SNe were observed at an angle away from the polar direction.

  17. Stellar Evolution/Supernova Research Data Archives from the SciDAC...

    Office of Scientific and Technical Information (OSTI)

    The team has developed and used supernovae simulation codes to study Type 1Amore and core-collapse supernovae. (Taken from http:www.scidac.govphysicsgrb.html) The ...

  18. DES14X3taz: A type I superluminous supernova showing a luminous, rapidly cooling initial pre-peak bump

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Smith, M.

    2016-02-03

    Here, we present DES14X3taz, a new hydrogen-poor superluminous supernova (SLSN-I) discovered by the Dark Energy Survey (DES) supernova program, with additional photometric data provided by the Survey Using DECam for Superluminous Supernovae. Spectra obtained using Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy on the Gran Telescopio CANARIAS show DES14X3taz is an SLSN-I at z = 0.608. Multi-color photometry reveals a double-peaked light curve: a blue and relatively bright initial peak that fades rapidly prior to the slower rise of the main light curve. Our multi-color photometry allows us, for the first time, to show that the initial peak cools from 22,000more » to 8000 K over 15 rest-frame days, and is faster and brighter than any published core-collapse supernova, reaching 30% of the bolometric luminosity of the main peak. No physical (56)Ni-powered model can fit this initial peak. We show that a shock-cooling model followed by a magnetar driving the second phase of the light curve can adequately explain the entire light curve of DES14X3taz. Models involving the shock-cooling of extended circumstellar material at a distance of ≃400 R⊙ are preferred over the cooling of shock-heated surface layers of a stellar envelope. We compare DES14X3taz to the few double-peaked SLSN-I events in the literature. Although the rise times and characteristics of these initial peaks differ, there exists the tantalizing possibility that they can be explained by one physical interpretation.« less

  19. What We Know About Dark Energy From Supernovae

    ScienceCinema (OSTI)

    Filippenko, Alex [University of California, Berkeley, California, United States

    2010-01-08

    The measured distances of type Ia (white dwarf) supernovae as a function of redshift (z) have shown that the expansion of the Universe is currently accelerating, probably due to the presence of dark energy (X) having a negative pressure. Combining all of the data with existing results from large-scale structure surveys, we find a best fit for Omega M and Omega X of 0.28 and 0.72 (respectively), in excellent agreement with the values derived independently from WMAP measurements of the cosmic microwave background radiation. Thus far, the best-fit value for the dark energy equation-of-state parameter is -1, and its first derivative is consistent with zero, suggesting that the dark energy may indeed be Einstein's cosmological constant.

  20. Properties of optically selected supernova remnant candidates in M33

    SciTech Connect (OSTI)

    Lee, Jong Hwan; Lee, Myung Gyoon E-mail: mglee@astro.snu.ac.kr

    2014-10-01

    Narrowband images covering strong emission lines are efficient for surveying supernova remnants (SNRs) in nearby galaxies. Using the narrowband images provided by the Local Group Galaxy Survey, we searched for SNRs in M33. Culling the objects with enhanced [S II]/Hα and round morphology in the continuum-subtracted Hα and [S II] images, we produced a list of 199 sources. Among them, 79 are previously unknown. Their progenitor and morphology types were classified. A majority of the sample (170 objects) are likely remnants of core-collapse supernovae (SNe), and 29 are remnants of Type Ia SNe. The cumulative size distribution of these objects is found to be similar to that of the M31 remnants derived in a similar way. We obtain a power-law slope, α = 2.38 ± 0.05. Thus, a majority of the sources are considered to be in the Sedov-Taylor phase, consistent with previous findings. The histogram of the emission-line ratio ([S II]/Hα) of the remnants has two concentrations at [S II]/Hα ∼ 0.55 and ∼0.8, as in M31. Interestingly, L {sub X} (and L {sub 20cm}) of the compact center-bright objects are correlated with their optical luminosity. The remnants with X-ray emission have brighter optical surface brightnesses and smaller diameters than those without X-ray emission.

  1. Power-law cosmology, SN Ia, and BAO

    SciTech Connect (OSTI)

    Dolgov, Aleksander; Halenka, Vitali; Tkachev, Igor E-mail: vithal@umich.edu

    2014-10-01

    We revise observational constraints on the class of models of modified gravity which at low redshifts lead to a power-law cosmology. To this end we use available public data on Supernova Ia and on baryon acoustic oscillations. We show that the expansion regime a(t)?t{sup ?} with ? close to 3/2 in a spatially flat universe is a good fit to these data.

  2. TITLE AUTHORS SUBJECT SUBJECT RELATED DESCRIPTION PUBLISHER AVAILABILI...

    Office of Scientific and Technical Information (OSTI)

    Univ of Oklahoma Univ of Oklahoma ASTRONOMY AND ASTROPHYSICS Dark Energy Type Ia supernovae radiative transfer Dark Energy Type Ia supernovae radiative transfer The progress...

  3. IA Experts Listing 2014 | Department of Energy

    Energy Savers [EERE]

    IA Experts Listing 2014 IA Experts Listing 2014 PDF icon IA Experts Listing January 2014 More Documents & Publications Office of International Affairs Organization Chart PI...

  4. Steamboat IA Geothermal Facility | Open Energy Information

    Open Energy Info (EERE)

    IA Geothermal Facility Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Steamboat IA Geothermal Facility General Information Name Steamboat IA Geothermal Facility...

  5. A reconnaissance of the possible donor stars to the Kepler supernova

    SciTech Connect (OSTI)

    Kerzendorf, Wolfgang E.; Childress, Michael; Schmidt, Brian P.; Scharwächter, Julia; Do, Tuan

    2014-02-10

    The identity of Type Ia supernova progenitors remains a mystery, with various lines of evidence pointing toward either accretion from a nondegenerate companion or the rapid merger of two degenerate stars leading to the thermonuclear destruction of a white dwarf. In this paper, we spectroscopically scrutinize 24 of the brightest stars residing in the central 38'' × 38'' of the SN 1604 (Kepler) supernova remnant to search for a possible surviving companion star. We can rule out, with high certainty, a red giant companion star—a progenitor indicated by some models of the supernova remnant. Furthermore, we find no star that exhibits properties uniquely consistent with those expected of a donor star down to L > 10 L {sub ☉}. While the distribution of star properties toward the remnant are consistent with unrelated stars, we identify the most promising candidates for further astrometric and spectroscopic follow up. Such a program would either discover the donor star or place strong limits on progenitor systems to luminosities with L << L {sub ☉}.

  6. "Title","Creator/Author","Publication Date","OSTI Identifier...

    Office of Scientific and Technical Information (OSTI)

    PHYSICS; ACCURACY; COLOR; COSMOLOGICAL CONSTANT; LUMINOSITY; PHOTOMETRY; SHAPE; SUPERNOVAE Astrophysics,ASTRO",,"We combine the CfA3 supernovae Type Ia (SN Ia) sample with...

  7. TOWARD CHARACTERIZATION OF THE TYPEIIP SUPERNOVA PROGENITOR POPULATION: A STATISTICAL SAMPLE OF LIGHT CURVES FROM Pan-STARRS1

    SciTech Connect (OSTI)

    Sanders, N. E.; Soderberg, A. M.; Chornock, R.; Berger, E.; Challis, P.; Drout, M.; Kirshner, R. P.; Lunnan, R.; Marion, G. H.; Margutti, R.; McKinnon, R.; Milisavljevic, D.; Gezari, S.; Betancourt, M.; Foley, R. J.; Narayan, G.; Rest, A.; Kankare, E.; Mattila, S.; Smartt, S. J.; and others

    2015-02-01

    In recent years, wide-field sky surveys providing deep multiband imaging have presented a new path for indirectly characterizing the progenitor populations of core-collapse supernovae (SNe): systematic light-curve studies. We assemble a set of 76 grizy-band TypeIIP SN light curves from Pan-STARRS1, obtained over a constant survey program of 4yr and classified using both spectroscopy and machine-learning-based photometric techniques. We develop and apply a new Bayesian model for the full multiband evolution of each light curve in the sample. We find no evidence of a subpopulation of fast-declining explosions (historically referred to as ''TypeIIL'' SNe). However, we identify a highly significant relation between the plateau phase decay rate and peak luminosity among our SNeIIP. These results argue in favor of a single parameter, likely determined by initial stellar mass, predominantly controlling the explosions of red supergiants. This relation could also be applied for SN cosmology, offering a standardizable candle good to an intrinsic scatter of ? 0.2mag. We compare each light curve to physical models from hydrodynamic simulations to estimate progenitor initial masses and other properties of the Pan-STARRS1 TypeIIP SN sample. We show that correction of systematic discrepancies between modeled and observed SNIIP light-curve properties and an expanded grid of progenitor properties are needed to enable robust progenitor inferences from multiband light-curve samples of this kind. This work will serve as a pathfinder for photometric studies of core-collapse SNe to be conducted through future wide-field transient searches.

  8. A SUPER-SOLAR METALLICITY FOR THE PROGENITOR OF KEPLER'S SUPERNOVA

    SciTech Connect (OSTI)

    Park, Sangwook; Schenck, Andrew; Badenes, Carles; Mori, Koji; Kaida, Ryohei; Bravo, Eduardo; Eriksen, Kristoffer A.; Hughes, John P.; Slane, Patrick O.; Burrows, David N.; Lee, Jae-Joon E-mail: badenes@pitt.edu

    2013-04-10

    We have performed deep X-ray observations of the remnant of Kepler's supernova (SN 1604) as a Key Project of the Suzaku Observatory. Our main goal is to detect secondary Fe-peak elements in the supernova (SN) ejecta to gain insights into the Type Ia SN explosion mechanism and the nature of the progenitor. Here, we report our initial results. We made a conclusive detection of X-ray emission lines from highly ionized Mn, Cr, and Ni as well as Fe. The observed Mn-to-Cr line flux ratio is {approx}0.60, {approx}30% larger than that measured in Tycho's remnant. We estimate an Mn-to-Cr mass ratio of {approx}0.77, which is strongly suggestive of a large neutron excess in the progenitor star before the onset of the thermonuclear runaway. The observed Ni-to-Fe line flux ratio ({approx}0.03) corresponds to a mass ratio of {approx}0.06, which is generally consistent with the products of the explosive Si-burning regime in Type Ia explosion models, and rules out contamination from the products of neutron-rich nuclear statistical equilibrium in the shocked ejecta. Together with the previously suggested luminous nature of the explosion, these mass ratios provide strong evidence for a super-solar metallicity in the SN progenitor ({approx}3 Z{sub Sun }). Kepler's SN was likely the thermonuclear explosion of a white dwarf formed in the recent past that must have exploded through a relatively prompt channel.

  9. Long-lasting X-ray emission from type IIb supernova 2011dh and mass-loss history of the yellow supergiant progenitor

    SciTech Connect (OSTI)

    Maeda, Keiichi; Katsuda, Satoru; Bamba, Aya; Terada, Yukikatsu; Fukazawa, Yasushi

    2014-04-20

    Type IIb supernova (SN) 2011dh, with conclusive detection of an unprecedented yellow supergiant (YSG) progenitor, provides an excellent opportunity to deepen our understanding on the massive star evolution in the final centuries toward the SN explosion. In this paper, we report on detection and analyses of thermal X-ray emission from SN IIb 2011dh at ?500 days after the explosion on Chandra archival data, providing a solidly derived mass-loss rate of a YSG progenitor for the first time. We find that the circumstellar media should be dense, more than that expected from a Wolf-Rayet (W-R) star by one order of magnitude. The emission is powered by a reverse shock penetrating into an outer envelope, fully consistent with the YSG progenitor but not with a W-R progenitor. The density distribution at the outermost ejecta is much steeper than that expected from a compact W-R star, and this finding must be taken into account in modeling the early UV/optical emission from SNe IIb. The derived mass-loss rate is ?3 10{sup 6} M {sub ?} yr{sup 1} for the mass-loss velocity of ?20 km s{sup 1} in the final ?1300 yr before the explosion. The derived mass-loss properties are largely consistent with the standard wind mass-loss expected for a giant star. This is not sufficient to be a main driver to expel nearly all the hydrogen envelope. Therefore, the binary interaction, with a huge mass transfer having taken place at ? 1300 yr before the explosion, is a likely scenario to produce the YSG progenitor.

  10. NONUNIFORM EXPANSION OF THE YOUNGEST GALACTIC SUPERNOVA REMNANT G1.9+0.3

    SciTech Connect (OSTI)

    Borkowski, Kazimierz J.; Reynolds, Stephen P. [Department of Physics, North Carolina State University, Raleigh, NC 27695-8202 (United States); Green, David A. [Cavendish Laboratory, 19 J.J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Hwang, Una [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Petre, Robert [NASA/GSFC, Code 660, Greenbelt, MD 20771 (United States); Krishnamurthy, Kalyani [Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708 (United States); Willett, Rebecca, E-mail: kborkow@unity.ncsu.edu [Department of Electrical and Computing Engineering, University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2014-08-01

    We report measurements of the X-ray expansion of the youngest Galactic supernova remnant, G1.9+0.3, using Chandra observations in 2007, 2009, and 2011. The measured rates strongly deviate from uniform expansion, decreasing radially by about 60% along the X-ray bright SE-NW axis from 0.84% 0.06% yr{sup 1} to 0.52% 0.03% yr{sup 1}. This corresponds to undecelerated ages of 120-190yr, confirming the young age of G1.9+0.3 and implying a significant deceleration of the blast wave. The synchrotron-dominated X-ray emission brightens at a rate of 1.9% 0.4% yr{sup 1}. We identify bright outer and inner rims with the blast wave and reverse shock, respectively. Sharp density gradients in either the ejecta or ambient medium are required to produce the sudden deceleration of the reverse shock or the blast wave implied by the large spread in expansion ages. The blast wave could have been decelerated recently by an encounter with a modest density discontinuity in the ambient medium, such as may be found at a wind termination shock, requiring strong mass loss in the progenitor. Alternatively, the reverse shock might have encountered an order-of-magnitude density discontinuity within the ejecta, such as may be found in pulsating delayed-detonation Type Ia models. We demonstrate that the blast wave is much more decelerated than the reverse shock in these models for remnants at ages similar to G1.9+0.3. Similar effects may also be produced by dense shells possibly associated with high-velocity features in Type Ia spectra. Accounting for the asymmetry of G1.9+0.3 will require more realistic three-dimensional Type Ia models.

  11. The general relativistic instability supernova of a supermassive population III star

    SciTech Connect (OSTI)

    Chen, Ke-Jung; Woosley, Stan [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Heger, Alexander [Monash Centre for Astrophysics, Monash University, Victoria 3800 (Australia); Almgren, Ann [Center for Computational Sciences and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Whalen, Daniel J. [T-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Johnson, Jarrett L., E-mail: kchen@ucolick.org [XTD-PRI, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2014-08-01

    The formation of supermassive Population III stars with masses ?10,000 M{sub ?} in primeval galaxies in strong ultraviolet backgrounds at z ? 15 may be the most viable pathway to the formation of supermassive black holes by z ? 7. Most of these stars are expected to live for short times and then directly collapse to black holes, with little or no mass loss over their lives. However, we have now discovered that non-rotating primordial stars with masses close to 55,000 M{sub ?} can instead die as highly energetic thermonuclear supernovae powered by explosive helium burning, releasing up to 10{sup 55} erg, or about 10,000 times the energy of a Type Ia supernova. The explosion is triggered by the general relativistic contribution of thermal photons to gravity in the core of the star, which causes the core to contract and explosively burn. The energy release completely unbinds the star, leaving no compact remnant, and about half of the mass of the star is ejected into the early cosmos in the form of heavy elements. The explosion would be visible in the near infrared at z ? 20 to Euclid and the Wide-Field Infrared Survey Telescope, perhaps signaling the birth of supermassive black hole seeds and the first quasars.

  12. Solar and supernova neutrino interactions

    SciTech Connect (OSTI)

    Haxton, W.C.

    1990-11-01

    Two topics are addressed, the interactions of neutrinos during a type II supernova and the effect of current eddies on solar neutrino oscillations. The supernova discussion focuses on the nucleosynthesis that accompanies inelastic neutral current interactions of neutrinos in the mantle of a collapsing star, and on the effect of neutrino down-scattering'' and preheating on the explosion mechanism. The second half of the talk deals with the influence of solar turbulence (or density fluctuations) on the neutrino effective mass and the possibility that a time-varying neutrino flux could result. The effects of harmonic density or three-current perturbations on the oscillation probability are explored analytically and numerically. 15 refs., 5 figs.

  13. Three-dimensional simulations of pure deflagration models for thermonuclear supernovae

    SciTech Connect (OSTI)

    Long, Min; Jordan, George C. IV; Van Rossum, Daniel R.; Diemer, Benedikt; Graziani, Carlo; Kessler, Richard; Rich, Paul; Lamb, Don Q. [Flash Center for Computational Science, University of Chicago, Chicago, IL 60637 (United States); Meyer, Bradley, E-mail: long@flash.uchicago.edu [Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States)

    2014-07-10

    We present a systematic study of the pure deflagration model of Type Ia supernovae (SNe Ia) using three-dimensional, high-resolution, full-star hydrodynamical simulations, nucleosynthetic yields calculated using Lagrangian tracer particles, and light curves calculated using radiation transport. We evaluate the simulations by comparing their predicted light curves with many observed SNe Ia using the SALT2 data-driven model and find that the simulations may correspond to under-luminous SNe Iax. We explore the effects of the initial conditions on our results by varying the number of randomly selected ignition points from 63 to 3500, and the radius of the centered sphere they are confined in from 128 to 384 km. We find that the rate of nuclear burning depends on the number of ignition points at early times, the density of ignition points at intermediate times, and the radius of the confining sphere at late times. The results depend primarily on the number of ignition points, but we do not expect this to be the case in general. The simulations with few ignition points release more nuclear energy E{sub nuc}, have larger kinetic energies E{sub K}, and produce more {sup 56}Ni than those with many ignition points, and differ in the distribution of {sup 56}Ni, Si, and C/O in the ejecta. For these reasons, the simulations with few ignition points exhibit higher peak B-band absolute magnitudes M{sub B} and light curves that rise and decline more quickly; their M{sub B} and light curves resemble those of under-luminous SNe Iax, while those for simulations with many ignition points are not.

  14. Nucleosynthesis in Thermonuclear Supernovae

    SciTech Connect (OSTI)

    Claudia, Travaglio; Hix, William Raphael

    2013-01-01

    We review our understanding of the nucleosynthesis that occurs in thermonuclear supernovae and their contribution to Galactic Chemical evolution. We discuss the prospects to improve the modeling of the nucleosynthesis within simulations of these events.

  15. Supernova Remnants And GLAST

    SciTech Connect (OSTI)

    Slane, Patrick; /Harvard-Smithsonian Ctr. Astrophys.

    2011-11-29

    It has long been speculated that supernova remnants represent a major source of cosmic rays in the Galaxy. Observations over the past decade have ceremoniously unveiled direct evidence of particle acceleration in SNRs to energies approaching the knee of the cosmic ray spectrum. Nonthermal X-ray emission from shell-type SNRs reveals multi-TeV electrons, and the dynamical properties of several SNRs point to efficient acceleration of ions. Observations of TeV gamma-ray emission have confirmed the presence of energetic particles in several remnants as well, but there remains considerable debate as to whether this emission originates with high energy electrons or ions. Equally uncertain are the exact conditions that lead to efficient particle acceleration. Based on the catalog of EGRET sources, we know that there is a large population of Galactic gamma-ray sources whose distribution is similar to that of SNRs.With the increased resolution and sensitivity of GLAST, the gamma-ray SNRs from this population will be identified. Their detailed emission structure, along with their spectra, will provide the link between their environments and their spectra in other wavebands to constrain emission models and to potentially identify direct evidence of ion acceleration in SNRs. Here I summarize recent observational and theoretical work in the area of cosmic ray acceleration by SNRs, and discuss the contributions GLAST will bring to our understanding of this problem.

  16. Probing Late Neutrino Mass Properties With SupernovaNeutrinos...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Probing Late Neutrino Mass Properties With SupernovaNeutrinos Citation ... DOE Contract Number: DE-AC02-05CH11231 Resource Type: Journal Article Resource Relation: ...

  17. Supernovae of the Same Brightness, Cut From Vastly Different...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    that the progenitor system of a Type 1a supernova, called PTF 11kx, contains a red giant star. They also show that the system previously underwent at least one much...

  18. The Rise and Fall of Core-Collapse Supernovae

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    As a result, supernovae of various types are often used as "standard candles" in determining the size and expansion rate of a universe powered by dark energy. Despite decades of ...

  19. Object Classification at the Nearby Supernova Factory (Journal...

    Office of Scientific and Technical Information (OSTI)

    Nearby Supernova Factory Citation Details In-Document ... Report Number(s): LBNL-696E TRN: US200815%%72 DOE Contract Number: DE-AC02-05CH11231 Resource Type: Journal Article ...

  20. Category:Mason, IA | Open Energy Information

    Open Energy Info (EERE)

    Mason, IA Jump to: navigation, search Go Back to PV Economics By Location Media in category "Mason, IA" The following 16 files are in this category, out of 16 total....

  1. Supernova hunting with supercomputers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Supernova hunting with supercomputers Click to share on Facebook (Opens in new window) Click to share on Twitter (Opens in new window) Click to share on Reddit (Opens in new window) Click to share on Pinterest (Opens in new window) A new avenue for studying the life and death of stars opens up. This simulation of the expanding debris from a supernova explosion (shown in red) running over and shredding a nearby star (shown in blue). (Image: Daniel Kasen, Berkeley Lab/UC Berkeley) More »

  2. DES13S2cmm: The first superluminous supernova from the Dark Energy Survey

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Papadopoulos, A.; Plazas, A. A.; D"Andrea, C. B.; Sullivan, M.; Nichol, R. C.; Barbary, K.; Biswas, R.; Brown, P. J.; Covarrubias, R. A.; Finley, D. A.; et al

    2015-03-23

    We present DES13S2cmm, the first spectroscopically-confirmed superluminous supernova (SLSN) from the Dark Energy Survey (DES). We briefly discuss the data and search algorithm used to find this event in the first year of DES operations, and outline the spectroscopic data obtained from the European Southern Observatory (ESO) Very Large Telescope to confirm its redshift (z = 0.663 ± 0.001 based on the host-galaxy emission lines) and likely spectral type (type I). Using this redshift, we find MpeakU = –21.05+0.10–0.09 for the peak, rest-frame U-band absolute magnitude, and find DES13S2cmm to be located in a faint, low-metallicity (sub-solar), low stellar-mass hostmore » galaxy (log(M/M⊙) = 9.3 ± 0.3), consistent with what is seen for other SLSNe-I. We compare the bolometric light curve of DES13S2cmm to fourteen similarly well-observed SLSNe-I in the literature and find it possesses one of the slowest declining tails (beyond +30 days rest frame past peak), and is the faintest at peak. Moreover, we find the bolometric light curves of all SLSNe-I studied herein possess a dispersion of only 0.2–0.3 magnitudes between +25 and +30 days after peak (rest frame) depending on redshift range studied; this could be important for ‘standardising’ such supernovae, as is done with the more common type Ia. We fit the bolometric light curve of DES13S2cmm with two competing models for SLSNe-I – the radioactive decay of ⁵⁶Ni, and a magnetar – and find that while the magnetar is formally a better fit, neither model provides a compelling match to the data. Although we are unable to conclusively differentiate between these two physical models for this particular SLSN-I, further DES observations of more SLSNe-I should break this degeneracy, especially if the light curves of SLSNe-I can be observed beyond 100 days in the rest frame of the supernova.« less

  3. DES13S2cmm: The first superluminous supernova from the Dark Energy Survey

    SciTech Connect (OSTI)

    Papadopoulos, A.; Plazas, A. A.; D"Andrea, C. B.; Sullivan, M.; Nichol, R. C.; Barbary, K.; Biswas, R.; Brown, P. J.; Covarrubias, R. A.; Finley, D. A.; Fischer, J. A.; Foley, R. J.; Goldstein, D.; Gupta, R. R.; Kessler, R.; Kovacs, E.; Kuhlmann, S. E.; Lidman, C.; March, M.; Nugent, P. E.; Sako, M.; Smith, R. C.; Spinka, H.; Wester, W.; Abbott, T. M. C.; Abdalla, F.; Allam, S. S.; Banerji, M.; Bernstein, J. P.; Bernstein, R. A.; Carnero, A.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Eifler, T.; Evrard, A. E.; Flaugher, B.; Frieman, J. A.; Gerdes, D.; Gruen, D.; Honscheid, K.; James, D.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Maia, M. A. G.; Makler, M.; Marshall, J. L.; Merritt, K. W.; Miller, C. J.; Miquel, R.; Ogando, R.; Roe, N. A.; Romer, A. K.; Rykoff, E.; Sanchez, E.; Santiago, B. X.; Scarpine, V.; Schubnell, M.; Sevilla, I.; Soares-Santos, M.; Suchyta, E.; Swanson, M.; Tarle, G.; Thaler, J.; Tucker, L. D.; Wechsler, R. H.; Zuntz, J.

    2015-03-23

    We present DES13S2cmm, the first spectroscopically-confirmed superluminous supernova (SLSN) from the Dark Energy Survey (DES). We briefly discuss the data and search algorithm used to find this event in the first year of DES operations, and outline the spectroscopic data obtained from the European Southern Observatory (ESO) Very Large Telescope to confirm its redshift (z = 0.663 ± 0.001 based on the host-galaxy emission lines) and likely spectral type (type I). Using this redshift, we find MpeakU = –21.05+0.10–0.09 for the peak, rest-frame U-band absolute magnitude, and find DES13S2cmm to be located in a faint, low-metallicity (sub-solar), low stellar-mass host galaxy (log(M/M⊙) = 9.3 ± 0.3), consistent with what is seen for other SLSNe-I. We compare the bolometric light curve of DES13S2cmm to fourteen similarly well-observed SLSNe-I in the literature and find it possesses one of the slowest declining tails (beyond +30 days rest frame past peak), and is the faintest at peak. Moreover, we find the bolometric light curves of all SLSNe-I studied herein possess a dispersion of only 0.2–0.3 magnitudes between +25 and +30 days after peak (rest frame) depending on redshift range studied; this could be important for ‘standardising’ such supernovae, as is done with the more common type Ia. We fit the bolometric light curve of DES13S2cmm with two competing models for SLSNe-I – the radioactive decay of ⁵⁶Ni, and a magnetar – and find that while the magnetar is formally a better fit, neither model provides a compelling match to the data. Although we are unable to conclusively differentiate between these two physical models for this particular SLSN-I, further DES observations of more SLSNe-I should break this degeneracy, especially if the light curves of SLSNe-I can be observed beyond 100 days in the rest frame of the supernova.

  4. DES13S2cmm: The first superluminous supernova from the dark energy survey

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Papadopoulos, A.; D'Andrea, C. B.; Sullivan, M.; Nichol, R. C.; Barbary, K.; Biswas, R.; Brown, P. J.; Covarrubias, R. A.; Finley, D. A.; Fischer, J. A.; et al

    2015-03-23

    We present DES13S2cmm, the first spectroscopically-confirmed superluminous supernova (SLSN) from the Dark Energy Survey (DES). We briefly discuss the data and search algorithm used to find this event in the first year of DES operations, and outline the spectroscopic data obtained from the European Southern Observatory (ESO) Very Large Telescope to confirm its redshift (z = 0.663 0.001 based on the host-galaxy emission lines) and likely spectral type (type I). Using this redshift, we find MUpeak = -21.05????-0.09 for the peak, rest-frame U-band absolute magnitude, and find DES13S2cmm to be located in a faint, low metallicity (sub-solar), low stellar-massmorehost galaxy (log(M/M_sun) = 9.3 0.3); consistent with what is seen for other SLSNe-I. We compare the bolometric light curve of DES13S2cmm to fourteen similarly well-observed SLSNe-I in the literature and find it possesses one of the slowest declining tails (beyond +30 days rest frame past peak), and is the faintest at peak. Moreover, we find the bolometric light curves of all SLSNe-I studied herein possess a dispersion of only 0.2-0.3 magnitudes between +25 and +30 days after peak (rest frame) depending on redshift range studied; this could be important for 'standardising' such supernovae, as is done with the more common type Ia. We fit the bolometric light curve of DES13S2cmm with two competing models for SLSNe-I - the radioactive decay of ??Ni, and a magnetar - and find that while the magnetar is formally a better fit, neither model provides a compelling match to the data. Although we are unable to conclusively differentiate between these two physical models for this particular SLSN-I, further DES observations of more SLSNe-I should break this degeneracy, especially if the light curves of SLSNe-I can be observed beyond 100 days in the rest frame of the supernova.less

  5. DES13S2cmm: The first superluminous supernova from the Dark Energy Survey

    SciTech Connect (OSTI)

    Papadopoulos, A.; Plazas, A. A.; D"Andrea, C. B.; Sullivan, M.; Nichol, R. C.; Barbary, K.; Biswas, R.; Brown, P. J.; Covarrubias, R. A.; Finley, D. A.; Fischer, J. A.; Foley, R. J.; Goldstein, D.; Gupta, R. R.; Kessler, R.; Kovacs, E.; Kuhlmann, S. E.; Lidman, C.; March, M.; Nugent, P. E.; Sako, M.; Smith, R. C.; Spinka, H.; Wester, W.; Abbott, T. M. C.; Abdalla, F.; Allam, S. S.; Banerji, M.; Bernstein, J. P.; Bernstein, R. A.; Carnero, A.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Eifler, T.; Evrard, A. E.; Flaugher, B.; Frieman, J. A.; Gerdes, D.; Gruen, D.; Honscheid, K.; James, D.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Maia, M. A. G.; Makler, M.; Marshall, J. L.; Merritt, K. W.; Miller, C. J.; Miquel, R.; Ogando, R.; Roe, N. A.; Romer, A. K.; Rykoff, E.; Sanchez, E.; Santiago, B. X.; Scarpine, V.; Schubnell, M.; Sevilla, I.; Soares-Santos, M.; Suchyta, E.; Swanson, M.; Tarle, G.; Thaler, J.; Tucker, L. D.; Wechsler, R. H.; Zuntz, J.

    2015-03-23

    We present DES13S2cmm, the first spectroscopically-confirmed superluminous supernova (SLSN) from the Dark Energy Survey (DES). We briefly discuss the data and search algorithm used to find this event in the first year of DES operations, and outline the spectroscopic data obtained from the European Southern Observatory (ESO) Very Large Telescope to confirm its redshift (z = 0.663 0.001 based on the host-galaxy emission lines) and likely spectral type (type I). Using this redshift, we find MpeakU = 21.05+0.100.09 for the peak, rest-frame U-band absolute magnitude, and find DES13S2cmm to be located in a faint, low-metallicity (sub-solar), low stellar-mass host galaxy (log(M/M?) = 9.3 0.3), consistent with what is seen for other SLSNe-I. We compare the bolometric light curve of DES13S2cmm to fourteen similarly well-observed SLSNe-I in the literature and find it possesses one of the slowest declining tails (beyond +30 days rest frame past peak), and is the faintest at peak. Moreover, we find the bolometric light curves of all SLSNe-I studied herein possess a dispersion of only 0.20.3 magnitudes between +25 and +30 days after peak (rest frame) depending on redshift range studied; this could be important for standardising such supernovae, as is done with the more common type Ia. We fit the bolometric light curve of DES13S2cmm with two competing models for SLSNe-I the radioactive decay of ??Ni, and a magnetar and find that while the magnetar is formally a better fit, neither model provides a compelling match to the data. Although we are unable to conclusively differentiate between these two physical models for this particular SLSN-I, further DES observations of more SLSNe-I should break this degeneracy, especially if the light curves of SLSNe-I can be observed beyond 100 days in the rest frame of the supernova.

  6. Fermilab Today

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    4 percent. The key is a special type of Type Ia supernovae. Type Ia supernovae are thermonuclear explosions of white dwarfs - the very dense remnants of stars that have burned all...

  7. NONTHERMAL RADIATION FROM SUPERNOVA REMNANTS: EFFECTS OF MAGNETIC FIELD AMPLIFICATION AND PARTICLE ESCAPE

    SciTech Connect (OSTI)

    Kang, Hyesung; Jones, T. W.; Edmon, Paul P. E-mail: twj@msi.umn.edu

    2013-11-01

    We explore nonlinear effects of wave-particle interactions on the diffusive shock acceleration (DSA) process in Type Ia-like supernova remnant (SNR) blast waves by implementing phenomenological models for magnetic field amplification (MFA), Alfvnic drift, and particle escape in time-dependent numerical simulations of nonlinear DSA. For typical SNR parameters, the cosmic-ray (CR) protons can be accelerated to PeV energies only if the region of amplified field ahead of the shock is extensive enough to contain the diffusion lengths of the particles of interest. Even with the help of Alfvnic drift, it remains somewhat challenging to construct a nonlinear DSA model for SNRs in which of the order of 10% of the supernova explosion energy is converted into CR energy and the magnetic field is amplified by a factor of 10 or so in the shock precursor, while, at the same time, the energy spectrum of PeV protons is steeper than E {sup 2}. To explore the influence of these physical effects on observed SNR emission, we also compute the resulting radio-to-gamma-ray spectra. Nonthermal emission spectra, especially in X-ray and gamma-ray bands, depend on the time-dependent evolution of the CR injection process, MFA, and particle escape, as well as the shock dynamic evolution. This result comes from the fact that the high-energy end of the CR spectrum is composed of particles that are injected in the very early stages of the blast wave evolution. Thus, it is crucial to better understand the plasma wave-particle interactions associated with collisionless shocks in detailed modeling of nonthermal radiation from SNRs.

  8. A Massive Stellar Burst Before the Supernova

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A Massive Stellar Burst Before the Supernova A Massive Stellar Burst Before the Supernova February 6, 2013 Contact: Linda Vu, lvu@lbl.gov, +1 510 495 2402 An automated supernova ...

  9. Superluminous supernovae as standardizable candles and high-redshift distance probes

    SciTech Connect (OSTI)

    Inserra, C.; Smartt, S. J.

    2014-12-01

    We investigate the use of type Ic superluminous supernovae (SLSN Ic) as standardizable candles and distance indicators. Their appeal as cosmological probes stems from their remarkable peak luminosities, hot blackbody temperatures, and bright rest-frame ultraviolet emission. We present a sample of 16 published SLSN, from redshifts 0.1 to 1.2, and calculate accurate K corrections to determine uniform magnitudes in 2 synthetic rest-frame filter bandpasses with central wavelengths at 400 nm and 520 nm. At 400 nm, we find an encouragingly low scatter in their uncorrected, raw mean magnitudes with M(400) = –21.86 ± 0.35 mag for the full sample of 16 objects. We investigate the correlation between their decline rates and peak magnitude and find that the brighter events appear to decline more slowly. In a manner similar to the Phillips relation for type Ia SNe (SNe Ia), we define a ΔM {sub 20} decline relation. This correlates peak magnitude and decline over 20 days and can reduce the scatter in standardized peak magnitudes to ±0.22 mag. We further show that M(400) appears to have a strong color dependence. Redder objects are fainter and also become redder faster. Using this peak magnitudecolor evolution relation, a surprisingly low scatter of between ±0.08 mag and ±0.13 mag can be found in peak magnitudes, depending on sample selection. However, we caution that only 8 to 10 objects currently have enough data to test this peak magnitudecolor evolution relation. We conclude that SLSN Ic are promising distance indicators in the high-redshift universe in regimes beyond those possible with SNe Ia. Although the empirical relationships are encouraging, the unknown progenitor systems, how they may evolve with redshift, and the uncertain explosion physics are of some concern. The two major measurement uncertainties are the limited numbers of low-redshift, well-studied objects available to test these relationships and internal dust extinction in the host galaxies.

  10. Final Technical Report: Discovering the Nature of Dark Energy...

    Office of Scientific and Technical Information (OSTI)

    Report: Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae Saurabh W. Jha 79 ASTRONOMY AND ASTROPHYSICS dark energy; supernovae; cosmology dark...

  11. TITLE AUTHORS SUBJECT SUBJECT RELATED DESCRIPTION PUBLISHER AVAILABILI...

    Office of Scientific and Technical Information (OSTI)

    Report Discovering the Nature of Dark Energy Towards Better Distances from Type Ia Supernovae Saurabh W Jha ASTRONOMY AND ASTROPHYSICS dark energy supernovae cosmology dark...

  12. report.dvi

    Office of Scientific and Technical Information (OSTI)

    the physical nature of Type Ia supernovae, and the host galaxies in which they lie. ... Understanding the physical nature of these supernovae, and in par- ticular, determining ...

  13. IA Blog Archive | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Blog Archive IA Blog Archive RSS May 31, 2016 IA Blog Archive Global Energy Leaders Gather in California to Drive Clean Energy Development and Deployment Goal of meetings will be to expand international collaboration in clean energy research, development, demonstration and deployment to combat climate change. May 18, 2016 IA Blog Archive 10 Ways the Clean Energy Ministerial Is Speeding Up the World's Clean Energy Revolution The world needs a lot more clean energy, and fast. Here are 10 ways the

  14. Supernova Simulations from the T-6 Group at Los Alamos National Laboratory (LANL)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Woosley, Stanford

    LANL's primary effort to numerically model supernova explosions is based in the Theoretical Astrophysics Group (T-6). Both thermonuclear supernovae and core- collapse supernovae are studied, with special emphasis placed on multi-dimensional simulations. Both types of supernova require a wide range of input physics, which is provided by research efforts throughout the lab. In particular this research benefits from other LANL efforts studying massive star evolution, equations of state and aspects of neutrino physics. [From http://laastro.lanl.gov/science/computation.html

  15. Hard X-ray emission and {sup 44}Ti line features of the Tycho supernova remnant

    SciTech Connect (OSTI)

    Wang, Wei [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Li, Zhuo, E-mail: wangwei@bao.ac.cn, E-mail: zhuo.li@pku.edu.cn [Department of Astronomy and Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)

    2014-07-10

    A deep hard X-ray survey of the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) satellite has detected for the first time non-thermal emission up to 90 keV in the Tycho supernova (SN) remnant. Its 3-100 keV spectrum is fitted with a thermal bremsstrahlung of kT ? 0.81 0.45 keV plus a power-law model of ? ? 3.01 0.16. Based on diffusive shock acceleration theory, this non-thermal emission, together with radio measurements, implies that the Tycho remnant may not accelerate protons up to >PeV but to hundreds TeV. Only heavier nuclei may be accelerated to the cosmic ray spectral 'knee'. In addition, using INTEGRAL, we search for soft gamma-ray lines at 67.9 and 78.4 keV that come from the decay of radioactive {sup 44}Ti in the Tycho remnant. A bump feature in the 60-90 keV energy band, potentially associated with the {sup 44}Ti line emission, is found with a marginal significance level of ?2.6?. The corresponding 3? upper limit on the {sup 44}Ti line flux amounts to 1.5 10{sup 5} photon cm{sup 2} s{sup 1}. Implications on the progenitor of the Tycho SN, considered to be a Type Ia SN prototype, are discussed.

  16. Collective neutrino oscillations in supernovae

    SciTech Connect (OSTI)

    Duan, Huaiyu [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States)

    2014-06-24

    In a dense neutrino medium neutrinos can experience collective flavor transformation through the neutrino-neutrino forward scattering. In this talk we present some basic features of collective neutrino flavor transformation in the context in core-collapse supernovae. We also give some qualitative arguments for why and when this interesting phenomenon may occur and how it may affect supernova nucleosynthesis.

  17. Final Technical Report: Discovering the Nature of Dark Energy: Towards

    Office of Scientific and Technical Information (OSTI)

    Better Distances from Type Ia Supernovae (Technical Report) | SciTech Connect Final Technical Report: Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae Citation Details In-Document Search Title: Final Technical Report: Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae The final technical report from the project "Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae" led at

  18. DOE - Office of Legacy Management -- Titus Metals - IA 04

    Office of Legacy Management (LM)

    Titus Metals - IA 04 FUSRAP Considered Sites Site: TITUS METALS ( IA.04 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Waterloo , Iowa IA.04-1 Evaluation Year: 1987 IA.04-2 Site Operations: Extruded uranium billets to produce fuel plates for the Argonaut reactor in June, 1956. IA.04-1 IA.04-2 Site Disposition: Eliminated - Potential for contamination considered remote based on the limited scope of activities at the site and results of

  19. Cosmological and supernova neutrinos

    SciTech Connect (OSTI)

    Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Balantekin, A. B. [Department of Physics, University of Wisconsin - Madison, Wisconsin 53706 (United States); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Kusakabe, M. [School of Liberal Arts and Science, Korea Aerospace University, Goyang 412-791 (Korea, Republic of); Mathews, G. J. [Department of Physics, University of Notre Dame, IN 46556 (United States); Nakamura, K. [Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Pehlivan, Y. [Mimar Sinan GS, Department of Physics, ?i?li, ?stanbul 34380 (Turkey); Suzuki, T. [Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

    2014-06-24

    The Big Bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) anisotropies are the pillars of modern cosmology. It has recently been suggested that axion which is a dark matter candidate in the framework of the standard model could condensate in the early universe and induce photon cooling before the epoch of the photon last scattering. Although this may render a solution to the overproduction problem of primordial {sup 7}Li abundance, there arises another serious difficulty of overproducing D abundance. We propose a hybrid dark matter model with both axions and relic supersymmetric (SUSY) particles to solve both overproduction problems of the primordial D and {sup 7}Li abundances simultaneously. The BBN also serves to constrain the nature of neutrinos. Considering non-thermal photons produced in the decay of the heavy sterile neutrinos due to the magnetic moment, we explore the cosmological constraint on the strength of neutrino magnetic moment consistent with the observed light element abundances. Core-collapse supernovae eject huge flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. Combining the recent experimental constraints on ?{sub 13} with predicted and observed supernova-produced abundance ratio {sup 11}B/{sup 7}Li encapsulated in the presolar grains from the Murchison meteorite, we show a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos (SRN) that may indicate the softness of the equation of state (EoS) of nuclear matter and adiabatic conditions of the neutrino oscillation.

  20. VHE Gamma-ray Supernova Remnants

    SciTech Connect (OSTI)

    Funk, Stefan; /KIPAC, Menlo Park

    2007-01-22

    Increasing observational evidence gathered especially in X-rays and {gamma}-rays during the course of the last few years support the notion that Supernova remnants (SNRs) are Galactic particle accelerators up to energies close to the ''knee'' in the energy spectrum of Cosmic rays. This review summarizes the current status of {gamma}-ray observations of SNRs. Shell-type as well as plerionic type SNRs are addressed and prospect for observations of these two source classes with the upcoming GLAST satellite in the energy regime above 100 MeV are given.

  1. An improved multipole approximation for self-gravity and its importance for core-collapse supernova simulations

    SciTech Connect (OSTI)

    Couch, Sean M.; Graziani, Carlo; Flocke, Norbert

    2013-12-01

    Self-gravity computation by multipole expansion is a common approach in problems such as core-collapse and Type Ia supernovae, where single large condensations of mass must be treated. The standard formulation of multipole self-gravity in arbitrary coordinate systems suffers from two significant sources of error, which we correct in the formulation presented in this article. The first source of error is due to the numerical approximation that effectively places grid cell mass at the central point of the cell, then computes the gravitational potential at that point, resulting in a convergence failure of the multipole expansion. We describe a new scheme that avoids this problem by computing gravitational potential at cell faces. The second source of error is due to sub-optimal choice of location for the expansion center, which results in angular power at high multipole l values in the gravitational field, requiring a highand expensivevalue of multipole cutoff l {sub max}. By introducing a global measure of angular power in the gravitational field, we show that the optimal coordinate for the expansion is the square-density-weighted mean location. We subject our new multipole self-gravity algorithm, implemented in the FLASH simulation framework, to two rigorous test problems: MacLaurin spheroids for which exact analytic solutions are known, and core-collapse supernovae. We show that key observables of the core-collapse simulations, particularly shock expansion, proto-neutron star motion, and momentum conservation, are extremely sensitive to the accuracy of the multipole gravity, and the accuracy of their computation is greatly improved by our reformulated solver.

  2. Supernova Caught in the Act

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    explosion, a rare feat made possible by a specialized survey telescope and state-of-the-art computational tools. The discovery of such a supernova so early and so close has...

  3. IA Blog Archive | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    "always be five years away." For four key clean energy technologies, that clean energy future has already arrived. August 21, 2013 IA Blog Archive ActOnClimate: Secretary...

  4. Identification of a jet-driven supernova remnant in the Small Magellanic Cloud: Possible evidence for the enhancement of bipolar explosions at low metallicity

    SciTech Connect (OSTI)

    Lopez, Laura A.; Castro, Daniel; Slane, Patrick O.; Ramirez-Ruiz, Enrico; Badenes, Carles

    2014-06-10

    Recent evidence has suggested that the supernova remnant (SNR) 010472.3 in the Small Magellanic Cloud (SMC) may be the result of a 'prompt' Type Ia SN on the basis of enhanced iron abundances and its association with a star-forming region. In this paper, we present evidence that SNR 010472.3 arose from a jet-driven bipolar core-collapse (CC) SN. Specifically, we use serendipitous Chandra data of SNR 010472.3 taken because of its proximity to the calibration source SNR E010272.3. We analyze 56 Advanced CCD Imaging Spectrometer (ACIS) observations of SNR 010472.3 to produce imaging and spectra with an effective exposure of 528.6 ks. We demonstrate that SNR 010472.3 is highly elliptical relative to other nearby young SNRs, suggesting a CC SN origin. Furthermore, we compare ejecta abundances derived from spectral fits to nucleosynthetic yields of Type Ia and CC SNe, and we find that the iron, neon, and silicon abundances are consistent with either a spherical CC SN of a 18-20 M {sub ?} progenitor or an aspherical CC SN of a 25 M {sub ?} progenitor. We show that the star formation history at the site of SNR 010472.3 is also consistent with a CC origin. Given the bipolar morphology of the SNR, we favor the aspherical CC SN scenario. This result may suggest jet-driven SNe occur frequently in the low-metallicity environment of the SMC, consistent with the observational and theoretical work on broad-line Type Ic SNe and long-duration gamma-ray bursts.

  5. The supernova that destroyed a galaxy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The supernova that destroyed a galaxy The supernova that destroyed a galaxy The research may solve the long-standing puzzle of how supermassive black holes were formed in the...

  6. How Do Standard Candles Illuminate Knowledge of the Universe...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Type Ia supernovae (SNe Ia) are among the brightest exploding stars in the universe. Observations using SNe Ia as "standard candles" led to the discovery of dark energy. Most ...

  7. Electron-capture supernovae of super-asymptotic giant branch stars and the Crab supernova 1054

    SciTech Connect (OSTI)

    Nomoto, Ken'ichi [Kavli Institute for Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Tominaga, Nozomu [Department of Physics, Faculty of Science and Engineering, Konan University, 8-9-1 Okamoto, Kobe, Hyogo 658-8501, Japan and Kavli Institute for Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Blinnikov, Sergei I. [Institute for Theoretical and Experimental Physics (ITEP), Moscow 117218, Russia and Kavli Institute for Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan)

    2014-05-02

    An electron-capture supernova (ECSN) is a core-collapse supernova explosion of a super-asymptotic giant branch (SAGB) star with a main-sequence mass M{sub Ms} ? 7 - 9.5M{sub ?}. The explosion takes place in accordance with core bounce and subsequent neutrino heating and is a unique example successfully produced by first-principle simulations. This allows us to derive a first self-consistent multicolor light curves of a core-collapse supernova. Adopting the explosion properties derived by the first-principle simulation, i.e., the low explosion energy of 1.5 10{sup 50} erg and the small {sup 56}Ni mass of 2.5 10{sup ?3} M{sub ?}, we perform a multigroup radiation hydrodynamics calculation of ECSNe and present multicolor light curves of ECSNe of SAGB stars with various envelope mass and hydrogen abundance. We demonstrate that a shock breakout has peak luminosity of L ? 2 10{sup 44} erg s{sup ?1} and can evaporate circumstellar dust up to R ? 10{sup 17} cm for a case of carbon dust, that plateau luminosity and plateau duration of ECSNe are L ? 10{sup 42} erg s{sup ?1} and {sup t} ? 60 - 100 days, respectively, and that a plateau is followed by a tail with a luminosity drop by ? 4 mag. The ECSN shows a bright and short plateau that is as bright as typical Type II plateau supernovae, and a faint tail that might be influenced by spin-down luminosity of a newborn pulsar. Furthermore, the theoretical models are compared with ECSN candidates: SN 1054 and SN 2008S. We find that SN 1054 shares the characteristics of the ECSNe. For SN 2008S, we find that its faint plateau requires a ECSN model with a significantly low explosion energy of E ? 10{sup 48} erg.

  8. A survey of infrared supernova remnants in the Large Magellanic Cloud

    SciTech Connect (OSTI)

    Seok, Ji Yeon; Koo, Bon-Chul; Onaka, Takashi

    2013-12-20

    We present a comprehensive infrared study of supernova remnants (SNRs) in the Large Magellanic Cloud (LMC) using near- to mid-infrared images taken by Infrared Array Camera (IRAC; 3.6, 4.5, 5.8, and 8 μm) and Multiband Imaging Photometer (MIPS; 24 and 70 μm) onboard the Spitzer Space Telescope. Among the 47 bona fide LMC SNRs, 29 were detected in infrared, giving a high detection rate of 62%. All 29 SNRs show emission at 24 μm, and 20 out of 29 show emission in one or several IRAC bands. We present their 4.5, 8, 24, and 70 μm images and a table summarizing their Spitzer fluxes. We find that the LMC SNRs are considerably fainter than the Galactic SNRs, and that, among the LMC SNRs, Type Ia SNRs are significantly fainter than core-collapse SNRs. We conclude that the MIPS emission of essentially all SNRs originates from dust emission, whereas their IRAC emissions originate from ionic/molecular lines, polycyclic aromatic hydrocarbons emission, or synchrotron emission. The infrared fluxes show correlation with radio and X-ray fluxes. For SNRs that have similar morphology in infrared and X-rays, the ratios of 24 to 70 μm fluxes have good correlation with the electron density of hot plasma. The overall correlation is explained well by the emission from collisionally heated silicate grains of 0.1 μm size, but for mature SNRs with relatively low gas temperatures, the smaller-sized grain population is favored more. For those that appear different between infrared and X-rays, the emission in the MIPS bands is probably from dust heated by shock radiation.

  9. Supernova neutrinos and explosive nucleosynthesis

    SciTech Connect (OSTI)

    Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J.; Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Mathews, G. J. [Center for Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Nakamura, K. [Faculty of Science and Engineering, Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Suzuki, T. [Department of Physics, College of Humanities and Sciences, Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

    2014-05-09

    Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta as well as r-process nuclei are affected by the neutrino interactions. The abundance of these isotopes therefore depends strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We discuss first how to determine the neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the effects of neutrino oscillation on their abundances, and propose a novel method to determine the still unknown neutrino oscillation parameters, mass hierarchy and ?{sub 13}, simultaneously. There is recent evidence that SiC X grains from the Murchison meteorite may contain supernova-produced light elements {sup 11}B and {sup 7}Li encapsulated in the presolar grains. Combining the recent experimental constraints on ?{sub 13}, we show that our method sug-gests at a marginal preference for an inverted neutrino mass hierarchy. Finally, we discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

  10. A threat-based definition of IA- and IA-enabled products.

    SciTech Connect (OSTI)

    Shakamuri, Mayuri; Schaefer, Mark A.; Campbell, Philip LaRoche

    2010-07-01

    This paper proposes a definition of 'IA and IA-enabled products' based on threat, as opposed to 'security services' (i.e., 'confidentiality, authentication, integrity, access control or non-repudiation of data'), as provided by Department of Defense (DoD) Instruction 8500.2, 'Information Assurance (IA) Implementation.' The DoDI 8500.2 definition is too broad, making it difficult to distinguish products that need higher protection from those that do not. As a consequence the products that need higher protection do not receive it, increasing risk. The threat-based definition proposed in this paper solves those problems by focusing attention on threats, thereby moving beyond compliance to risk management. (DoDI 8500.2 provides the definitions and controls that form the basis for IA across the DoD.) Familiarity with 8500.2 is assumed.

  11. A threat-based definition of IA and IA-enabled products.

    SciTech Connect (OSTI)

    Shakamuri, Mayuri; Schaefer, Mark A.; Campbell, Philip LaRoche

    2010-09-01

    This paper proposes a definition of 'IA and IA-enabled products' based on threat, as opposed to 'security services' (i.e., 'confidentiality, authentication, integrity, access control or non-repudiation of data'), as provided by Department of Defense (DoD) Instruction 8500.2, 'Information Assurance (IA) Implementation.' The DoDI 8500.2 definition is too broad, making it difficult to distinguish products that need higher protection from those that do not. As a consequence the products that need higher protection do not receive it, increasing risk. The threat-based definition proposed in this paper solves those problems by focusing attention on threats, thereby moving beyond compliance to risk management. (DoDI 8500.2 provides the definitions and controls that form the basis for IA across the DoD.) Familiarity with 8500.2 is assumed.

  12. A fast contour descriptor algorithm for supernova imageclassification

    SciTech Connect (OSTI)

    Aragon, Cecilia R.; Aragon, David Bradburn

    2006-07-16

    We describe a fast contour descriptor algorithm and its application to a distributed supernova detection system (the Nearby Supernova Factory) that processes 600,000 candidate objects in 80 GB of image data per night. Our shape-detection algorithm reduced the number of false positives generated by the supernova search pipeline by 41% while producing no measurable impact on running time. Fourier descriptors are an established method of numerically describing the shapes of object contours, but transform-based techniques are ordinarily avoided in this type of application due to their computational cost. We devised a fast contour descriptor implementation for supernova candidates that meets the tight processing budget of the application. Using the lowest-order descriptors (F{sub 1} and F{sub -1}) and the total variance in the contour, we obtain one feature representing the eccentricity of the object and another denoting its irregularity. Because the number of Fourier terms to be calculated is fixed and small, the algorithm runs in linear time, rather than the O(n log n) time of an FFT. Constraints on object size allow further optimizations so that the total cost of producing the required contour descriptors is about 4n addition/subtraction operations, where n is the length of the contour.

  13. The Tip of the red giant branch distance to the perfect spiral galaxy M74 hosting three core-collapse supernovae

    SciTech Connect (OSTI)

    Sung Jang, In; Gyoon Lee, Myung E-mail: mglee@astro.snu.ac.kr

    2014-09-01

    M74 (NGC 628) is a famous face-on spiral galaxy, hosting three core-collapse supernovae (SNe): SN Ic 2002ap, SN II-P 2003gd, and SN II-P 2013ej. However, its distance is not well known. We present a distance estimation for this galaxy based on the Tip of the Red Giant Branch (TRGB) method. We obtain photometry of the resolved stars in the arm-free region of M74 from F555W and F814W images in the Hubble Space Telescope archive. The color-magnitude diagram of the resolved stars shows a dominant red giant branch (RGB) as well as blue main sequence stars, red helium burning stars, and asymptotic giant branch stars. The I-band luminosity function of the RGB stars shows the TRGB to be at I {sub TRGB} = 26.13 ± 0.03 mag, and T {sub RGB} = 25.97 ± 0.03. From this, we derive the distance modulus to M74 to be 30.04 ± 0.04 (random) ± 0.12 (systematic) (corresponding to a linear distance of 10.19 ± 0.14 ± 0.56 Mpc). With this distance estimate, we calibrate the standardized candle method for SNe II-P. From the absolute magnitudes of SN 2003gd, we derive a value of the Hubble constant, H {sub 0} = 72 ± 6 (random) ± 7 (systematic) km s{sup –1} Mpc{sup –1}. It is similar to recent estimates based on the luminosity calibration of Type Ia supernovae.

  14. IA News Archive | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    News Archive IA News Archive RSS July 22, 2016 Energy Department Selects Argonne National Laboratory to Lead U.S. Consortium for New CERC Medium- and Heavy-Duty Truck Technical Track The New Consortium of University, Private Sector and National Laboratory Partners will Advance Collaboration between the U.S. and China on Truck Efficiency Technologies June 10, 2016 Energy Department Invests More than $10 Million in Efficient Lighting Research and Development New projects designed to save consumers

  15. The supernova that destroyed a galaxy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The supernova that destroyed a galaxy The supernova that destroyed a galaxy The research may solve the long-standing puzzle of how supermassive black holes were formed in the centers of some galaxies less then a billion years after the Big Bang. August 5, 2013 Supernova of a 55,000 solar-mass star in a primitive galaxy (explosion in a low-density region) Supernova of a 55,000 solar-mass star in a primitive galaxy (explosion in a low-density region) The Los Alamos simulation is the most realistic

  16. Thermonuclear supernovae: probing magnetic fields by positrons and late-time IR line profiles

    SciTech Connect (OSTI)

    Penney, R.; Hoeflich, P. E-mail: rpenney@g.clemson.edu

    2014-11-01

    We show the importance of γ and positron transport for the formation of late-time spectra in Type Ia supernovae (SNe Ia). The goal is to study the imprint of magnetic fields (B) on late-time IR line profiles, particularly the [Fe II] feature at 1.644 μm, which becomes prominent two to three months after the explosion. As a benchmark, we use the explosion of a Chandrasekhar mass (M {sub Ch}) white dwarf (WD) and, specifically, a delayed detonation model that can reproduce the light curves and spectra for a Branch-normal SN Ia. We assume WDs with initial magnetic surface fields between 1 and 10{sup 9} G. We discuss large-scale dipole and small-scale magnetic fields. We show that positron transport effects must be taken into account for the interpretation of emission features starting at about one to two years after maximum light, depending on the size of B. The [Fe II] line profile and its evolution with time can be understood in terms of the overall energy input by radioactive decay and the transition from a γ-ray to a positron-dominated regime. We find that the [Fe II] line at 1.644 μm can be used to analyze the overall chemical and density structure of the exploding WD up to day 200 without considering B. At later times, positron transport and magnetic field effects become important. After about day 300, the line profile allows one to probe the size of the B-field. The profile becomes sensitive to the morphology of B at about day 500. In the presence of a large-scale dipole field, a broad line is produced in M {sub Ch} mass explosions that may appear flat-topped or rounded depending on the inclination at which the SN is observed. Small or no directional dependence of the spectra is found for small-scale B. We note that narrow-line profiles require central {sup 56}Ni as shown in our previous studies. Persistent broad-line, flat-topped profiles require high-density burning, which is the signature of a WD close to M {sub Ch}. Good time coverage is required to

  17. Multigroup Radiation Transport in Supernova Light Curve Calculations...

    Office of Scientific and Technical Information (OSTI)

    Multigroup Radiation Transport in Supernova Light Curve Calculations Citation Details In-Document Search Title: Multigroup Radiation Transport in Supernova Light Curve Calculations ...

  18. Core-Collapse Supernovae and Host Galaxy Stellar Populations...

    Office of Scientific and Technical Information (OSTI)

    Core-Collapse Supernovae and Host Galaxy Stellar Populations Citation Details In-Document Search Title: Core-Collapse Supernovae and Host Galaxy Stellar Populations Authors: Kelly, ...

  19. Multigroup Radiation Transport in Supernova Light Curve Calculations...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Multigroup Radiation Transport in Supernova Light Curve Calculations Citation Details In-Document Search Title: Multigroup Radiation Transport in Supernova Light ...

  20. The ESSENCE Supernova Survey: Survey Optimization, Observations...

    Office of Scientific and Technical Information (OSTI)

    Ia SNe, at redshifts from 0.10 to 0.78, identified through an impartial, effective methodology for spectroscopic classification and redshift determination. We present the...

  1. Classifying supernovae using only galaxy data

    SciTech Connect (OSTI)

    Foley, Ryan J.; Mandel, Kaisey

    2013-12-01

    We present a new method for probabilistically classifying supernovae (SNe) without using SN spectral or photometric data. Unlike all previous studies to classify SNe without spectra, this technique does not use any SN photometry. Instead, the method relies on host-galaxy data. We build upon the well-known correlations between SN classes and host-galaxy properties, specifically that core-collapse SNe rarely occur in red, luminous, or early-type galaxies. Using the nearly spectroscopically complete Lick Observatory Supernova Search sample of SNe, we determine SN fractions as a function of host-galaxy properties. Using these data as inputs, we construct a Bayesian method for determining the probability that an SN is of a particular class. This method improves a common classification figure of merit by a factor of >2, comparable to the best light-curve classification techniques. Of the galaxy properties examined, morphology provides the most discriminating information. We further validate this method using SN samples from the Sloan Digital Sky Survey and the Palomar Transient Factory. We demonstrate that this method has wide-ranging applications, including separating different subclasses of SNe and determining the probability that an SN is of a particular class before photometry or even spectra can. Since this method uses completely independent data from light-curve techniques, there is potential to further improve the overall purity and completeness of SN samples and to test systematic biases of the light-curve techniques. Further enhancements to the host-galaxy method, including additional host-galaxy properties, combination with light-curve methods, and hybrid methods, should further improve the quality of SN samples from past, current, and future transient surveys.

  2. Machine learning helps discover the most luminous supernova in history

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Machine learning helps discover supernova Machine learning helps discover the most luminous supernova in history Machine-learning technology developed at Los Alamos National Laboratory played a key role in the discovery of supernova ASASSN-15lh. January 14, 2016 An artist's impression of the record-breaking superluminous supernova ASASSN-15lh as it would appear from an exoplanet located about 10,000 light years away in the host galaxy of the supernova. (Credit: Beijing Planetarium / Jin Ma) An

  3. Supernova Twins: Making Standard Candles More Standard Than Ever

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Supernova Twins: Making Standard Candles More Standard Than Ever Supernova Twins: Making Standard Candles More Standard Than Ever New Modeling Method Measures Cosmological Distances With Far Greater Accuracy January 13, 2016 Contact: Paul Preuss, paul_preuss@lbl.gov, +1 415 272 3253 supernovatwins From left, Greg Aldering, Kyle Boone, Hannah Fakhouri and Saul Perlmutter of the Nearby Supernova Factory. Behind them is a poster of a supernova spectrum. Matching spectra among different supernovae

  4. Supernova relic neutrinos and the supernova rate problem: Analysis of uncertainties and detectability of ONeMg and failed supernovae

    SciTech Connect (OSTI)

    Mathews, Grant J. [Center for Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Hidaka, Jun; Kajino, Toshitaka; Suzuki, Jyutaro [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2014-08-01

    Direct measurements of the core collapse supernova rate (R{sub SN}) in the redshift range 0 ? z ? 1 appear to be about a factor of two smaller than the rate inferred from the measured cosmic massive star formation rate (SFR). This discrepancy would imply that about one-half of the massive stars that have been born in the local observed comoving volume did not explode as luminous supernovae. In this work, we explore the possibility that one could clarify the source of this 'supernova rate problem' by detecting the energy spectrum of supernova relic neutrinos with a next generation 10{sup 6} ton water ?erenkov detector like Hyper-Kamiokande. First, we re-examine the supernova rate problem. We make a conservative alternative compilation of the measured SFR data over the redshift range 0 ?z ? 7. We show that by only including published SFR data for which the dust obscuration has been directly determined, the ratio of the observed massive SFR to the observed supernova rate R{sub SN} has large uncertainties ?1.8{sub ?0.6}{sup +1.6} and is statistically consistent with no supernova rate problem. If we further consider that a significant fraction of massive stars will end their lives as faint ONeMg SNe or as failed SNe leading to a black hole remnant, then the ratio reduces to ?1.1{sub ?0.4}{sup +1.0} and the rate problem is essentially solved. We next examine the prospects for detecting this solution to the supernova rate problem. We first study the sources of uncertainty involved in the theoretical estimates of the neutrino detection rate and analyze whether the spectrum of relic neutrinos can be used to independently identify the existence of a supernova rate problem and its source. We consider an ensemble of published and unpublished core collapse supernova simulation models to estimate the uncertainties in the anticipated neutrino luminosities and temperatures. We illustrate how the spectrum of detector events might be used to establish the average neutrino

  5. ON THE PROGENITOR AND SUPERNOVA OF THE SN 2002cx-LIKE SUPERNOVA...

    Office of Scientific and Technical Information (OSTI)

    Republica 252, Santiago (Chile) Departamento de AstronomIa, Universidad de Chile, Santiago (Chile) Carnegie Observatories, Las Campanas Observatory, Casilla 601, La Serena (Chile) ...

  6. DOE - Office of Legacy Management -- Bendix Aviation Corp Pioneer Div - IA

    Office of Legacy Management (LM)

    05 Corp Pioneer Div - IA 05 FUSRAP Considered Sites Site: BENDIX AVIATION CORP., PIONEER DIV. (IA.05 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: Pioneer Division, Bendix Aviation Corporation Bendix Aviation Corporation Bendix Pioneer Division IA.05-1 IA.05-2 IA.05-3 Location: Davenport , Iowa IA.05-1 Evaluation Year: 1990 IA.05-2 IA.05-4 Site Operations: Conducted studies to investigate the feasibility of using sonic cleaning equipment to

  7. ANTIPROTONS PRODUCED IN SUPERNOVA REMNANTS

    SciTech Connect (OSTI)

    Berezhko, E. G.; Ksenofontov, L. T.

    2014-08-20

    We present the energy spectrum of an antiproton cosmic ray (CR) component calculated on the basis of the nonlinear kinetic model of CR production in supernova remnants (SNRs). The model includes the reacceleration of antiprotons already existing in the interstellar medium as well as the creation of antiprotons in nuclear collisions of accelerated protons with gas nuclei and their subsequent acceleration by SNR shocks. It is shown that the production of antiprotons in SNRs produces a considerable effect in their resultant energy spectrum, making it essentially flatter above 10 GeV so that the spectrum at TeV energies increases by a factor of 5. The calculated antiproton spectrum is consistent with the PAMELA data, which correspond to energies below 100 GeV. As a consistency check, we have also calculated within the same model the energy spectra of secondary nuclei and show that the measured boron-to-carbon ratio is consistent with the significant SNR contribution.

  8. Supercomputing and the search for supernovae

    ScienceCinema (OSTI)

    Nugent, Peter

    2014-06-23

    Berkeley Lab's Peter Nugent discusses "Supercomputing and the search for supernovae" in this Oct. 28, 2013 talk, which is part of a Science at the Theater event entitled Eight Big Ideas.

  9. Supernova cooling in a dark matter smog

    SciTech Connect (OSTI)

    Zhang, Yue

    2014-11-27

    A light hidden gauge boson with kinetic mixing with the usual photon is a popular setup in theories of dark matter. The supernova cooling via radiating the hidden boson is known to put an important constraint on the mixing. I consider the possible role dark matter, which under reasonable assumptions naturally exists inside supernova, can play in the cooling picture. Because the interaction between the hidden gauge boson and DM is likely unsuppressed, even a small number of dark matter compared to protons inside the supernova could dramatically shorten the free streaming length of the hidden boson. A picture of a dark matter “smog” inside the supernova, which substantially relaxes the cooling constraint, is discussed in detail.

  10. How to See a Recently Discovered Supernova

    ScienceCinema (OSTI)

    Nugent, Peter

    2013-05-29

    Berkeley Lab scientist Peter Nugent discusses a recently discovered supernova that is closer to Earth ? approximately 21 million light-years away ? than any other of its kind in a generation. Astronomers believe they caught the supernova within hours of its explosion, a rare feat made possible with a specialized survey telescope and state-of-the-art computational tools. The finding of such a supernova so early and so close has energized the astronomical community as they are scrambling to observe it with as many telescopes as possible, including the Hubble Space Telescope. More info on how to see it: http://newscenter.lbl.gov/feature-stories/2011/08/31/glimpse-cosmic-explosion/ News release: http://newscenter.lbl.gov/feature-stories/2011/08/25/supernova/

  11. Final Technical Report: Discovering the Nature of Dark Energy...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Final Technical Report: Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae Citation Details In-Document Search Title: Final...

  12. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    for a way to improve these results? Final Technical Report: Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae Saurabh W. Jha The...

  13. Discovering the Nature of Dark Energy: Towards Better Distances...

    Office of Scientific and Technical Information (OSTI)

    the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae -- Final Technical Report Citation Details In-Document Search Title: Discovering the Nature of Dark ...

  14. "Title","Creator/Author","Publication Date","OSTI Identifier...

    Office of Scientific and Technical Information (OSTI)

    Energy Physics (HEP) (SC-25)","79 ASTRONOMY AND ASTROPHYSICS Dark Energy, Type Ia supernovae, radiative transfer,",,"The progress over the course of the grant period was...

  15. Final Technical Report: Discovering the Nature of Dark Energy...

    Office of Scientific and Technical Information (OSTI)

    the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae Citation Details In-Document Search Title: Final Technical Report: Discovering the Nature of Dark ...

  16. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Everything1 Electronic Full Text1 Citations0 Multimedia0 Datasets0 Software0 Filter Results Filter by Subject astronomy and astrophysics dark energy, type ia supernovae, radiative ...

  17. Discovering the Nature of Dark Energy: Towards Better Distances...

    Office of Scientific and Technical Information (OSTI)

    Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae -- Final Technical Report Filippenko, Alexei Vladimir Univ. California, Berkeley 79...

  18. "Title","Creator/Author","Publication Date","OSTI Identifier...

    Office of Scientific and Technical Information (OSTI)

    Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae -- Final Technical Report","Filippenko, Alexei Vladimir Univ. California,...

  19. TITLE AUTHORS SUBJECT SUBJECT RELATED DESCRIPTION PUBLISHER AVAILABILI...

    Office of Scientific and Technical Information (OSTI)

    Discovering the Nature of Dark Energy Towards Better Distances from Type Ia Supernovae Final Technical Report Filippenko Alexei Vladimir Univ California Berkeley ASTRONOMY AND...

  20. DOE - Office of Legacy Management -- Iowa Army Ammunition Plant - IA 02

    Office of Legacy Management (LM)

    Army Ammunition Plant - IA 02 FUSRAP Considered Sites Iowa Army Ammunition Plant, IA Alternate Name(s): Burlington Ordnance Plant Iowa Ordnance Plant Silas Mason Company IA.02-3 Location: Located in Township 70 North, Range 3 West, Section 32, 5th Principal Meridian, Des Moines County, Burlington, Iowa IA.02-1 IA.02-5 Historical Operations: Assembled nuclear weapons, primarily high explosive components and conducted explosives testing using the high explosive components and depleted uranium. AEC

  1. Tidally-Induced Thermonuclear Supernovae

    SciTech Connect (OSTI)

    Rosswog, S.; Ramirez-Ruiz, E.; Hix, William Raphael

    2009-01-01

    We discuss the results of 3D simulations of tidal disruptions of white dwarfs by moderate-mass black holes as they may exist in the cores of globular clusters or dwarf galaxies. Our simulations follow self-consistently the hydrodynamic and nuclear evolution from the initial parabolic orbit over the disruption to the build-up of an accretion disk around the black hole. For strong enough encounters (pericentre distances smaller than about 1/3 of the tidal radius) the tidal compression is reversed by a shock and finally results in a thermonuclear explosion. These explosions are not restricted to progenitor masses close to the Chandrasekhar limit, we find exploding examples throughout the whole white dwarf mass range. There is, however, a restriction on the masses of the involved black holes: black holes more massive than 2x105M{circle_dot} swallow a typical 0.6M{circle_dot} white dwarf before their tidal forces can overwhelm the star's selfgravity. Therefore, this mechanism is characteristic for black holes of moderate masses. The material that remains bound to the black hole settles into an accretion disk and produces an Xray flare close to the Eddington limit of L{sub Edd} {approx} 10{sup 41}erg/s (Mbh/1000M{circle_dot}), typically lasting for a few months. The combination of a peculiar thermonuclear supernova together with an X-ray flare thus whistle-blows the existence of such moderate-mass black holes. The next generation of wide field space-based instruments should be able to detect such events.

  2. Nuclear Physics in Core-Collapse Supernovae

    SciTech Connect (OSTI)

    Liebendoerfer, Matthias; Fischer, T.; Froelich, C.; Hix, William Raphael; Langanke, Karlheinz; Martinez-Pinedo, Gabriel; Mezzacappa, Anthony; Scheidegger, Simon; Thielemann, Friedrich-Karl W.; Whitehouse, Stuart

    2008-01-01

    Core-collapse and the launch of a supernova explosion form a very short episode of few seconds in the evolution of a massive star, during which an enormous gravitational energy of several times 1053 erg is transformed into observable neutrino-, kinetic-, and electromagnetic radiation energy. We emphasize the wide range of matter conditions that prevail in a supernova event and sort the conditions into distinct regimes in the density and entropy phase diagram to briefly discuss their different impact on the neutrino signal, gravitational wave emission, and ejecta.

  3. Nuclear Physics in Core-Collapse Supernovae

    SciTech Connect (OSTI)

    Liebendoerfer, M.; Fischer, T.; Froelich, C.; Hix, William Raphael; Langanke, Karlheinz; Mart�nez-Pinedo, Gabriel; Mezzacappa, Anthony; Scheidegger, Simon; Thielemann, F.-K.; Whitehouse, S.

    2008-10-01

    Core collapse and the launch of a supernova explosion form a very short episode of a few seconds in the evolution of a massive star, during which an enormous gravitational energy of several times 10^{51} erg is transformed into observable neutrino, kinetic, and optical energy. We emphasize the wide range of matter conditions that prevail in a supernova event and sort the conditions into distinct regimes in the density and entropy phase diagram to briefly discuss their different impact on the neutrino signal, gravitational wave emission, and ejecta.

  4. Core-collapse supernova neutrinos and neutrino properties

    SciTech Connect (OSTI)

    Gava, J.; Volpe, C.

    2008-08-29

    Core-collapse supernovae are powerful neutrino sources. The observation of a future (extra-)galactic supernova explosion or of the relic supernova neutrinos might provide important information on the supernova dynamics, on the supernova formation rate and on neutrino properties. One might learn more about unknown neutrino properties either from indirect effects in the supernova (e.g. on the explosion or on in the r-process) or from modifications of the neutrino time or energy distributions in a detector on Earth. Here we will discuss in particular possible effects of CP violation in the lepton sector. We will also mention the interest of future neutrino-nucleus interaction measurements for the precise knowledge of supernova neutrino detector response to electron neutrinos.

  5. Multipole expansion method for supernova neutrino oscillations

    SciTech Connect (OSTI)

    Duan, Huaiyu; Shalgar, Shashank, E-mail: duan@unm.edu, E-mail: shashankshalgar@unm.edu [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States)

    2014-10-01

    We demonstrate a multipole expansion method to calculate collective neutrino oscillations in supernovae using the neutrino bulb model. We show that it is much more efficient to solve multi-angle neutrino oscillations in multipole basis than in angle basis. The multipole expansion method also provides interesting insights into multi-angle calculations that were accomplished previously in angle basis.

  6. Essential Ingredients in Core-collapse Supernovae

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hix, William Raphael; Lentz, E. J.; Endeve, Eirik; Baird, Mark L.; Chertkow, Merek A.; Harris, James A.; Messer, Bronson; Mezzacappa, Anthony; Bruenn, S. W.; Blondin, J. M.

    2014-03-27

    Marking the inevitable death of a massive star, and the birth of a neutron star or black hole, core-collapse supernovae bring together physics at a wide range in spatial scales, from kilometer-sized hydrodynamic motions (eventually growing to gigameter scale) down to femtometer scale nuclear reactions. Carrying 10more » $$^{44}$$ joules of kinetic energy and a rich-mix of newly synthesized atomic nuclei, core-collapse supernovae are the preeminent foundries of the nuclear species which make up ourselves and our solar system. We will discuss our emerging understanding of the convectively unstable, neutrino-driven explosion mechanism, based on increasingly realistic neutrino-radiation hydrodynamic simulations that include progressively better nuclear and particle physics. Recent multi-dimensional models with spectral neutrino transport from several research groups, which slowly develop successful explosions for a range of progenitors, have motivated changes in our understanding of the neutrino reheating mechanism. In a similar fashion, improvements in nuclear physics, most notably explorations of weak interactions on nuclei and the nuclear equation of state, continue to refine our understanding of how supernovae explode. Recent progress on both the macroscopic and microscopic effects that affect core-collapse supernovae are discussed.« less

  7. Weak-interaction processes in core-collapse supernovae

    SciTech Connect (OSTI)

    Langanke, K.

    2015-02-24

    Weak interaction processes play an important role for the dynamics of a core-collapse supernova. Due to progress of nuclear modeling and constrained by data it has been possible to improve the rates of these processes for supernova conditions decisively. This manuscript describes the recent advances and the current status in deriving electron capture rates on nuclei and of inelastic neutrino-nucleus scattering for applications in supernova simulations and briefly discusses their impact on such studies.

  8. Computational Astrophysics Consortium 3 - Supernovae, Gamma-Ray Bursts and

    Office of Scientific and Technical Information (OSTI)

    Nucleosynthesis (Technical Report) | SciTech Connect Computational Astrophysics Consortium 3 - Supernovae, Gamma-Ray Bursts and Nucleosynthesis Citation Details In-Document Search Title: Computational Astrophysics Consortium 3 - Supernovae, Gamma-Ray Bursts and Nucleosynthesis Final project report for UCSC's participation in the Computational Astrophysics Consortium - Supernovae, Gamma-Ray Bursts and Nucleosynthesis. As an appendix, the report of the entire Consortium is also appended.

  9. Supernovae and gamma-ray bursts connection

    SciTech Connect (OSTI)

    Valle, Massimo Della

    2015-12-17

    I’ll review the status of the Supernova/Gamma-Ray Burst connection. Several pieces of evidence suggest that long duration Gamma-ray Bursts are associated with bright SNe-Ic. However recent works suggest that GRBs might be produced in tight binary systems composed of a massive carbon-oxygen cores and a neutron star companion. Current estimates of the SN and GRB rates yield a ratio GRB/SNe-Ibc in the range ∼ 0.4% − 3%.

  10. SUPERNOVA NEUTRINO LIGHT CURVES AND SPECTRA FOR VARIOUS PROGENITOR...

    Office of Scientific and Technical Information (OSTI)

    FROM CORE COLLAPSE TO PROTO-NEUTRON STAR COOLING Citation Details In-Document Search Title: SUPERNOVA NEUTRINO LIGHT CURVES AND SPECTRA FOR VARIOUS PROGENITOR STARS: FROM CORE ...

  11. Multigroup Radiation Transport in Supernova Light Curve Calculations...

    Office of Scientific and Technical Information (OSTI)

    Multigroup Radiation Transport in Supernova Light Curve Calculations Even, Wesley P. Los Alamos National Laboratory; Frey, Lucille H. Los Alamos National Laboratory; Fryer,...

  12. Saul Perlmutter, Distant Supernovae, Dark Energy, and the Accelerating...

    Office of Scientific and Technical Information (OSTI)

    Saul Perlmutter, Distant Supernovae, Dark Energy, and the Accelerating Expansion of the ... studies to determine the nature of dark energy.'1 'The accelerating expansion means that ...

  13. Multigroup Radiation Transport in Supernova Light Curve Calculations...

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Technical Report: Multigroup Radiation Transport in Supernova Light Curve Calculations Citation Details In-Document Search Title: Multigroup ...

  14. Neutrino-induced nucleosynthesis in supernovae

    SciTech Connect (OSTI)

    Hayakawa, Takehito

    2012-11-12

    The neutrino-induced reactions in supernova explosions produce some rare odd-odd nuclides. We have made a new time-dependent calculation of the supernova production ratio of the long-lived isomeric state of {sup 180}Ta. This time-dependent solution is crucial for understanding the production and survival of this isotope. We find that the explicit time evolution of the synthesis of {sup 180}Ta using the available nuclear data avoids the overproduction relative to {sup 138}La for a {nu}-process neutrino temperature of 4 MeV. An unstable isotope {sup 92}Nb decays to {sup 92}Zr with a half-life of 3.47 Multiplication-Sign 10{sup 7} years. We have proposed the {nu}-process origin for {sup 92}Nb. We calculate key neutrino-induced reactions and supernova {nu}-process. Our calculated result shows that the abundance of {sup 92}Nb can be explained by the {nu}-process.

  15. Supernova Simulations from the T-6 Group at Los Alamos National...

    Office of Scientific and Technical Information (OSTI)

    Supernova Simulations from the T-6 Group at Los Alamos National Laboratory (LANL) Title: Supernova Simulations from the T-6 Group at Los Alamos National Laboratory (LANL) LANL's ...

  16. Supernova Simulations from the T-6 Group at Los Alamos National...

    Office of Scientific and Technical Information (OSTI)

    Data Explorer Search Results Supernova Simulations from the T-6 Group at Los Alamos National Laboratory (LANL) Title: Supernova Simulations from the T-6 Group at Los Alamos ...

  17. report.dvi

    Broader source: All U.S. Department of Energy (DOE) Office Webpages

    Report, "Systematic Effects in Type-1a Supernovae Surveys from Host Galaxy Spectra' PI: Michael A. Strauss, Princeton University This project explored the relationship between the physical nature of Type Ia supernovae, and the host galaxies in which they lie. Type Ia supernovae are used as a key cosmological probe: their observed brightness as a function of redshift is one of the key pieces of evidence that we live in an accelerating Universe dominated by Dark Energy. This discovery

  18. Type 1a supernovae. (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    in the Cosmos held July 27 - August 1, 2008 in Mackinac Island, MI.; Related Information: Proposed for presentation at the 10th Symposium on Nuclei in the Cosmos held July 27 - ...

  19. Confirmed: Stellar Behemoth Self-Destructs in Type IIb Supernova

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    times as massive as Earth, it accounts for 99.86 ... Because these stars are relatively rare and often obscured, ... to determine what elements were abundant on the ...

  20. Host galaxy spectra and consequences for supernova typing from...

    Office of Scientific and Technical Information (OSTI)

    ... Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States) Institut de Fsica d'Altes Energies, Universitat Autnoma de Barcelona, E-08193 ...

  1. Light Element Production in Type Ic Supernovae (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    In this kind of explosions, 6Li is produced by a fusion ... Graduate School of Science, University of Tokyo, ... evolution of galaxies 2005: New horizon of nuclear ...

  2. The core collapse supernova rate from the SDSS-II supernova survey

    SciTech Connect (OSTI)

    Taylor, Matt; Cinabro, David [Department of Physics and Astronomy, Wayne State University, Detroit, MI 48202 (United States); Dilday, Ben [Spokane, WA 99203 (United States); Galbany, Lluis [Millennium Institute of Astrophysics, Universidad de Chile, Casilla 36-D, Santiago (Chile); Gupta, Ravi R. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Kessler, R. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Marriner, John [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Nichol, Robert C. [Institute of Cosmology and Gravitation, Dennis Sciama Building, University of Portsmouth, Portsmouth PO1 2FX (United Kingdom); Richmond, Michael [School of Physics and Astronomy, Rochester Institute of Technology, Rochester, NY 14623 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Sollerman, Jesper, E-mail: cinabro@physics.wayne.edu [The Oskar Klein Centre, Department of Astronomy, AlbaNova, SE-106 91 Stockholm (Sweden)

    2014-09-10

    We use the Sloan Digital Sky Survey II Supernova Survey (SDSS-II SNS) data to measure the volumetric core collapse supernova (CCSN) rate in the redshift range (0.03 < z < 0.09). Using a sample of 89 CCSN, we find a volume-averaged rate of 1.06 0.19 10{sup 4}((h/0.7){sup 3}/(yr Mpc{sup 3})) at a mean redshift of 0.072 0.009. We measure the CCSN luminosity function from the data and consider the implications on the star formation history.

  3. An Analysis of Department of Defense Instruction 8500.2 'Information Assurance (IA) Implementation.'

    SciTech Connect (OSTI)

    Campbell, Philip LaRoche

    2012-01-01

    The Department of Defense (DoD) provides its standard for information assurance in its Instruction 8500.2, dated February 6, 2003. This Instruction lists 157 'IA Controls' for nine 'baseline IA levels.' Aside from distinguishing IA Controls that call for elevated levels of 'robustness' and grouping the IA Controls into eight 'subject areas' 8500.2 does not examine the nature of this set of controls, determining, for example, which controls do not vary in robustness, how this set of controls compares with other such sets, or even which controls are required for all nine baseline IA levels. This report analyzes (1) the IA Controls, (2) the subject areas, and (3) the Baseline IA levels. For example, this report notes that there are only 109 core IA Controls (which this report refers to as 'ICGs'), that 43 of these core IA Controls apply without variation to all nine baseline IA levels and that an additional 31 apply with variations. This report maps the IA Controls of 8500.2 to the controls in NIST 800-53 and ITGI's CoBIT. The result of this analysis and mapping, as shown in this report, serves as a companion to 8500.2. (An electronic spreadsheet accompanies this report.)

  4. Luminous blue variables and superluminous supernovae from binary mergers

    SciTech Connect (OSTI)

    Justham, Stephen; Podsiadlowski, Philipp; Vink, Jorick S. E-mail: podsi@astro.ox.ac.uk

    2014-12-01

    Evidence suggests that the direct progenitor stars of some core-collapse supernovae (CCSNe) are luminous blue variables (LBVs), perhaps including some Type II 'superluminous supernovae' (SLSNe). We examine models in which massive stars gain mass soon after the end of core hydrogen burning. These are mainly intended to represent mergers following a brief contact phase during early Case B mass transfer, but may also represent stars which gain mass in the Hertzsprung Gap or extremely late during the main-sequence phase for other reasons. The post-accretion stars spend their core helium-burning phase as blue supergiants (BSGs), and many examples are consistent with being LBVs at the time of core collapse. Other examples are yellow supergiants at explosion. We also investigate whether such post-accretion stars may explode successfully after core collapse. The final core properties of post-accretion models are broadly similar to those of single stars with the same initial mass as the pre-merger primary star. More surprisingly, when early Case B accretion does affect the final core properties, the effect appears likely to favor a successful SN explosion, i.e., to make the core properties more like those of a lower-mass single star. However, the detailed structures of these cores sometimes display qualitative differences to any single-star model we have calculated. The rate of appropriate binary mergers may match the rate of SNe with immediate LBV progenitors; for moderately optimistic assumptions we estimate that the progenitor birthrate is ?1% of the CCSN rate.

  5. Microsoft PowerPoint - IEEE IAS PES 102313.pptx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    DOE's ARRA Smart Grid Program Steve Bossart, Senior Energy Analyst IEEE IAS/PES Pittsburgh Section October 23, 2013 # Topics * OE ARRA Smart Grid Program * OE ARRA Smart Grid Progress * Results and Case Studies * Life After ARRA Smart Grid # DOE OE ARRA Smart Grid Program # American Recovery and Reinvestment Act ($4.5B) * Smart Grid Investment Grants (99 projects) - $3.4 billion Federal; $4.7 billion private sector - > 800 PMUs covering almost 100% of transmission - ~ 8000 distribution

  6. 2012 Publications Resulting from the Use of NERSC Resources

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2 2012 Publications Resulting from the Use of NERSC Resources On their Allocation Year 2013 ERCAP Request Forms Principal Investigators reported 1,925 refereed publications (published or in press) for the preceding 12 months, based on using, at least in part, NERSC resources. Aldering | Greg Scalzo et al., A Search for New Candidate Super-Chandrasekhar-mass Type Ia Supernovae in the Nearby Supernova Factory Data Set, The Astrophysical Roepke et al., Constraining Type Ia Supernova Models: SN

  7. SS 383: A NEW S-TYPE YELLOW SYMBIOTIC STAR?

    SciTech Connect (OSTI)

    Baella, N. O.; Pereira, C. B.; Miranda, L. F.

    2013-11-01

    Symbiotic stars are key objects in understanding the formation and evolution of interacting binary systems, and are probably the progenitors of Type Ia supernovae. However, the number of known symbiotic stars is much lower than predicted. We aim to search for new symbiotic stars, with particular emphasis on the S-type yellow symbiotic stars, in order to determine their total population, evolutionary timescales, and physical properties. The Two Micron All Sky Survey (2MASS) (J H) versus (H K {sub s}) color-color diagram has been previously used to identify new symbiotic star candidates and show that yellow symbiotics are located in a particular region of that diagram. Candidate symbiotic stars are selected on the basis of their locus in the 2MASS (J H) versus (H K {sub s}) diagram and the presence of H? line emission in the Stephenson and Sanduleak H? survey. This diagram separates S-type yellow symbiotic stars from the rest of the S-type symbiotic stars, allowing us to select candidate yellow symbiotics. To establish the true nature of the candidates, intermediate-resolution spectroscopy is obtained. We have identified the H? emission line source SS 383 as an S-type yellow symbiotic candidate by its position in the 2MASS color-color diagram. The optical spectrum of SS 383 shows Balmer, He I, He II, and [O III] emission lines, in combination with TiO absorption bands that confirm its symbiotic nature. The derived electron density (?10{sup 8-9} cm{sup 3}), He I emission line intensity ratios, and position in the [O III] ?5007/H? versus [O III] ?4363/H? diagram indicate that SS 383 is an S-type symbiotic star, with a probable spectral type of K7-M0 deduced for its cool component based on TiO indices. The spectral type and the position of SS 383 (corrected for reddening) in the 2MASS color-color diagram strongly suggest that SS 383 is an S-type yellow symbiotic. Our result points out that the 2MASS color-color diagram is a powerful tool in identifying new S-type

  8. Supernovae as Nuclear and Particle Physics Laboratories

    SciTech Connect (OSTI)

    Liebendoerfer, Matthias; Fischer, T.; Hempel, M.; Mezzacappa, Anthony; Pagliara, G.; Sagert, I.; Schaffner-Bielich, J.; Scheidegger, Simon; Thielemann, Friedrich-Karl W.; Whitehouse, Stuart

    2009-01-01

    In the interior of supernovae, temperatures and densities exceed the range that is easily accessible by terrestrial experiments. With the improving sensitivities of neutrino and gravitational wave detectors, the chance of obtaining observations providing a deep view into the heart of a close-by supernova explosion is steadily increasing. Based on computational models, we investigate the imprint of the nuclear equation of state on the emission of neutrinos and gravitational waves. If a QCD phase transition to quark matter occurs during the immediate postbounce accretion phase, a strong second shock front is formed at a radius of order 10 km. Neutronized hadronic outer layers of the protoneutron star fall into it, are shock-heated, and lead to a rapid acceleration of the second shock wave. As soon as this shock reduces the electron degeneracy at the neutrinospheres, a sharp second neutrino burst is emitted, dominated by electron antineutrinos. Together with the abruptly increasing mean energies of {mu}- and {tau}-neutrinos, it may serve as a clear signature of the phase transition of the protoneutron star core to a more compact state.

  9. Table 33. Oxygenated Motor Gasoline Prices by Grade, Sales Type...

    Gasoline and Diesel Fuel Update (EIA)

    - - - - - - - 1997 Average ... - - - - - - - - - - - - Subdistrict IA January ... - - - - - - - - - - - - February...

  10. The Explosion Mechanism of Core-Collapse Supernovae: Progress in Supernova Theory and Experiments

    SciTech Connect (OSTI)

    Foglizzo, Thierry; Kazeroni, Rémi; Guilet, Jérôme; Masset, Frédéric; González, Matthias; Krueger, Brendan K.; Novak, Jérôme; Faure, Julien; Martin, Noël; Blottiau, Patrick; Peres, Bruno; Durand, Gilles

    2015-03-17

    The explosion of core-collapse supernova depends on a sequence of events taking place in less than a second in a region of a few hundred kilometers at the center of a supergiant star, after the stellar core approaches the Chandrasekhar mass and collapses into a proto-neutron star, and before a shock wave is launched across the stellar envelope. Theoretical efforts to understand stellar death focus on the mechanism which transforms the collapse into an explosion. Progress in understanding this mechanism is reviewed with particular attention to its asymmetric character. We highlight a series of successful studies connecting observations of supernova remnants and pulsars properties to the theory of core-collapse using numerical simulations. The encouraging results from first principles models in axisymmetric simulations is tempered by new puzzles in 3D. The diversity of explosion paths and the dependence on the pre-collapse stellar structure is stressed, as well as the need to gain a better understanding of hydrodynamical and MHD instabilities such as SASI and neutrino-driven convection. The shallow water analogy of shock dynamics is presented as a comparative system where buoyancy effects are absent. This dynamical system can be studied numerically and also experimentally with a water fountain. Lastly, we analyse the potential of this complementary research tool for supernova theory. We also review its potential for public outreach in science museums.

  11. Fermi Large Area Telescope Observations of the Supernova Remnant...

    Office of Scientific and Technical Information (OSTI)

    Fermi Large Area Telescope Observations of the Supernova Remnant G8.7-0.1 Citation Details ... Language: English Subject: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 72 PHYSICS ...

  12. The Nearby Supernova Factory: Toward A High-Precision Spectro...

    Office of Scientific and Technical Information (OSTI)

    The goal is to acquire for each supernova and over its full life-time (more than 10 epochs) high spectro-photometric quality spectra over the extended optical range (320-1000 nm).I ...

  13. Lab helps to discover supernova ASAS-SN

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    located about 10,000 light years away in the host galaxy of the supernova. (Credit: Beijing Planetarium Jin Ma) "The grand challenge in this work is to select rare transient ...

  14. How to See the Supernova Berkeley Lab Just Discovered | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    away - than any other of its kind in a generation. ... A new supernova has been discovered near the Big Dipper. ... by the Chabot Space & Science Center on September 10 to ...

  15. THE ENGINES BEHIND SUPERNOVAE AND GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    FRYER, CHRISTOPHER LEE

    2007-01-23

    The authors review the different engines behind supernova (SNe) and gamma-ray bursts (GRBs), focusing on those engines driving explosions in massive stars: core-collapse SNe and long-duration GRBs. Convection and rotation play important roles in the engines of both these explosions. They outline the basic physics and discuss the wide variety of ways scientists have proposed that this physics can affect the supernova explosion mechanism, concluding with a review of the current status in these fields.

  16. Petascale Simulation of Magnetorotational Core-Collapse Supernovae |

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Argonne Leadership Computing Facility Magnetohydrodynamic turbulence powered by neutrino driven convection Magnetohydrodynamic turbulence powered by neutrino driven convection behind the stalled shock of a core-collapse supernova simulation. This simulation shows that the presence of rotation and weak magnetic fields dramatically impacts the development of the supernova mechanism as compared to non-rotating, non-magnetic stars. The nascent neutron star is just barely visible in the center of

  17. Three Dimensional Simulations for Core Collapse Supernovae | Argonne

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Leadership Computing Facility Three Dimensional Simulations for Core Collapse Supernovae PI Name: Anthony Mezzacappa PI Email: mezzacappaa@ornl.gov Institution: Oak Ridge National Laboratory Allocation Program: INCITE Allocation Hours at ALCF: 65 Million Year: 2013 Research Domain: Physics Core collapse supernovae are the dominant source of elements in the Universe, dominating the origin of the elements between oxygen and iron and responsible for half the elements heavier than iron. They are

  18. Neutrino flavor instabilities in a time-dependent supernova model

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abbar, Sajad; Duan, Huaiyu

    2015-10-19

    In this study, a dense neutrino medium such as that inside a core-collapse supernova can experience collective flavor conversion or oscillations because of the neutral-current weak interaction among the neutrinos. This phenomenon has been studied in a restricted, stationary supernova model which possesses the (spatial) spherical symmetry about the center of the supernova and the (directional) axial symmetry around the radial direction. Recently it has been shown that these spatial and directional symmetries can be broken spontaneously by collective neutrino oscillations. In this letter we analyze the neutrino flavor instabilities in a time-dependent supernova model. Our results show that collectivemore »neutrino oscillations start at approximately the same radius in both the stationary and time-dependent supernova models unless there exist very rapid variations in local physical conditions on timescales of a few microseconds or shorter. Our results also suggest that collective neutrino oscillations can vary rapidly with time in the regimes where they do occur which need to be studied in time-dependent supernova models.« less

  19. Pair-instability supernovae in the local universe

    SciTech Connect (OSTI)

    Whalen, Daniel J. [Zentrum fr Astronomie, Institut fr Theoretische Astrophysik, Universitt Heidelberg, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Smidt, Joseph [CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Heger, Alexander [Monash Centre for Astrophysics, Monash University, Victoria 3800 (Australia); Hirschi, Raphael [Astrophysics Group, EPSAM, University of Keele, Lennard-Jones Labs, Keele ST5 5BG (United Kingdom); Yusof, Norhasliza [Department of Physics, University of Malaysia, 50603 Kuala Lampur (Malaysia); Even, Wesley; Fryer, Chris L. [T-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Stiavelli, Massimo [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Chen, Ke-Jung [Department of Astronomy and Astrophysics, UCSC, Santa Cruz, CA 95064 (United States); Joggerst, Candace C. [XTD-3, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2014-12-10

    The discovery of 150-300 M {sub ?} stars in the Local Group and pair-instability supernova candidates at low redshifts has excited interest in this exotic explosion mechanism. Realistic light curves for pair-instability supernovae at near-solar metallicities are key to identifying and properly interpreting these events as more are found. We have modeled pair-instability supernovae of 150-500 M {sub ?} Z ? 0.1-0.4 Z {sub ?} stars. These stars lose up to 80% of their mass to strong line-driven winds and explode as bare He cores. We find that their light curves and spectra are quite different from those of Population III pair-instability explosions, which therefore cannot be used as templates for low-redshift events. Although non-zero metallicity pair-instability supernovae are generally dimmer than their Population III counterparts, in some cases they will be bright enough to be detected at the earliest epochs at which they can occur, the formation of the first galaxies at z ? 10-15. Others can masquerade as dim, short duration supernovae that are only visible in the local universe and that under the right conditions could be hidden in a wide variety of supernova classes. We also report for the first time that some pair-instability explosions can create black holes with masses of ?100 M {sub ?}.

  20. The host galaxies of fast-ejecta core-collapse supernovae (Journal...

    Office of Scientific and Technical Information (OSTI)

    The host galaxies of fast-ejecta core-collapse supernovae Citation Details In-Document Search Title: The host galaxies of fast-ejecta core-collapse supernovae Spectra of broad-lined ...

  1. The first Fermi LAT supernova remnant catalog

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Acero, F.

    2016-05-16

    To uniformly determine the properties of supernova remnants (SNRs) at high energies, we have developed the first systematic survey at energies from 1 to 100 GeV using data from the Fermi Large Area Telescope. Based on the spatial overlap of sources detected at GeV energies with SNRs known from radio surveys, we classify 30 sources as likely GeV SNRs. We also report 14 marginal associations and 245 flux upper limits. A mock catalog in which the positions of known remnants are scrambled in Galactic longitude, allows us to determine an upper limit of 22% on the number of GeV candidatesmore » falsely identified as SNRs. We have also developed a method to estimate spectral and spatial systematic errors arising from the diffuse interstellar emission model, a key component of all Galactic Fermi LAT analyses. By studying remnants uniformly in aggregate, we measure the GeV properties common to these objects and provide a crucial context for the detailed modeling of individual SNRs. Combining our GeV results with multiwavelength (MW) data, including radio, X-ray, and TeV, demonstrates the need for improvements to previously sufficient, simple models describing the GeV and radio emission from these objects. As a result, we model the GeV and MW emission from SNRs in aggregate to constrain their maximal contribution to observed Galactic cosmic rays.« less

  2. TRANSPARENT HELIUM IN STRIPPED ENVELOPE SUPERNOVAE

    SciTech Connect (OSTI)

    Piro, Anthony L.; Morozova, Viktoriya S., E-mail: piro@caltech.edu [Theoretical Astrophysics, California Institute of Technology, 1200 E. California Blvd., M/C 350-17, Pasadena, CA 91125 (United States)

    2014-09-01

    Using simple arguments based on photometric light curves and velocity evolution, we propose that some stripped envelope supernovae (SNe) show signs that a significant fraction of their helium is effectively transparent. The main pieces of evidence are the relatively low velocities with little velocity evolution, as are expected deep inside an exploding star, along with temperatures that are too low to ionize helium. This means that the helium should not contribute to the shaping of the main SN light curve, and thus the total helium mass may be difficult to measure from simple light curve modeling. Conversely, such modeling may be more useful for constraining the mass of the carbon/oxygen core of the SN progenitor. Other stripped envelope SNe show higher velocities and larger velocity gradients, which require an additional opacity source (perhaps the mixing of heavier elements or radioactive nickel) to prevent the helium from being transparent. We discuss ways in which similar analysis can provide insights into the differences and similarities between SNe Ib and Ic, which will lead to a better understanding of their respective formation mechanisms.

  3. The Explosion Mechanism of Core-Collapse Supernovae: Progress in Supernova Theory and Experiments

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Foglizzo, Thierry; Kazeroni, Rémi; Guilet, Jérôme; Masset, Frédéric; González, Matthias; Krueger, Brendan K.; Novak, Jérôme; Oertel, Micaela; Margueron, Jérôme; Faure, Julien; et al

    2015-03-17

    The explosion of core-collapse supernova depends on a sequence of events taking place in less than a second in a region of a few hundred kilometers at the center of a supergiant star, after the stellar core approaches the Chandrasekhar mass and collapses into a proto-neutron star, and before a shock wave is launched across the stellar envelope. Theoretical efforts to understand stellar death focus on the mechanism which transforms the collapse into an explosion. Progress in understanding this mechanism is reviewed with particular attention to its asymmetric character. We highlight a series of successful studies connecting observations of supernovamore » remnants and pulsars properties to the theory of core-collapse using numerical simulations. The encouraging results from first principles models in axisymmetric simulations is tempered by new puzzles in 3D. The diversity of explosion paths and the dependence on the pre-collapse stellar structure is stressed, as well as the need to gain a better understanding of hydrodynamical and MHD instabilities such as SASI and neutrino-driven convection. The shallow water analogy of shock dynamics is presented as a comparative system where buoyancy effects are absent. This dynamical system can be studied numerically and also experimentally with a water fountain. Lastly, we analyse the potential of this complementary research tool for supernova theory. We also review its potential for public outreach in science museums.« less

  4. Isovector dipole resonances in {sup 4}He and neutrino-heating in supernova

    SciTech Connect (OSTI)

    Nakayama, S.; Matsumoto, E.; Fushimi, K.; Hayami, R.; Suzuki, T.; Yamagata, T.; Akimune, H.; Ikemizu, H.; Fujiwara, M.; Hashimoto, H.; Kawase, K.; Nakanishi, K.; Oota, T.; Yosoi, M.; Greenfield, M. B.; Kudoh, T.; Sagara, K.; Tanaka, M.

    2010-06-01

    We studied transition strengths to isovector dipole resonances (GDR-1-bar , SDR-1-bar , and SDR-2-bar ) in {sup 4}He by using the {sup 4}He({sup 7}Li,{sup 7}Begamma) reaction at 455 MeV and by comparing with shell-model calculations, in order to estimate cross sections of {sup 4}He for reactions induced by neutrinos emitting from a thermalized neutrino-sphere in the type-II supernova. Excitation of the SDR was dominant in the neutrino-heating of {sup 4}He. The {sup 4}He-excitation via neutral-current reactions of nu{sub m}u{sub ,t}au and nu-bar{sub m}u{sub ,t}au was found to be one order of magnitude stronger than that via charged-current reactions of nu{sub e} and nu-bar{sub e}. The total energy-weighted cross section {sub N} for neutrino-induced neutral-current reactions on {sup 4}He was found to amount to about 1.0x10{sup -40} MeVcentre dotcm{sup 2} which is comparable to those used in the previous simulations. The neutrino-heating effect of {sup 4}He is small in the type-II supernova explosion.

  5. Neutrino probe comparisons of supernovae as a function of redshift

    SciTech Connect (OSTI)

    Fryer, Christopher Lee

    2009-01-01

    We compare aspects of supernova explosions produced in the current epoch against those produced in the first round of star formation. Although the total final mass of stars can change dramatically between these two epochs due to different mass-loss rates from winds, their cores remam very similar. The core structure is more sensitive to the stellar evolution code than it is to the amount of metals. As such, current stellar models produce supernovae from first stars that look very similar to that of stars produced in the current epoch. The neutrino signal, a powerful probe of the inner core, is identical to the few percent level for both star formation epochs. A change in the neutrino signal in the supernova population between these two star formation epochs will only arise if the initial mass function is altered.

  6. Setting the stage for circumstellar interaction in core-collapse supernovae. II. Wave-driven mass loss in supernova progenitors

    SciTech Connect (OSTI)

    Shiode, Joshua H.; Quataert, Eliot E-mail: eliot@berkeley.edu

    2014-01-01

    Supernovae (SNe) powered by interaction with circumstellar material provide evidence for intense stellar mass loss during the final years before core collapse. We have argued that during and after core neon burning, internal gravity waves excited by core convection can tap into the core fusion power and transport a super-Eddington energy flux out to the stellar envelope, potentially unbinding ?1 solar mass of material. In this work, we explore the internal conditions of SN progenitors using the MESA one-dimensional stellar evolution code in search of those most susceptible to wave-driven mass loss. We focus on simple, order of magnitude considerations applicable to a wide range of progenitors. Wave-driven mass loss during core neon and oxygen fusion happens preferentially in either lower mass (?20 solar mass zero-age main sequence) stars or massive, sub-solar metallicity stars. Roughly 20% of the SN progenitors we survey can excite 10{sup 46-48} erg of energy in waves that can potentially drive mass loss within a few months to a decade of core collapse. This energy can generate circumstellar environments with 10{sup 3}-1 solar masses reaching 100 AU before explosion. We predict a correlation between the energy associated with pre-SN mass ejection and the time to core collapse, with the most intense mass loss preferentially occurring closer to core collapse. During silicon burning, wave energy may inflate 10{sup 3}-1 solar masses of the envelope to 10-100 s of solar radii. This suggests that some nominally compact SN progenitors (Type Ibc progenitors) will have a significantly different SN shock breakout signature than traditionally assumed.

  7. File:USDA-CE-Production-GIFmaps-IA.pdf | Open Energy Information

    Open Energy Info (EERE)

    IA.pdf Jump to: navigation, search File File history File usage Iowa Ethanol Plant Locations Size of this preview: 776 600 pixels. Full resolution (1,650 1,275 pixels,...

  8. Expectations for the hard x-ray continuum and gamma-ray line...

    Office of Scientific and Technical Information (OSTI)

    x-ray continuum and gamma-ray line fluxes from the typE IA supernova SN 2014J in M82 Citation Details In-Document Search Title: Expectations for the hard x-ray continuum and ...

  9. "Title","Creator/Author","Publication Date","OSTI Identifier...

    Office of Scientific and Technical Information (OSTI)

    Report: Discovering the Nature of Dark Energy: Towards Better Distances from Type Ia Supernovae","Saurabh W. Jha","2012-10-03T04:00:00Z",1052447,"10.21721052447","DOE...

  10. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... Improved Dark Energy Constraints From 100 New CfA Supernova Type Ia Light Curves Hicken, Malcolm ; Harvard-Smithsonian Ctr. Astrophys. Harvard U. ; Wood-Vasey, W.Michael ; ...

  11. Search for: All records | Data Explorer

    Office of Scientific and Technical Information (OSTI)

    Previous studies of Type Ia supernovae ledmore to the discovery of the mysterious "dark energy" that is causing the universe to expand at an accelerating rate. To reduce the ...

  12. Pair instability supernovae of very massive population III stars

    SciTech Connect (OSTI)

    Chen, Ke-Jung; Woosley, Stan; Heger, Alexander; Almgren, Ann; Whalen, Daniel J.

    2014-09-01

    Numerical studies of primordial star formation suggest that the first stars in the universe may have been very massive. Stellar models indicate that non-rotating Population III stars with initial masses of 140-260 M {sub ☉} die as highly energetic pair-instability supernovae. We present new two-dimensional simulations of primordial pair-instability supernovae done with the CASTRO code. Our simulations begin at earlier times than previous multidimensional models, at the onset of core contraction, to capture any dynamical instabilities that may be seeded by core contraction and explosive burning. Such instabilities could enhance explosive yields by mixing hot ash with fuel, thereby accelerating nuclear burning, and affect the spectra of the supernova by dredging up heavy elements from greater depths in the star at early times. Our grid of models includes both blue supergiants and red supergiants over the range in progenitor mass expected for these events. We find that fluid instabilities driven by oxygen and helium burning arise at the upper and lower boundaries of the oxygen shell ∼20-100 s after core bounce. Instabilities driven by burning freeze out after the SN shock exits the helium core. As the shock later propagates through the hydrogen envelope, a strong reverse shock forms that drives the growth of Rayleigh-Taylor instabilities. In red supergiant progenitors, the amplitudes of these instabilities are sufficient to mix the supernova ejecta.

  13. SUPERNOVAE AND AGN DRIVEN GALACTIC OUTFLOWS

    SciTech Connect (OSTI)

    Sharma, Mahavir; Nath, Biman B. E-mail: biman@rri.res.in

    2013-01-20

    We present analytical solutions for winds from galaxies with a Navarro-Frank-White (NFW) dark matter halo. We consider winds driven by energy and mass injection from multiple supernovae (SNe), as well as momentum injection due to radiation from a central black hole. We find that the wind dynamics depends on three velocity scales: (1) v{sub *}{approx}( E-dot / 2 M-dot ){sup 1/2} describes the effect of starburst activity, with E-dot and M-dot as energy and mass injection rate in a central region of radius R; (2) v {sub .} {approx} (GM {sub .}/2R){sup 1/2} for the effect of a central black hole of mass M {sub .} on gas at distance R; and (3) v{sub s}=(GM{sub h} / 2Cr{sub s}){sup 1/2}, which is closely related to the circular speed (v{sub c} ) for an NFW halo, where r{sub s} is the halo scale radius and C is a function of the halo concentration parameter. Our generalized formalism, in which we treat both energy and momentum injection from starbursts and radiation from the central active galactic nucleus (AGN), allows us to estimate the wind terminal speed to be (4v {sup 2} {sub *} + 6({Gamma} - 1)v {sub .} {sup 2} - 4v {sup 2} {sub s}){sup 1/2}, where {Gamma} is the ratio of force due to radiation pressure to gravity of the central black hole. Our dynamical model also predicts the following: (1) winds from quiescent star-forming galaxies cannot escape from 10{sup 11.5} M {sub Sun} {<=} M{sub h} {<=} 10{sup 12.5} M {sub Sun} galaxies; (2) circumgalactic gas at large distances from galaxies should be present for galaxies in this mass range; (3) for an escaping wind, the wind speed in low- to intermediate-mass galaxies is {approx}400-1000 km s{sup -1}, consistent with observed X-ray temperatures; and (4) winds from massive galaxies with AGNs at Eddington limit have speeds {approx}> 1000 km s{sup -1}. We also find that the ratio [2v {sup 2} {sub *} - (1 - {Gamma})v {sub .} {sup 2}]/v {sup 2} {sub c} dictates the amount of gas lost through winds. Used in conjunction with

  14. SUPERNOVA 2008bk AND ITS RED SUPERGIANT PROGENITOR

    SciTech Connect (OSTI)

    Van Dyk, Schuyler D.; Elias-Rosa, Nancy [Spitzer Science Center/Caltech, Mailcode 220-6, Pasadena, CA 91125 (United States); Davidge, Tim J., E-mail: vandyk@ipac.caltech.edu, E-mail: tim.davidge@nrc.ca [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, B.C., V9E 2E7 (Canada); and others

    2012-01-15

    We have obtained limited photometric and spectroscopic data for supernova (SN) 2008bk in NGC 7793, primarily at {approx}> 150 days after explosion. We find that it is a Type II-Plateau (II-P) SN that most closely resembles the low-luminosity SN 1999br in NGC 4900. Given the overall similarity between the observed light curves and colors of SNe 2008bk and 1999br, we infer that the total visual extinction to SN 2008bk (A{sub V} = 0.065 mag) must be almost entirely due to the Galactic foreground, similar to what has been assumed for SN 1999br. We confirm the identification of the putative red supergiant (RSG) progenitor star of the SN in high-quality g'r'i' images we had obtained in 2007 at the Gemini-South 8 m telescope. Little ambiguity exists in this progenitor identification, qualifying it as the best example to date, next to the identification of the star Sk -69 Degree-Sign 202 as the progenitor of SN 1987A. From a combination of photometry of the Gemini images with that of archival, pre-SN, Very Large Telescope JHK{sub s} images, we derive an accurate observed spectral energy distribution (SED) for the progenitor. We find from nebular strong-intensity emission-line indices for several H II regions near the SN that the metallicity in the environment is likely subsolar (Z Almost-Equal-To 0.6 Z{sub Sun }). The observed SED of the star agrees quite well with synthetic SEDs obtained from model RSG atmospheres with effective temperature T{sub eff} = 3600 {+-} 50 K. We find, therefore, that the star had a bolometric luminosity with respect to the Sun of log (L{sub bol}/L{sub Sun} ) = 4.57 {+-} 0.06 and radius R{sub *} = 496 {+-} 34 R{sub Sun} at {approx}6 months prior to explosion. Comparing the progenitor's properties with theoretical massive-star evolutionary models, we conclude that the RSG progenitor had an initial mass in the range of 8-8.5 M{sub Sun }. This mass is consistent with, albeit at the low end of, the inferred range of initial masses for SN II

  15. Cosmic Rays from Supernovae Proven to Hit Earth | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Cosmic Rays from Supernovae Proven to Hit Earth Cosmic Rays from Supernovae Proven to Hit Earth March 5, 2013 - 4:40pm Addthis When stars explode, the supernovas send off shock waves like the one shown in this artist's rendition, which accelerate protons to cosmic-ray energies through a process known as Fermi acceleration. Andy Freeberg SLAC National Accelerator Laboratory Did you know? Protons make up 90 percent of the cosmic rays that hit Earth's atmosphere, triggering showers of particles

  16. Gamma-Ray Emission From Crushed Clouds in Supernova Remnants

    SciTech Connect (OSTI)

    Uchiyama, Yasunobu; Blandford, Roger D.; Funk, Stefan; Tajima, Hiroyasu; Tanaka, Takaaki; /KIPAC, Menlo Park

    2010-10-27

    It is shown that the radio and gamma-ray emission observed from newly-found 'GeV-bright' supernova remnants (SNRs) can be explained by a model, in which a shocked cloud and shock-accelerated cosmic rays (CRs) frozen in it are simultaneously compressed by the supernova blastwave as a result of formation of a radiative cloud shock. Simple reacceleration of pre-existing CRs is generally sufficient to power the observed gamma-ray emission through the decays of {pi}{sup 0}-mesons produced in hadronic interactions between high-energy protons (nuclei) and gas in the compressed-cloud layer. This model provides a natural account of the observed synchrotron radiation in SNRs W51C, W44 and IC 443 with flat radio spectral index, which can be ascribed to a combination of secondary and reaccelerated electrons and positrons.

  17. Petascale Simulation of Magnetorotational Core-Collapse Supernovae |

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Argonne Leadership Computing Facility 3D MHD simulations of a rapidly-rotating, highly-magnetized star This image is from one of our 3D MHD simulations of a rapidly-rotating, highly-magnetized star. Credit: Sean Couch Petascale Simulation of Magnetorotational Core-Collapse Supernovae PI Name: Sean Couch PI Email: smc@flash.uchicago.edu Institution: California Institute of Technology Allocation Program: INCITE Allocation Hours at ALCF: 50 Million Year: 2015 Research Domain: Physics

  18. Gravitational radiation from magnetically funneled supernova fallback onto a magnetar

    SciTech Connect (OSTI)

    Melatos, A.; Priymak, M., E-mail: amelatos@unimelb.edu.au, E-mail: m.priymak@pgrad.unimelb.edu.au [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia)

    2014-10-20

    Protomagnetars spun up to millisecond rotation periods by supernova fallback are predicted to radiate gravitational waves via hydrodynamic instabilities for ?10{sup 2} s before possibly collapsing to form a black hole. It is shown that magnetic funneling of the accretion flow (1) creates a magnetically confined polar mountain, which boosts the gravitational wave signal, and (2) 'buries' the magnetic dipole moment, delaying the propeller phase and assisting black hole formation.

  19. Saul Perlmutter, Distant Supernovae, Dark Energy, and the Accelerating

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Expansion of the Universe Saul Perlmutter, Distant Supernovae, Dark Energy, and the Accelerating Expansion of the Universe Resources with Additional Information * Awards Saul Perlmutter Photo Courtesy of Lawrence Berkeley National Laboratory 'Saul Perlmutter, an astrophysicist at the U.S. Department of Energy's Lawrence Berkeley National Laboratory and a professor of physics at the University of California at Berkeley, has won the 2011 Nobel Prize in Physics "for the discovery of the

  20. Research in nuclear astrophysics: Stellar collapse and supernovae

    SciTech Connect (OSTI)

    Lattimer, J.M.; Yahil, A.

    1992-01-01

    This progress report describes the nuclear astrophysics research activities in the Earth and Space Sciences Department at Stony Brook during the last year. Our research focused on three aspects of nuclear astrophysics: (1) the equation of state of hot, dense matter, (2) the origin of supernovae and neutron stars, (3) the early cooling epoch of neutron stars. The following contains detailed reports which summarize each completed project.

  1. GRB 020410: A Gamma-ray burst afterglow discovered by its supernova...

    Office of Scientific and Technical Information (OSTI)

    We present the discovery and monitoring of the optical transient (OT) associated with GRB ... AND RADIATION PHYSICS; AFTERGLOW; COLOR; MONITORING; TELESCOPES; TRANSIENTS GRB supernova

  2. Fermi-LAT Observation of Supernova Remnant S147 (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Fermi-LAT Observation of Supernova Remnant S147 Citation Details In-Document Search Title: ... Subject: 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 71 CLASSICAL AND QUANTUM ...

  3. Cutting-edge issues of core-collapse supernova theory

    SciTech Connect (OSTI)

    Kotake, Kei; Nakamura, Ko; Kuroda, Takami; Takiwaki, Tomoya

    2014-05-02

    Based on multi-dimensional neutrino-radiation hydrodynamic simulations, we report several cutting-edge issues about the long-veiled explosion mechanism of core-collapse supernovae (CCSNe). In this contribution, we pay particular attention to whether three-dimensional (3D) hydrodynamics and/or general relativity (GR) would or would not help the onset of explosions. By performing 3D simulations with spectral neutrino transport, we show that it is more difficult to obtain an explosion in 3D than in 2D. In addition, our results from the first generation of full general relativistic 3D simulations including approximate neutrino transport indicate that GR can foster the onset of neutrino-driven explosions. Based on our recent parametric studies using a light-bulb scheme, we discuss impacts of nuclear energy deposition behind the supernova shock and stellar rotation on the neutrino-driven mechanism, both of which have yet to be included in the self-consistent 3D supernova models. Finally we give an outlook with a summary of the most urgent tasks to extract the information about the explosion mechanisms from multi-messenger CCSN observables.

  4. woosley.pptx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Astrophysical Modeling * Cosmology - Mike Norman * Type Ia Supernovae - Stan Woosley and John Bell * Core-collapse Supernovae - (Adam Burrows), Stan Woosley, and John Bell * General Relativistic Applications - ? Physics Turbulence/resolution Radiation transport COMPUTATIONAL ASTROPHYSICS CONSORTIUM * Improve our understanding of supernovae of all types through the use of large scale computing. * Design codes for the efficient study of hydrodynamics and radiation transport on the largest, fastest

  5. ON THE PROGENITOR SYSTEM OF THE TYPE Iax SUPERNOVA 2014dt IN M61

    SciTech Connect (OSTI)

    Foley, Ryan J.; Van Dyk, Schuyler D.; Clubb, Kelsey I.; Filippenko, Alexei V.; Mauerhan, Jon C.; Miller, Adam A.; Smith, Nathan

    2015-01-10

    We present pre-explosion and post-explosion Hubble Space Telescope images of the Type Iax supernova (SN Iax) 2014dt in M61. After astrometrically aligning these images, we do not detect any stellar sources at the position of the SN in the pre-explosion images to relatively deep limits (3σ limits of M {sub F438W} > –5.0 mag and M {sub F814W} > –5.9 mag). These limits are similar to the luminosity of SN 2012Z's progenitor system (M {sub F435W} = –5.43 ± 0.15 and M {sub F814W} = –5.24 ± 0.16 mag), the only probable detected progenitor system in pre-explosion images of a SN Iax, and indeed, of any white-dwarf supernova. SN 2014dt is consistent with having a C/O white-dwarf primary/helium-star companion progenitor system, as was suggested for SN 2012Z, although perhaps with a slightly smaller or hotter donor. The data are also consistent with SN 2014dt having a low-mass red giant or main-sequence star companion. The data rule out main-sequence stars with M {sub init} ≳ 16 M {sub ☉} and most evolved stars with M {sub init} ≳ 8 M {sub ☉} as being the progenitor of SN 2014dt. Hot Wolf-Rayet stars are also allowed, but the lack of nearby bright sources makes this scenario unlikely. Because of its proximity (D = 12 Mpc), SN 2014dt is ideal for long-term monitoring, where images in ∼2 yr may detect the companion star or the luminous bound remnant of the progenitor white dwarf.

  6. A plausible (overlooked) super-luminous supernova in the Sloan digital sky survey stripe 82 data

    SciTech Connect (OSTI)

    Kostrzewa-Rutkowska, Zuzanna; Koz?owski, Szymon; Wyrzykowski, ?ukasz; Djorgovski, S. George; Mahabal, Ashish A.; Glikman, Eilat; Koposov, Sergey E-mail: simkoz@astrouw.edu.pl

    2013-12-01

    We present the discovery of a plausible super-luminous supernova (SLSN), found in the archival data of Sloan Digital Sky Survey (SDSS) Stripe 82, called PSN 000123+000504. The supernova (SN) peaked at m {sub g} < 19.4 mag in the second half of 2005 September, but was missed by the real-time SN hunt. The observed part of the light curve (17 epochs) showed that the rise to the maximum took over 30 days, while the decline time lasted at least 70 days (observed frame), closely resembling other SLSNe of SN 2007bi type. The spectrum of the host galaxy reveals a redshift of z = 0.281 and the distance modulus of ? = 40.77 mag. Combining this information with the SDSS photometry, we found the host galaxy to be an LMC-like irregular dwarf galaxy with an absolute magnitude of M{sub B} = 18.2 0.2 mag and an oxygen abundance of 12+log?[O/H]=8.30.2; hence, the SN peaked at M {sub g} < 21.3 mag. Our SLSN follows the relation for the most energetic/super-luminous SNe exploding in low-metallicity environments, but we found no clear evidence for SLSNe to explode in low-luminosity (dwarf) galaxies only. The available information on the PSN 000123+000504 light curve suggests the magnetar-powered model as a likely scenario of this event. This SLSN is a new addition to a quickly growing family of super-luminous SNe.

  7. Effects of Ion Correlations in Supernovae and Neutron Star Crusts

    SciTech Connect (OSTI)

    Caballero, O. L.; Horowitz, C. J.

    2007-10-26

    Core-collapse supernovae are some of the most energetic explosions in the Universe. During the collapse 99 % of the energy is lost by neutrino emission. The dynamics of the explosion is highly sensitive to neutrino scattering from the stellar medium. We use molecular dynamics simulations to calculate ion structure factors, neutrino-nucleus scattering cross sections, and neutrino mean free paths. We find clear differences in the neutrino mean free path when the medium is composed of a mixture of ions compared with a medium composed of a single ion species.

  8. Bolometric and UV light curves of core-collapse supernovae

    SciTech Connect (OSTI)

    Pritchard, T. A.; Roming, P. W. A.; Brown, Peter J.; Bayless, Amanda J.; Frey, Lucille H.

    2014-06-01

    The Swift UV-Optical Telescope (UVOT) has been observing core-collapse supernovae (CCSNe) of all subtypes in the UV and optical since 2005. Here we present 50 CCSNe observed with the Swift UVOT, analyzing their UV properties and behavior. Where we have multiple UV detections in all three UV filters (λ {sub c} = 1928-2600 Å), we generate early time bolometric light curves, analyze the properties of these light curves and the UV contribution to them, and derive empirical corrections for the UV-flux contribution to optical-IR based bolometric light curves.

  9. 2013 Publications Resulting from the Use of NERSC Resources

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    3 2013 Publications Resulting from the Use of NERSC Resources On their Allocation Year 2014 ERCAP Request Forms Principal Investigators reported 1,977 refereed publications (published or in press) for the preceding 12 months, based on using, at least in part, NERSC resources. Aldering , Greg "Evidence of Environmental Dependencies of Type Ia Supernovae from the Nearby Supernova Factory indicated by Local H-alpha," the Nearby Supernova Factory 2013, Astronomy and Astrophysics, accepted.

  10. Exploring the Outer Solar System with the ESSENCE Supernova Survey

    SciTech Connect (OSTI)

    Becker, A.C.; Arraki, K.; Kaib, N.A.; Wood-Vasey, W.M.; Aguilera, C.; Blackman, J.W.; Blondin, S.; Challis, P.; Clocchiatti, A.; Covarrubias, R.; Damke, G.; Davis, T.M.; Filippenko, A.V.; Foley, R.J.; Garg, A.; Garnavich, P.M.; Hicken, M.; Jha, S.; Kirshner, R.P.; Krisciunas, K.; Leibundgut, B.; /Munich, Tech. U. /UC, Berkeley /NOAO, Tucson /Washington U., Seattle, Astron. Dept. /Fermilab /Harvard-Smithsonian Ctr. Astrophys. /Harvard U. /Chile U., Santiago /Ohio State U. /Cerro-Tololo InterAmerican Obs. /Harvard U. /Baltimore, Space Telescope Sci. /Johns Hopkins U. /Australian Natl. U., Canberra /Australian Natl. U., Canberra /Cerro-Tololo InterAmerican Obs. /Munich, Tech. U. /Harvard-Smithsonian Ctr. Astrophys. /Harvard U. /Cerro-Tololo InterAmerican Obs. /Texas A-M /Cerro-Tololo InterAmerican Obs.

    2011-11-10

    We report the discovery and orbital determination of 14 trans-Neptunian objects (TNOs) from the ESSENCE Supernova Survey difference imaging data set. Two additional objects discovered in a similar search of the SDSS-II Supernova Survey database were recovered in this effort. ESSENCE repeatedly observed fields far from the solar system ecliptic (-21{sup o} < {beta} < -5{sup o}), reaching limiting magnitudes per observation of I {approx} 23.1 and R {approx} 23.7. We examine several of the newly detected objects in detail, including 2003 UC{sub 414}, which orbits entirely between Uranus and Neptune and lies very close to a dynamical region that would make it stable for the lifetime of the solar system. 2003 SS{sub 422} and 2007 TA{sub 418} have high eccentricities and large perihelia, making them candidate members of an outer class of TNOs. We also report a new member of the 'extended' or 'detached' scattered disk, 2004 VN{sub 112}, and verify the stability of its orbit using numerical simulations. This object would have been visible to ESSENCE for only {approx}2% of its orbit, suggesting a vast number of similar objects across the sky. We emphasize that off-ecliptic surveys are optimal for uncovering the diversity of such objects, which in turn will constrain the history of gravitational influences that shaped our early solar system.

  11. SN 2010mb: Direct evidence for a supernova interacting with a large amount of hydrogen-free circumstellar material

    SciTech Connect (OSTI)

    Ben-Ami, Sagi; Gal-Yam, Avishay; Rabinak, Itay; Yaron, Ofer; Arcavi, Iair; Ofek, Eran O.; Mazzali, Paolo A.; Gnat, Orly; Modjaz, Maryam; Sullivan, Mark; Bildsten, Lars; Poznanski, Dovi; Bloom, Joshua S.; Nugent, Peter E.; Horesh, Assaf; Kulkarni, Shrinivas R.; Perley, Daniel; Kasliwal, Mansi M.; Quimby, Robert; Xu, Dong

    2014-04-10

    We present our observations of SN 2010mb, a Type Ic supernova (SN) lacking spectroscopic signatures of H and He. SN 2010mb has a slowly declining light curve (LC) (∼600 days) that cannot be powered by {sup 56}Ni/{sup 56}Co radioactivity, the common energy source for Type Ic SNe. We detect signatures of interaction with hydrogen-free circumstellar material including a blue quasi-continuum and, uniquely, narrow oxygen emission lines that require high densities (∼10{sup 9} cm{sup –3}). From the observed spectra and LC, we estimate that the amount of material involved in the interaction was ∼3 M {sub ☉}. Our observations are in agreement with models of pulsational pair-instability SNe described in the literature.

  12. NUMERICAL STUDY OF THE VISHNIAC INSTABILITY IN SUPERNOVA REMNANTS

    SciTech Connect (OSTI)

    Michaut, C.; Cavet, C.; Bouquet, S. E.; Roy, F.; Nguyen, H. C.

    2012-11-10

    The Vishniac instability is thought to explain the complex structure of radiative supernova remnants in their Pressure-Driven Thin Shell (PDTS) phase after a blast wave (BW) has propagated from a central explosion. In this paper, the propagation of the BW and the evolution of the PDTS stage are studied numerically with the two-dimensional (2D) code HYDRO-MUSCL for a finite-thickness shell expanding in the interstellar medium (ISM). Special attention is paid to the adiabatic index, {gamma}, and three distinct values are taken for the cavity ({gamma}{sub 1}), the shell ({gamma}{sub 2}), and the ISM ({gamma}{sub 3}) with the condition {gamma}{sub 2} < {gamma}{sub 1}, {gamma}{sub 3}. This low value of {gamma}{sub 2} accounts for the high density in the shell achieved by a strong radiative cooling. Once the spherical background flow is obtained, the evolution of a 2D-axisymmetric perturbation is computed from the linear to the nonlinear regime. The overstable mechanism, previously demonstrated theoretically by E. T. Vishniac in 1983, is recovered numerically in the linear stage and is expected to produce and enhance anisotropies and clumps on the shock front, leading to the disruption of the shell in the nonlinear phase. The period of the increasing oscillations and the growth rate of the instability are derived from several points of view (the position of the perturbed shock front, mass fluxes along the shell, and density maps), and the most unstable mode differing from the value given by Vishniac is computed. In addition, the influence of several parameters (the Mach number, amplitude and wavelength of the perturbation, and adiabatic index) is examined and for wavelengths that are large enough compared to the shell thickness, the same conclusion arises: in the late stage of the evolution of the radiative supernova remnant, the instability is dampened and the angular initial deformation of the shock front is smoothed while the mass density becomes uniform with the

  13. COSMOLOGICAL PARAMETERS FROM SUPERNOVAE ASSOCIATED WITH GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Li, Xue; Hjorth, Jens; Wojtak, Rados?aw, E-mail: lixue@dark-cosmology.dk [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark)

    2014-11-20

    We report estimates of the cosmological parameters ? {sub m} and ?{sub ?} obtained using supernovae (SNe) associated with gamma-ray bursts (GRBs) at redshifts up to 0.606. Eight high-fidelity GRB-SNe with well-sampled light curves across the peak are used. We correct their peak magnitudes for a luminosity-decline rate relation to turn them into accurate standard candles with dispersion ? = 0.18mag. We also estimate the peculiar velocity of the low-redshift host galaxy of SN 1998bw using constrained cosmological simulations. In a flat universe, the resulting Hubble diagram leads to best-fit cosmological parameters of (?{sub m},?{sub ?})=(0.58{sub ?0.25}{sup +0.22},0.42{sub ?0.22}{sup +0.25}). This exploratory study suggests that GRB-SNe can potentially be used as standardizable candles to high redshifts to measure distances in the universe and constrain cosmological parameters.

  14. Spectrum of supernova neutrinos in ultra-pure scintillators

    SciTech Connect (OSTI)

    Lujan-Peschard, C.; Pagliaroli, G.; Vissani, F., E-mail: carolup@fisica.ugto.mx, E-mail: giulia.pagliaroli@lngs.infn.it, E-mail: francesco.vissani@lngs.infn.it [Laboratori Nazionali del Gran Sasso, INFN, Assergi (AQ) (Italy)

    2014-07-01

    There is a great interest in measuring the non-electronic component of neutrinos from core collapse supernovae by observing, for the first time, also neutral-current reactions. In order to assess the physics potential of the ultra-pure scintillators in this respect, we study the entire expected energy spectrum in the Borexino, KamLAND and SNO+ detectors. We examine the various sources of uncertainties in the expectations, and in particular, those due to specific detector features and to the relevant cross sections. We discuss the possibility to identify the different neutrino flavors, and we quantify the effect of confusion, due to other components of the energy spectrum, overlapped with the neutral-current reactions of interest.

  15. GRB 020410: A Gamma-ray burst afterglow discovered by its supernova...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: GRB 020410: A Gamma-ray burst afterglow discovered by its supernova light Citation Details In-Document Search Title: GRB 020410: A Gamma-ray burst afterglow ...

  16. Improved Dark Energy Constraints From ~ 100 New CfA Supernova...

    Office of Scientific and Technical Information (OSTI)

    useful sample of nearby SN Ia between 2.6 and 2.9 times larger than before, reducing the statistical uncertainty to the point where systematics play the largest role. ...

  17. DOE Science Showcase - Supernovae | OSTI, US Dept of Energy Office of

    Office of Scientific and Technical Information (OSTI)

    Scientific and Technical Information Supernovae Core collapse supernovae are extraordinary stellar explosions that mark the death throes of massive stars, with mass greater than eight to ten times the mass of the Sun. Stars with lesser mass may also explode if they accumulate enough mass from outside to start runaway nuclear fusion. Such explosions are the dominant source of elements in the Universe between oxygen and iron and are believed to be responsible for half of the elements heavier

  18. Recombining plasma in the gamma-ray-emitting mixed-morphology supernova remnant 3C 391

    SciTech Connect (OSTI)

    Ergin, T.; Sezer, A.; Saha, L.; Majumdar, P.; Chatterjee, A.; Bayirli, A.; Ercan, E. N.

    2014-07-20

    A group of middle-aged mixed-morphology (MM) supernova remnants (SNRs) interacting with molecular clouds (MCs) has been discovered to be strong GeV gamma-ray emitters by the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope (Fermi-LAT). The recent observations of the Suzaku X-ray satellite have revealed that some of these interacting gamma-ray-emitting SNRs, such as IC443, W49B, W44, and G359.1-0.5, have overionized plasmas. 3C 391 (G31.9+0.0) is another Galactic MM SNR interacting with MCs. It was observed in GeV gamma rays by Fermi-LAT as well as in the 0.3-10.0 keV X-ray band by Suzaku. In this work, 3C 391 was detected in GeV gamma rays with a significance of ?18? and we showed that the GeV emission is point-like in nature. The GeV gamma-ray spectrum was shown to be best explained by the decay of neutral pions assuming that the protons follow a broken power-law distribution. We revealed radiative recombination structures of silicon and sulfur from 3C 391 using Suzaku data. In this paper, we discuss the possible origin of this type of radiative plasma and hadronic gamma rays.

  19. HFPK 334: An unusual supernova remnant in the Small Magellanic Cloud

    SciTech Connect (OSTI)

    Crawford, E. J.; Filipović, M. D.; McEntaffer, R. L.; Brantseg, T.; Heitritter, K.; Roper, Q.; Haberl, F.; Urošević, D.

    2014-11-01

    We present new Australia Telescope Compact Array radio-continuum and XMM-Newton/Chandra X-ray Observatory observations of the unusual supernova remnant (SNR) HFPK 334 in the Small Magellanic Cloud (SMC). The remnant follows a shell-type morphology in the radio continuum and has a size of ∼20 pc at the SMC distance. The X-ray morphology is similar; however, we detect a prominent point source close to the center of the SNR exhibiting a spectrum with a best-fit power law with a photon index of Γ = 2.7 ± 0.5. This central point source is most likely a background object and cannot be directly associated with the remnant. The high temperature, nonequilibrium conditions in the diffuse region suggest that this gas has been recently shocked and points toward a younger SNR with an age of ≲ 1800 yr. With an average radio spectral index of α = –0.59 ± 0.09, we find that an equipartition magnetic field for the remnant is ∼90 μG, a value typical of younger SNRs in low-density environments. Also, we report the detection of scattered radio polarization across the remnant at 20 cm, with a peak fractional polarization level of 25% ± 5%.

  20. Class I methanol (CH{sub 3}OH) maser conditions near supernova remnants

    SciTech Connect (OSTI)

    McEwen, Bridget C.; Pihlstrm, Ylva M.; Sjouwerman, Lornt O.

    2014-10-01

    We present results from calculations of the physical conditions necessary for the occurrence of 36.169 (4{sub 1}-3{sub 0} E), 44.070 (7{sub 0}-6{sub 1} A {sup +}), 84.521 (5{sub 1}-4{sub 0} E), and 95.169 (8{sub 0}-7{sub 1} A {sup +}) GHz methanol (CH{sub 3}OH) maser emission lines near supernova remnants (SNRs), using the MOLPOP-CEP program. The calculations show that given a sufficient methanol abundance, methanol maser emission arises over a wide range of densities and temperatures, with optimal conditions at n ? 10{sup 4}-10{sup 6} cm{sup 3} and T > 60 K. The 36 GHz and 44 GHz transitions display more significant maser optical depths compared to the 84 GHz and 95 GHz transitions over the majority of physical conditions. It is also shown that line ratios are an important and applicable probe of the gas conditions. The line ratio changes are largely a result of the E-type transitions becoming quenched faster at increasing densities. The modeling results are discussed using recent observations of CH{sub 3}OH and hydroxyl (OH) masers near the SNRs G1.40.1, W28, and Sgr A East.

  1. A BLUE POINT SOURCE AT THE LOCATION OF SUPERNOVA 2011DH

    SciTech Connect (OSTI)

    Folatelli, Gastn; Bersten, Melina C.; Nomoto, Ken'ichi; Quimby, Robert M.; Benvenuto, Omar G.; Maeda, Keiichi; Nozawa, Takaya

    2014-10-01

    We present Hubble Space Telescope (HST) observations of the field of the Type IIb supernova (SN) 2011dh in M51 performed at ?1161 rest-frame days after explosion using the Wide Field Camera 3 and near-UV filters F225W and F336W. A star-like object is detected in both bands and the photometry indicates it has negative (F225W F336W) color. The observed object is compatible with the companion of the now-vanished yellow supergiant progenitor predicted in interacting binary models. We consider it unlikely that the SN is undergoing strong interaction and thus estimate that it makes a small contribution to the observed flux. The possibilities of having detected an unresolved light echo or an unrelated object are briefly discussed and judged unlikely. Adopting a possible range of extinction by dust, we constrain parameters of the proposed binary system. In particular, the efficiency of mass accretion onto the binary companion must be below 50%, if no significant extinction is produced by newly formed dust. Further multiband observations are required in order to confirm the identification of the object as the companion star. If confirmed, the companion star would already be dominant in the UV-optical regime, so it would readily provide a unique opportunity to perform a detailed study of its properties.

  2. Fe-rich ejecta in the supernova remnant G352.70.1 with Suzaku

    SciTech Connect (OSTI)

    Sezer, A.; Gk, F.

    2014-07-20

    In this work, we present results from a ?201.6 ks observation of G352.70.1 using the X-ray Imaging Spectrometer on board Suzaku X-ray Observatory. The X-ray emission from the remnant is well described by two-temperature thermal models of non-equilibrium ionization with variable abundances with a column density of N{sub H} ? 3.3 10{sup 22} cm{sup 2}. The soft component is characterized by an electron temperature of kT{sub e} ? 0.6 keV, an ionization timescale of ? ? 3.4 10{sup 11} cm{sup 3} s, and enhanced Si, S, Ar, and Ca abundances. The hard component has kT{sub e} ? 4.3 keV, ? ? 8.8 10{sup 9} cm{sup 3} s, and enhanced Fe abundance. The elemental abundances of Si, S, Ar, Ca, and Fe are found to be significantly higher than the solar values that confirm the presence of ejecta. We detected strong Fe K-shell emission and determined its origin to be the ejecta for the first time. The detection of Fe ejecta with a lower ionization timescale favors a Type Ia origin for this remnant.

  3. CAN STELLAR MIXING EXPLAIN THE LACK OF TYPE Ib SUPERNOVAE IN...

    Office of Scientific and Technical Information (OSTI)

    Country of Publication: United States Language: English Subject: 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALGORITHMS; CONVECTION; COSMIC GAMMA BURSTS; HELIUM; MIXING; SPECTRA; ...

  4. Type IIb supernova SN 2011dh: Spectra and photometry from the...

    Office of Scientific and Technical Information (OSTI)

    ... Authors: Marion, G. H. ; Kirshner, Robert P. ; Foley, Ryan J. ; Berlind, Perry ; Bieryla, Allyson ; Calkins, Michael L. ; Challis, Peter ; Chornock, Ryan ; Esquerdo, Gilbert A. ; ...

  5. ON THE PROGENITOR SYSTEM OF THE TYPE Iax SUPERNOVA 2014dt IN...

    Office of Scientific and Technical Information (OSTI)

    Authors: Foley, Ryan J. 1 ; Van Dyk, Schuyler D. 2 ; Jha, Saurabh W. 3 ; Clubb, Kelsey I. ; Filippenko, Alexei V. ; Mauerhan, Jon C. 4 ; Miller, Adam A. 5 ; Smith, Nathan ...

  6. High Statistics Study of Nearby Type 1a Supernovae. QUEST Camera...

    Office of Scientific and Technical Information (OSTI)

    Close Cite: Bibtex Format Close 0 pages in this document matching the terms "" Search For Terms: Enter terms in the toolbar above to search the full text of this document for ...

  7. Inverse Compton Emission from Galactic Supernova Remnants: Effect of the Interstellar Radiation Field

    SciTech Connect (OSTI)

    Porter, Troy A.; Moskalenko, Igor V.; Strong, Andrew W.; /Garching, Max Planck Inst., MPE

    2006-08-01

    The evidence for particle acceleration in supernova shells comes from electrons whose synchrotron emission is observed in radio and X-rays. Recent observations by the HESS instrument reveal that supernova remnants also emit TeV {gamma}-rays; long awaited experimental evidence that supernova remnants can accelerate cosmic rays up to the ''knee'' energies. Still, uncertainty exists whether these {gamma}-rays are produced by electrons via inverse Compton scattering or by protons via {pi}{sup 0}-decay. The multi-wavelength spectra of supernova remnants can be fitted with both mechanisms, although a preference is often given to {pi}{sup 0}-decay due to the spectral shape at very high energies. A recent study of the interstellar radiation field indicates that its energy density, especially in the inner Galaxy, is higher than previously thought. In this paper we evaluate the effect of the interstellar radiation field on the inverse Compton emission of electrons accelerated in a supernova remnant located at different distances from the Galactic Centre. We show that contribution of optical and infra-red photons to the inverse Compton emission may exceed the contribution of cosmic microwave background and in some cases broaden the resulted {gamma}-ray spectrum. Additionally, we show that if a supernova remnant is located close to the Galactic Centre its {gamma}-ray spectrum will exhibit a ''universal'' cutoff at very high energies due to the Klein-Nishina effect and not due to the cut-off of the electron spectrum. As an example, we apply our calculations to the supernova remnants RX J1713.7-3946 and G0.9+0.1 recently observed by HESS.

  8. PROBING INTERSTELLAR DUST WITH INFRARED ECHOES FROM THE Cas A SUPERNOVA

    SciTech Connect (OSTI)

    Vogt, Frederic P. A.; Besel, Marc-Andre; Krause, Oliver; Dullemond, Cornelis P.

    2012-05-10

    We present the analysis of an Infrared Spectrograph 5-38 {mu}m spectrum and Multiband Imaging Photometer for Spitzer photometric measurements of an infrared echo near the Cassiopeia A (Cas A) supernova (SN) remnant observed with the Spitzer Space Telescope. We have modeled the recorded echo accounting for polycyclic aromatic hydrocarbons (PAHs), quantum-heated carbon and silicate grains, as well as thermal carbon and silicate particles. Using the fact that optical light-echo spectroscopy has established that Cas A originated from a Type IIb SN explosion showing an optical spectrum remarkably similar to the prototypical Type IIb SN 1993J, we use the latter to construct template data input for our simulations. We are then able to reproduce the recorded infrared echo spectrum by combining the emission of dust heated by the UV burst produced at the shock breakout after the core-collapse and dust heated by optical light emitted near the visual maximum of the SN light curve, where the UV burst and optical light curve characteristics are based on SN 1993J. We find a mean density of {approx}680 H cm{sup -3} for the echo region, with a size of a few light years across. We also find evidence of dust processing in the form of a lack of small PAHs with less than {approx}300 carbon atoms, consistent with a scenario of PAHs destruction by the UV burst via photodissociation at the estimated distance of the echo region from Cas A. Furthermore, our simulations suggest that the weak 11 {mu}m features of our recorded infrared echo spectrum are consistent with a strong dehydrogenated state of the PAHs. This exploratory study highlights the potential of investigating dust processing in the interstellar medium through infrared echoes.

  9. PROBING SHOCK BREAKOUT AND PROGENITORS OF STRIPPED-ENVELOPE SUPERNOVAE THROUGH THEIR EARLY RADIO EMISSIONS

    SciTech Connect (OSTI)

    Maeda, Keiichi

    2013-01-01

    We study properties of early radio emission from stripped-envelope supernovae (SNe; those of Type IIb/Ib/Ic). We suggest there is a sub-class of stripped-envelope SNe based on their radio properties, including the optically well-studied Type Ic SNe (SNe Ic) 2002ap and 2007gr, showing a rapid rise to a radio peak within {approx}10 days and reaching a low luminosity (at least an order of magnitude fainter than a majority of SNe IIb/Ib/Ic). They show a decline after the peak that is shallower than that of other stripped-envelope SNe while their spectral index is similar. We show that all these properties are naturally explained if the circumstellar material (CSM) density is low and therefore the forward shock is expanding into the CSM without deceleration. Since the forward shock velocity in this situation, as estimated from the radio properties, still records the maximum velocity of the SN ejecta following the shock breakout, observing these SNe in radio wavelengths provides new diagnostics on the nature of both the breakout and the progenitor which otherwise require a quite rapid follow-up in other wavelengths. The inferred post-shock breakout velocities of SNe Ic 2002ap and 2007gr are sub-relativistic, {approx}0.3c. These are higher than that inferred for SN II 1987A, in line with suggested compact progenitors. However, these are lower than expected for a Wolf-Rayet (W-R) progenitor. It may reflect an as yet unresolved nature of the progenitors just before the explosion, and we suggest that the W-R progenitor envelopes might have been inflated which could quickly reduce the maximum ejecta velocity from the initial shock breakout velocity.

  10. THE RED SUPERGIANT PROGENITOR OF SUPERNOVA 2012aw (PTF12bvh) IN MESSIER 95

    SciTech Connect (OSTI)

    Van Dyk, Schuyler D. [Spitzer Science Center/Caltech, Mailcode 220-6, Pasadena, CA 91125 (United States); Cenko, S. Bradley; Filippenko, Alexei V., E-mail: vandyk@ipac.caltech.edu, E-mail: cenko@berkeley.edu, E-mail: afilippenko@berkeley.edu [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); and others

    2012-09-10

    We report on the direct detection and characterization of the probable red supergiant (RSG) progenitor of the intermediate-luminosity Type II-Plateau (II-P) supernova (SN) 2012aw in the nearby (10.0 Mpc) spiral galaxy Messier 95 (M95; NGC 3351). We have identified the star in both Hubble Space Telescope images of the host galaxy, obtained 17-18 yr prior to the explosion, and near-infrared ground-based images, obtained 6-12 yr prior to the SN. The luminous supergiant showed evidence for substantial circumstellar dust, manifested as excess line-of-sight extinction. The effective total-to-selective ratio of extinction to the star was R'{sub V} Almost-Equal-To 4.35, which is significantly different from that of diffuse interstellar dust (i.e., R{sub V} = 3.1), and the total extinction to the star was therefore, on average, A{sub V} Almost-Equal-To 3.1 mag. We find that the observed spectral energy distribution for the progenitor star is consistent with an effective temperature of 3600 K (spectral type M3), and that the star therefore had a bolometric magnitude of -8.29. Through comparison with recent theoretical massive-star evolutionary tracks we can infer that the RSG progenitor had an initial mass 15 {approx}< M{sub ini}(M{sub Sun }) < 20. Interpolating by eye between the available tracks, we surmise that the star had initial mass {approx}17-18 M{sub Sun }. The circumstellar dust around the progenitor must have been destroyed in the explosion, as the visual extinction to the SN is found to be low (A{sub V} = 0.24 mag with R{sub V} = 3.1).

  11. Cosmic ray acceleration at perpendicular shocks in supernova remnants

    SciTech Connect (OSTI)

    Ferrand, Gilles; Danos, Rebecca J.; Shalchi, Andreas; Safi-Harb, Samar; Edmon, Paul; Mendygral, Peter

    2014-09-10

    Supernova remnants (SNRs) are believed to accelerate particles up to high energies through the mechanism of diffusive shock acceleration (DSA). Except for direct plasma simulations, all modeling efforts must rely on a given form of the diffusion coefficient, a key parameter that embodies the interactions of energetic charged particles with magnetic turbulence. The so-called Bohm limit is commonly employed. In this paper, we revisit the question of acceleration at perpendicular shocks, by employing a realistic model of perpendicular diffusion. Our coefficient reduces to a power law in momentum for low momenta (of index ?), but becomes independent of the particle momentum at high momenta (reaching a constant value ?{sub ?} above some characteristic momentum p {sub c}). We first provide simple analytical expressions of the maximum momentum that can be reached at a given time with this coefficient. Then we perform time-dependent numerical simulations to investigate the shape of the particle distribution that can be obtained when the particle pressure back-reacts on the flow. We observe that for a given index ? and injection level, the shock modifications are similar for different possible values of p {sub c}, whereas the particle spectra differ markedly. Of particular interest, low values of p {sub c} tend to remove the concavity once thought to be typical of non-linear DSA, and result in steep spectra, as required by recent high-energy observations of Galactic SNRs.

  12. Stochastic gravitational-wave background from cosmological supernovae

    SciTech Connect (OSTI)

    Buonanno, Alessandra; Sigl, Guenter; Raffelt, Georg G.; Janka, Hans-Thomas; Mueller, Ewald

    2005-10-15

    Based on new developments in the understanding of supernovae (SNe) as gravitational-wave (GW) sources we estimate the GW background from all cosmic SNe. For a broad range of frequencies around 1 Hz, this background is crudely comparable to the GW background expected from standard inflationary models. While our estimate remains uncertain within several orders of magnitude, the SN GW background may become detectable by second-generation space-based interferometers such as the proposed Big Bang Observatory (BBO). By the same token, the SN GWs may become a foreground for searches of the inflationary GWs, in particular, for sub-Hz frequencies where the SN background is Gaussian and where the BBO will be most sensitive. SN simulations lasting far beyond the usual cutoff of about 1 s are needed for more robust predictions in the sub-Hz frequency band. An even larger GW background can arise from a hypothetical early population of massive stars, although their GW source strength as well as their abundance are currently poorly understood.

  13. Supernova Simulations with Boltzmann Neutrino Transport: A Comparison of Methods

    SciTech Connect (OSTI)

    Liebendoerfer, M.; Rampp, M.; Janka, H.-Th.; Mezzacappa, Anthony

    2005-02-01

    Accurate neutrino transport has been built into spherically symmetric simulations of stellar core collapse and postbounce evolution. The results of such simulations agree that spherically symmetric models with standard microphysical input fail to explode by the delayed, neutrino-driven mechanism. Independent groups implemented fundamentally different numerical methods to tackle the Boltzmann neutrino transport equation. Here we present a direct and detailed comparison of such neutrino radiation-hydrodynamics simulations for two codes, AGILE-BOLTZTRAN of the Oak Ridge-Basel group and VERTEX of the Garching group. The former solves the Boltzmann equation directly by an implicit, general relativistic discrete-angle method on the adaptive grid of a conservative implicit hydrodynamics code with second-order TVD advection. In contrast, the latter couples a variable Eddington factor technique with an explicit, moving-grid, conservative high-order Riemann solver with important relativistic effects treated by an effective gravitational potential. The presented study is meant to test our neutrino radiation-hydrodynamics implementations and to provide a data basis for comparisons and verifications of supernova codes to be developed in the future. Results are discussed for simulations of the core collapse and postbounce evolution of a 13 M{sub {circle_dot}} star with Newtonian gravity and a 15 M{sub {circle_dot}} star with relativistic gravity.

  14. Exploiting the neutronization burst of a galactic supernova

    SciTech Connect (OSTI)

    Kachelriess, M.; Tomas, R.; Buras, R.; Janka, H.-Th.; Marek, A.; Rampp, M.

    2005-03-15

    One of the robust features found in simulations of core-collapse supernovae (SNe) is the prompt neutronization burst, i.e., the first {approx}25 milliseconds after bounce when the SN emits with very high luminosity mainly {nu}{sub e} neutrinos. We examine the dependence of this burst on variations in the input of current SN models and find that recent improvements of the electron capture rates as well as uncertainties in the nuclear equation of state or a variation of the progenitor mass have only little effect on the signature of the neutronization peak in a megaton water Cherenkov detector for different neutrino mixing schemes. We show that exploiting the time structure of the neutronization peak allows one to identify the case of a normal mass hierarchy and large 13-mixing angle {theta}{sub 13}, where the peak is absent. The robustness of the predicted total event number in the neutronization burst makes a measurement of the distance to the SN feasible with a precision of about 5%, even in the likely case that the SN is optically obscured.

  15. EFFECTS OF RESISTIVITY ON MAGNETIZED CORE-COLLAPSE SUPERNOVAE

    SciTech Connect (OSTI)

    Sawai, H.; Suzuki, H.; Yamada, S.; Kotake, K.

    2013-02-10

    We studied the role of turbulent resistivity in the core-collapse of a strongly magnetized massive star, carrying out two-dimensional resistive-MHD simulations. Three cases with different initial strengths of magnetic field and rotation are investigated: (1) a strongly magnetized rotating core, (2) a moderately magnetized rotating core, and (3) a very strongly magnetized non-rotating core. In each case, one ideal-MHD model and two resistive-MHD models are computed. As a result of these computations, each model shows an eruption of matter assisted by magnetic acceleration (and also by centrifugal acceleration in the rotating cases). We found that resistivity attenuates the explosion in cases 1 and 2, while it enhances the explosion in case 3. We also found that in the rotating cases, the main mechanisms for the amplification of a magnetic field in the post-bounce phase are an outward advection of the magnetic field and a twisting of poloidal magnetic field lines by differential rotation, which are somewhat dampened down with the presence of resistivity. Although magnetorotational instability seems to occur in the rotating models, it plays only a minor role in magnetic field amplification. Another impact of resistivity is that on the aspect ratio. In the rotating cases, a large aspect ratio of the ejected matter, >2.5, attained in an ideal-MHD model is reduced to some extent in a resistive model. These results indicate that resistivity possibly plays an important role in the dynamics of strongly magnetized supernovae.

  16. Off-center observers versus supernovae in inhomogeneous pressure universes

    SciTech Connect (OSTI)

    Balcerzak, Adam; Dabrowski, Mariusz P.; Denkiewicz, Tomasz [Institute of Physics, University of Szczecin, Wielkopolska 15, 70-451 Szczecin (Poland)

    2014-09-10

    Exact luminosity distance and apparent magnitude formulae are applied to the Union2 557 supernovae sample in order to constrain the possible position of an observer outside of the center of symmetry in spherically symmetric inhomogeneous pressure Stephani universes, which are complementary to inhomogeneous density Lematre-Tolman-Bondi (LTB) void models. Two specific models are investigated. The first allows a barotropic equation of state at the center of symmetry without the need to specify a scale factor function (model IIA). The second has no barotropic equation of state at the center, but has an explicit dust-like scale factor evolution (model IIB). It is shown that even at 3? CL, an off-center observer cannot be further than about 4.4 Gpc away from the center of symmetry, which is comparable to the reported size of a void in LTB models with the most likely value of the distance from the center at about 341 Mpc for model IIA and 68 Mpc for model IIB. The off-center observer cannot be farther away from the center than about 577 Mpc for model IIB at 3? CL. It is determined that the best-fit parameters which characterize inhomogeneity are ?{sub inh} = 0.77 (dimensionless: model IIA) and ? = 7.31 10{sup 9} (s km{sup 1}){sup 2/3} Mpc{sup 4/3} (model IIB).

  17. Gamma-ray burst supernovae as standardizable candles

    SciTech Connect (OSTI)

    Cano, Z., E-mail: zewcano@gmail.com [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Reykjavik (Iceland)

    2014-10-20

    A long-duration gamma-ray burst (GRB) marks the violent end of a massive star. GRBs are rare in the universe, and their progenitor stars are thought to possess unique physical properties such as low metal content and rapid rotation, while the supernovae (SNe) that are associated with GRBs are expected to be highly aspherical. To date, it has been unclear whether GRB-SNe could be used as standardizable candles, with contrasting conclusions found by different teams. In this paper, I present evidence that GRB-SNe have the potential to be used as standardizable candles and show that a statistically significant relation exists between the brightness and width of their decomposed light curves relative to a template SN. Every single nearby spectroscopically identified GRB-SN for which the rest frame and host contributions have been accurately determined follows this relation. Additionally, it is shown that not only GRB-SNe, but perhaps all SNe whose explosions are powered by a central engine may eventually be used as a standardizable candle. Finally, I suggest that the use of GRB-SNe as standardizable candles likely arises from a combination of the viewing angle and similar explosion geometry in each event, the latter of which is influenced by the explosion mechanism of GRB-SNe.

  18. Two-dimensional simulations of pulsational pair-instability supernovae

    SciTech Connect (OSTI)

    Chen, Ke-Jung; Woosley, Stan [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Heger, Alexander [Monash Centre for Astrophysics, Monash University, Melbourne, Victoria 3800 (Australia); Almgren, Ann [Center for Computational Sciences and Engineering, Lawrence Berkeley National Lab, Berkeley, CA 94720 (United States); Whalen, Daniel J., E-mail: kchen@ucolick.org [T-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2014-09-01

    Massive stars that end their lives with helium cores in the range of 35-65 M {sub ?} are known to produce repeated thermonuclear outbursts due to a recurring pair-instability. In some of these events, solar masses of material are ejected in repeated outbursts of several 10{sup 50} erg each. Collisions between these shells can sometimes produce very luminous transients that are visible from the edge of the observable universe. Previous one-dimensional (1D) studies of these events produce thin, high-density shells as one ejection plows into another. Here, in the first multi-dimensional simulations of these collisions, we show that the development of a Rayleigh-Taylor instability truncates the growth of the high-density spike and drives mixing between the shells. The progenitor is a 110 M {sub ?} solar-metallicity star that was shown in earlier work to produce a superluminous supernova. The light curve of this more realistic model has a peak luminosity and duration that are similar to those of 1D models but a structure that is smoother.

  19. Numeric spectral radiation hydrodynamic calculations of supernova shock breakouts

    SciTech Connect (OSTI)

    Sapir, Nir; Halbertal, Dorri

    2014-12-01

    We present here an efficient numerical scheme for solving the non-relativistic one-dimensional radiation-hydrodynamics equations including inelastic Compton scattering, which is not included in most codes and is crucial for solving problems such as shock breakout. The devised code is applied to the problems of a steady-state planar radiation mediated shock (RMS) and RMS breakout from a stellar envelope. The results are in agreement with those of a previous work on shock breakout, in which Compton equilibrium between matter and radiation was assumed and the 'effective photon' approximation was used to describe the radiation spectrum. In particular, we show that the luminosity and its temporal dependence, the peak temperature at breakout, and the universal shape of the spectral fluence derived in this earlier work are all accurate. Although there is a discrepancy between the spectral calculations and the effective photon approximation due to the inaccuracy of the effective photon approximation estimate of the effective photon production rate, which grows with lower densities and higher velocities, the difference in peak temperature reaches only 30% for the most discrepant cases of fast shocks in blue supergiants. The presented model is exemplified by calculations for supernova 1987A, showing the detailed evolution of the burst spectrum. The incompatibility of the stellar envelope shock breakout model results with observed properties of X-ray flashes (XRFs) and the discrepancy between the predicted and observed rates of XRFs remain unexplained.

  20. Supernovae with two peaks in the optical light curve and the signature of progenitors with low-mass extended envelopes

    SciTech Connect (OSTI)

    Nakar, Ehud; Piro, Anthony L.

    2014-06-20

    Early observations of supernova light curves are powerful tools for shedding light on the pre-explosion structures of their progenitors and their mass-loss histories just prior to explosion. Some core-collapse supernovae that are detected during the first days after the explosion prominently show two peaks in the optical bands, including the R and I bands, where the first peak appears to be powered by the cooling of shocked surface material and the second peak is clearly powered by radioactive decay. Such light curves have been explored in detail theoretically for SN 1993J and 2011dh, where it was found that they may be explained by progenitors with extended, low-mass envelopes. Here, we generalize these results. We first explore whether any double-peaked light curve of this type can be generated by a progenitor with a 'standard' density profile, such as a red supergiant or a Wolf-Rayet star. We show that a standard progenitor (1) cannot produce a double-peaked light curve in the R and I bands and (2) cannot exhibit a fast drop in the bolometric luminosity as is seen after the first peak. We then explore the signature of a progenitor with a compact core surrounded by extended, low-mass material. This may be a hydrostatic low-mass envelope or material ejected just prior to the explosion. We show that it naturally produces both of these features. We use this result to provide simple formulae to estimate (1) the mass of the extended material from the time of the first peak, (2) the extended material radius from the luminosity of the first peak, and (3) an upper limit on the core radius from the luminosity minimum between the two peaks.

  1. THE ANGULAR MOMENTA OF NEUTRON STARS AND BLACK HOLES AS A WINDOW ON SUPERNOVAE

    SciTech Connect (OSTI)

    Miller, J. M.; Miller, M. C.; Reynolds, C. S.

    2011-04-10

    It is now clear that a subset of supernovae displays evidence for jets and is observed as gamma-ray bursts (GRBs). The angular momentum distribution of massive stellar endpoints provides a rare means of constraining the nature of the central engine in core-collapse explosions. Unlike supermassive black holes, the spin of stellar-mass black holes in X-ray binary systems is little affected by accretion and accurately reflects the spin set at birth. A modest number of stellar-mass black hole angular momenta have now been measured using two independent X-ray spectroscopic techniques. In contrast, rotation-powered pulsars spin down over time, via magnetic braking, but a modest number of natal spin periods have now been estimated. For both canonical and extreme neutron star parameters, statistical tests strongly suggest that the angular momentum distributions of black holes and neutron stars are markedly different. Within the context of prevalent models for core-collapse supernovae, the angular momentum distributions are consistent with black holes typically being produced in GRB-like supernovae with jets and with neutron stars typically being produced in supernovae with too little angular momentum to produce jets via magnetohydrodynamic processes. It is possible that neutron stars are with high spin initially and rapidly spun down shortly after the supernova event, but the available mechanisms may be inconsistent with some observed pulsar properties.

  2. Spallation Model for the Titanium-Rich Supernova Remnant Cassiopeia A

    SciTech Connect (OSTI)

    Ouyed, Rachid; Leahy, Denis; Ouyed, Amir; Jaikumar, Prashanth

    2011-10-07

    Titanium-rich subluminous supernovae are rare and challenge current SN nucleosynthesis models. We present a model in which ejecta from a standard supernova is impacted by a second explosion of the neutron star (a quark nova), resulting in spallation reactions that lead to {sup 56}Ni destruction and {sup 44}Ti creation under the right conditions. Basic calculations of the spallation products shows that a delay between the two explosions of {approx}5 days reproduces the observed abundance of {sup 44}Ti in Cas A and explains its low luminosity as a result of the destruction of {sup 56}Ni. Our results could have important implications for light curves of subluminous as well as superluminous supernovae.

  3. SUPERNOVA REMNANT KES 17: AN EFFICIENT COSMIC RAY ACCELERATOR INSIDE A MOLECULAR CLOUD

    SciTech Connect (OSTI)

    Gelfand, Joseph D.; Castro, Daniel; Slane, Patrick O.; Temim, Tea; Hughes, John P.; Rakowski, Cara E-mail: cara.rakowski@gmail.com

    2013-11-10

    The supernova remnant Kes 17 (SNR G304.6+0.1) is one of a few but growing number of remnants detected across the electromagnetic spectrum. In this paper, we analyze recent radio, X-ray, and γ-ray observations of this object, determining that efficient cosmic ray acceleration is required to explain its broadband non-thermal spectrum. These observations also suggest that Kes 17 is expanding inside a molecular cloud, though our determination of its age depends on whether thermal conduction or clump evaporation is primarily responsible for its center-filled thermal X-ray morphology. Evidence for efficient cosmic ray acceleration in Kes 17 supports recent theoretical work concluding that the strong magnetic field, turbulence, and clumpy nature of molecular clouds enhance cosmic ray production in supernova remnants. While additional observations are needed to confirm this interpretation, further study of Kes 17 is important for understanding how cosmic rays are accelerated in supernova remnants.

  4. The host galaxies of fast-ejecta core-collapse supernovae

    SciTech Connect (OSTI)

    Kelly, Patrick L.; Filippenko, Alexei V.; Modjaz, Maryam; Kocevski, Daniel

    2014-07-01

    Spectra of broad-lined Type Ic supernovae (SNe Ic-BL), the only kind of SN observed at the locations of long-duration gamma-ray bursts (LGRBs), exhibit wide features indicative of high ejecta velocities (?0.1c). We study the host galaxies of a sample of 245 low-redshift (z < 0.2) core-collapse SNe, including 17 SNe Ic-BL, discovered by galaxy-untargeted searches, and 15 optically luminous and dust-obscured z < 1.2 LGRBs. We show that, in comparison with Sloan Digital Sky Survey galaxies having similar stellar masses, the hosts of low-redshift SNe Ic-BL and z < 1.2 LGRBs have high stellar mass and star formation rate densities. Core-collapse SNe having typical ejecta velocities, in contrast, show no preference for such galaxies. Moreover, we find that the hosts of SNe Ic-BL, unlike those of SNe Ib/Ic and SNe II, exhibit high gas velocity dispersions for their stellar masses. The patterns likely reflect variations among star-forming environments and suggest that LGRBs can be used as probes of conditions in high-redshift galaxies. They may be caused by efficient formation of massive binary progenitor systems in densely star-forming regions, or, less probably, a higher fraction of stars created with the initial masses required for an SN Ic-BL or LGRB. Finally, we show that the preference of SNe Ic-BL and LGRBs for galaxies with high stellar mass and star formation rate densities cannot be attributed to a preference for low metal abundances but must reflect the influence of a separate environmental factor.

  5. Critical surface for explosions of rotational core-collapse supernovae

    SciTech Connect (OSTI)

    Iwakami, Wakana; Nagakura, Hiroki [Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto, 606-8502 (Japan); Yamada, Shoichi, E-mail: wakana@heap.phys.waseda.ac.jp [Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo, 169-8555 (Japan)

    2014-09-20

    The effect of rotation on the explosion of core-collapse supernovae is investigated systematically in three-dimensional simulations. In order to obtain the critical conditions for explosion as a function of mass accretion rate, neutrino luminosity, and specific angular momentum, rigidly rotating matter was injected from the outer boundary with an angular momentum, which is increased every 500 ms. It is found that there is a critical value of the specific angular momentum, above which the standing shock wave revives, for a given combination of mass accretion rate and neutrino luminosity, i.e., an explosion can occur by rotation even if the neutrino luminosity is lower than the critical value for a given mass accretion rate in non-rotational models. The coupling of rotation and hydrodynamical instabilities plays an important role in characterizing the dynamics of shock revival for the range of specific angular momentum that are supposed to be realistic. Contrary to expectations from past studies, the most rapidly expanding direction of the shock wave is not aligned with the rotation axis. Being perpendicular to the rotation axis on average, it can be oriented in various directions. Its dispersion is small when the spiral mode of the standing accretion shock instability (SASI) governs the dynamics, while it is large when neutrino-driven convection is dominant. As a result of the comparison between two-dimensional and three-dimensional rotational models, it is found that m ? 0 modes of neutrino-driven convection or SASI are important for shock revival around the critical surface.

  6. Interstellar and ejecta dust in the cas a supernova remnant

    SciTech Connect (OSTI)

    Arendt, Richard G.; Dwek, Eli; Kober, Gladys; Rho, Jeonghee; Hwang, Una

    2014-05-01

    Infrared continuum observations provide a means of investigating the physical composition of the dust in the ejecta and swept up medium of the Cas A supernova remnant (SNR). Using low-resolution Spitzer IRS spectra (5-35 ?m), and broad-band Herschel PACS imaging (70, 100, and 160 ?m), we identify characteristic dust spectra, associated with ejecta layers that underwent distinct nuclear burning histories. The most luminous spectrum exhibits strong emission features at ?9 and 21 ?m and is closely associated with ejecta knots with strong Ar emission lines. The dust features can be reproduced by magnesium silicate grains with relatively low Mg to Si ratios. Another dust spectrum is associated with ejecta having strong Ne emission lines. It has no indication of any silicate features and is best fit by Al{sub 2}O{sub 3} dust. A third characteristic dust spectrum shows features that are best matched by magnesium silicates with a relatively high Mg to Si ratio. This dust is primarily associated with the X-ray-emitting shocked ejecta, but it is also evident in regions where shocked interstellar or circumstellar material is expected. However, the identification of dust composition is not unique, and each spectrum includes an additional featureless dust component of unknown composition. Colder dust of indeterminate composition is associated with emission from the interior of the SNR, where the reverse shock has not yet swept up and heated the ejecta. Most of the dust mass in Cas A is associated with this unidentified cold component, which is ? 0.1 M {sub ?}. The mass of warmer dust is only ?0.04 M {sub ?}.

  7. LAX XXlCfl jX?iK, Idd+?KYLViG?IA

    Office of Legacy Management (LM)

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  8. Scattered-Light Echoes from the Historical Galactic Supernovae Cassiopeia A and Tycho (SN 1572)

    SciTech Connect (OSTI)

    Rest, A; Welch, D L; Suntzeff, N B; Oaster, L; Lanning, H; Olsen, K; Smith, R C; Becker, A C; Bergmann, M; Challis, P; Clocchiatti, A; Cook, K H; Damke, G; Garg, A; Huber, M E; Matheson, T; Minniti, D; Prieto, J L; Wood-Vasey, W M

    2008-05-06

    We report the discovery of an extensive system of scattered light echo arclets associated with the recent supernovae in the local neighborhood of the Milky Way: Tycho (SN 1572) and Cassiopeia A. Existing work suggests that the Tycho SN was a thermonuclear explosion while the Cas A supernova was a core collapse explosion. Precise classifications according to modern nomenclature require spectra of the outburst light. In the case of ancient SNe, this can only be done with spectroscopy of their light echo, where the discovery of the light echoes from the outburst light is the first step. Adjacent light echo positions suggest that Cas A and Tycho may share common scattering dust structures. If so, it is possible to measure precise distances between historical Galactic supernovae. On-going surveys that alert on the development of bright scattered-light echo features have the potential to reveal detailed spectroscopic information for many recent Galactic supernovae, both directly visible and obscured by dust in the Galactic plane.

  9. Spectrum and light curve of a supernova shock breakout through a thick Wolf-Rayet wind

    SciTech Connect (OSTI)

    Svirski, Gilad; Nakar, Ehud

    2014-06-20

    Wolf-Rayet stars are known to eject winds. Thus, when a Wolf-Rayet star explodes as a supernova, a fast (≳ 40, 000 km s{sup –1}) shock is expected to be driven through a wind. We study the signal expected from a fast supernova shock propagating through an optically thick wind and find that the electrons behind the shock driven into the wind are efficiently cooled by inverse Compton over soft photons that were deposited by the radiation-mediated shock that crossed the star. Therefore, the bolometric luminosity is comparable to the kinetic energy flux through the shock, and the spectrum is found to be a power law, whose slope and frequency range depend on the number flux of soft photons available for cooling. Wolf-Rayet supernovae that explode through a thick wind have a high flux of soft photons, producing a flat spectrum, νF {sub ν} = Const, in the X-ray range of 0.1 ≲ T ≲ 50 keV. As the shock expands into an optically thin wind, the soft photons are no longer able to cool the shock that plows through the wind, and the bulk of the emission takes the form of a standard core-collapse supernova (without a wind). However, a small fraction of the soft photons is upscattered by the shocked wind and produces a transient unique X-ray signature.

  10. Constraining absolute neutrino masses via detection of galactic supernova neutrinos at JUNO

    SciTech Connect (OSTI)

    Lu, Jia-Shu; Cao, Jun; Li, Yu-Feng; Zhou, Shun

    2015-05-26

    A high-statistics measurement of the neutrinos from a galactic core-collapse supernova is extremely important for understanding the explosion mechanism, and studying the intrinsic properties of neutrinos themselves. In this paper, we explore the possibility to constrain the absolute scale of neutrino masses m{sub ν} via the detection of galactic supernova neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO) with a 20 kiloton liquid-scintillator detector. In assumption of a nearly-degenerate neutrino mass spectrum and a normal mass ordering, the upper bound on the absolute neutrino mass is found to be m{sub ν}<(0.83±0.24) eV at the 95% confidence level for a typical galactic supernova at a distance of 10 kpc, where the mean value and standard deviation are shown to account for statistical fluctuations. For comparison, we find that the bound in the Super-Kamiokande experiment is m{sub ν}<(0.94±0.28) eV at the same confidence level. However, the upper bound will be relaxed when the model parameters characterizing the time structure of supernova neutrino fluxes are not exactly known, and when the neutrino mass ordering is inverted.

  11. FAINT POPULATION III SUPERNOVAE AS THE ORIGIN OF THE MOST IRON-POOR STARS

    SciTech Connect (OSTI)

    Ishigaki, Miho N.; Tominaga, Nozomu; Kobayashi, Chiaki; Nomoto, Ken'ichi, E-mail: miho.ishigaki@ipmu.jp [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan)

    2014-09-10

    The most iron-poor stars in the Milky Way provide important observational clues to the astrophysical objects that enriched the primordial gas with heavy elements. Among them, the recently discovered iron-deficient star SMSS J031300.36670839.3 shows a remarkable chemical composition with a non-detection of iron ([Fe/H] <7.1) and large enhancement of carbon and magnesium relative to calcium. We investigate supernova yields of metal-free (Population III) stars to interpret the abundance pattern observed in this star. We report that the high [C/Ca] and [C/Mg] ratios and upper limits of other elemental abundances are well reproduced with the yields of core-collapse supernovae (which have normal kinetic energies of explosion E of E {sub 51} = E/10{sup 51}erg=1) and hypernovae (E {sub 51} ? 10) of Population III 25 M {sub ?} or 40 M {sub ?} stars. The best-fit models assume that the explosions undergo extensive matter mixing and fallback, leaving behind a black hole remnant. In these models, Ca is produced by static/explosive O burning and incomplete Si burning in the Population III supernova/hypernova, in contrast to the suggestion that Ca is originated from the hot-CNO cycle during pre-supernova evolution. Chemical abundances of four carbon-rich iron-poor stars with [Fe/H] <4.5, including SMSS J031300.36670839.3, are consistently explained by faint supernova models with ejected masses of {sup 56}Ni less than 10{sup 3} M {sub ?}.

  12. Cosmic slowing down of acceleration for several dark energy parametrizations

    SciTech Connect (OSTI)

    Magaña, Juan; Cárdenas, Víctor H.; Motta, Verónica E-mail: victor.cardenas@uv.cl

    2014-10-01

    We further investigate slowing down of acceleration of the universe scenario for five parametrizations of the equation of state of dark energy using four sets of Type Ia supernovae data. In a maximal probability analysis we also use the baryon acoustic oscillation and cosmic microwave background observations. We found the low redshift transition of the deceleration parameter appears, independently of the parametrization, using supernovae data alone except for the Union 2.1 sample. This feature disappears once we combine the Type Ia supernovae data with high redshift data. We conclude that the rapid variation of the deceleration parameter is independent of the parametrization. We also found more evidence for a tension among the supernovae samples, as well as for the low and high redshift data.

  13. Computational Astrophysics Consortium 3 - Supernovae, Gamma-Ray...

    Office of Scientific and Technical Information (OSTI)

    Resource Type: Technical Report Research Org: The Regents of the University of California, Santa Cruz Sponsoring Org: USDOE NP, OASCR, NNSA, HEP Country of Publication: United ...

  14. XMM-NEWTON OBSERVATIONS OF TWO CANDIDATE SUPERNOVA REMNANTS

    SciTech Connect (OSTI)

    Kargaltsev, O.; Schmitt, B. M.; Pavlov, G. G.; Misanovic, Z.

    2012-01-20

    Candidate supernova remnants (SNRs) G23.5+0.1 and G25.5+0.0 were observed by XMM-Newton in the course of a snapshot survey of plerionic and composite SNRs in the Galactic plane. In the field of G23.5+0.1, we detected an extended source, {approx}3' in diameter, which we tentatively interpret as a pulsar wind nebula (PWN) of the middle-aged radio pulsar B1830-08 (J1833-0827; P = 85.3 ms, {tau} = 147 kyr, E-dot = 5.8 Multiplication-Sign 10{sup 35} erg s{sup -1}, d = 5.7 kpc), with the PWN luminosity L{sub 0.2-10keV} Almost-Equal-To 5 Multiplication-Sign 10{sup 33} erg s{sup -1} Almost-Equal-To 8 Multiplication-Sign 10{sup -3} E-dot . The pulsar is not resolved in the EPIC images. Our analysis suggests an association between PSR B1830-08 and the surrounding diffuse radio emission. If the radio emission is due to the SNR, then the pulsar must be significantly younger than its characteristic age. Alternatively, the radio emission may come from a relic PWN. The field also contains SGR 1833-0832 and another middle-aged pulsar B1829-08 (J1832-0827; P = 647 ms, {tau} = 161 kyr, E-dot = 9.3 Multiplication-Sign 10{sup 33} erg s{sup -1}, d = 4.7 kpc), none of which are detected in our observation. In the field of G25.5+0.0, which contains the extended TeV source HESS J1837-069, we detected the recently discovered young high-energy pulsar J1838-0655 (P = 70.5 ms, {tau} = 23 kyr, E-dot = 5.5 Multiplication-Sign 10{sup 36} erg s{sup -1}) embedded in a PWN with extent of 1.'3. The unabsorbed pulsar + PWN luminosity is L{sub 2-11keV} Almost-Equal-To 2 Multiplication-Sign 10{sup 34} erg s{sup -1} Almost-Equal-To 4 Multiplication-Sign 10{sup -3} E-dot at an assumed distance of 7 kpc. We also detected another PWN candidate (AX J1837.3-0652) with an extent of 2' and unabsorbed luminosity L{sub 2-10keV} Almost-Equal-To 4 Multiplication-Sign 10{sup 33} erg s{sup -1} at d = 7 kpc. The third X-ray source, located within the extent of the HESS J1837-069, has a peculiar extended radio

  15. Metabolomic profiling of the nectars of Aquilegia pubescens and <i>A. Canadensis

    SciTech Connect (OSTI)

    Noutsos, Christos; Perera, Ann M.; Nikolau, Basil J.; Seaver, Samuel M. D.; Ware, Doreen H.; Motta, Andrea

    2015-05-01

    To date, variation in nectar chemistry of flowering plants has not been studied in detail. Such variation exerts considerable influence on pollinator–plant interactions, as well as on flower traits that play important roles in the selection of a plant for visitation by specific pollinators. Over the past 60 years the Aquilegia genus has been used as a key model for speciation studies. In this study, we defined the metabolomic profiles of flower samples of two Aquilegia species, <i>A. Canadensis and <i>A. pubescens. We identified a total of 75 metabolites that were classified into six main categories: organic acids, fatty acids, amino acids, esters, sugars, and unknowns. The mean abundances of 25 of these metabolites were significantly different between the two species, providing insights into interspecies variation in floral chemistry. Using the PlantSEED biochemistry database, we found that the majority of these metabolites are involved in biosynthetic pathways. Finally, we explored the annotated genome of <i>A. coerulea, using the PlantSEED pipeline and reconstructed the metabolic network of Aquilegia. This network, which contains the metabolic pathways involved in generating the observed chemical variation, is now publicly available from the DOE Systems Biology Knowledge Base (KBase; http://kbase.us).

  16. LOW-RESOLUTION SPECTROSCOPY FOR THE GLOBULAR CLUSTERS WITH SIGNS OF SUPERNOVA ENRICHMENT: M22, NGC 1851, AND NGC 288

    SciTech Connect (OSTI)

    Lim, Dongwook; Han, Sang-Il; Lee, Young-Wook; Roh, Dong-Goo; Sohn, Young-Jong; Chun, Sang-Hyun; Lee, Jae-Woo; Johnson, Christian I.

    2015-01-01

    There is increasing evidence for the presence of multiple red giant branches (RGBs) in the color-magnitude diagrams of massive globular clusters (GCs). In order to investigate the origin of this split on the RGB, we have performed new narrow-band Ca photometry and low-resolution spectroscopy for M22, NGC 1851, and NGC 288. We find significant differences (more than 4σ) in calcium abundance from the spectroscopic HK' index for M22 and NGC 1851. We also find more than 8σ differences in CN-band strength between the Ca-strong and Ca-weak subpopulations for these GCs. For NGC 288, however, a large difference is detected only in the CN strength. The calcium abundances of RGB stars in this GC are identical to within the errors. This is consistent with the conclusion from our new Ca photometry where the RGB splits are confirmed in M22 and NGC 1851, but not in NGC 288. We also find interesting differences in the CN-CH correlations among these GCs. While CN and CH are anti-correlated in NGC 288, they show a positive correlation in M22. NGC 1851, however, shows no difference in CH between the two groups of stars with different CN strengths. We suggest that all of these systematic differences would be best explained by how strongly Type II supernovae enrichment has contributed to the chemical evolution of these GCs.

  17. RELATIVISTIC SUPERNOVAE HAVE SHORTER-LIVED CENTRAL ENGINES OR MORE EXTENDED PROGENITORS: THE CASE OF SN 2012ap

    SciTech Connect (OSTI)

    Margutti, R.; Milisavljevic, D.; Soderberg, A. M.; Sanders, N.; Chakraborti, S.; Kamble, A.; Drout, M.; Parrent, J.; Zauderer, A.; Guidorzi, C.; Morsony, B. J.; Ray, A.; Chomiuk, L.

    2014-12-20

    Deep, late-time X-ray observations of the relativistic, engine-driven, type Ic SN 2012ap allow us to probe the nearby environment of the explosion and reveal the unique properties of relativistic supernova explosions (SNe). We find that on a local scale of ∼0.01 pc the environment was shaped directly by the evolution of the progenitor star with a pre-explosion mass-loss rate of M-dot <5×10{sup −6} M{sub ⊙} yr{sup −1}, in line with gamma-ray bursts (GRBs) and the other relativistic SN 2009bb. Like sub-energetic GRBs, SN 2012ap is characterized by a bright radio emission and evidence for mildly relativistic ejecta. However, its late-time (δt ≈ 20 days) X-ray emission is ∼100 times fainter than the faintest sub-energetic GRB at the same epoch, with no evidence for late-time central engine activity. These results support theoretical proposals that link relativistic SNe like 2009bb and 2012ap with the weakest observed engine-driven explosions, where the jet barely fails to break out. Furthermore, our observations demonstrate that the difference between relativistic SNe and sub-energetic GRBs is intrinsic and not due to line-of-sight effects. This phenomenology can either be due to an intrinsically shorter-lived engine or to a more extended progenitor in relativistic SNe.

  18. Discovery of a pre-existing molecular filament associated with supernova remnant G127.1+0.5

    SciTech Connect (OSTI)

    Zhou, Xin; Yang, Ji; Fang, Min; Su, Yang

    2014-08-20

    We performed millimeter observations in CO lines toward the supernova remnant (SNR) G127.1+0.5. We found a molecular filament at 4-13 km s{sup –1} consisting of two distinct parts: a straight part coming out of the remnant region and a curved part in the remnant region. The curved part is coincides well with the bright SNR shell detected in 1420 MHz radio continuum and mid-infrared observations in the northeastern region. In addition, redshifted line wing broadening is found only in the curved part of the molecular filament, which indicates a physical interaction. These provide strong evidences, for the first time, to confirm the association between an SNR and a pre-existing long molecular filament. Multi-band observations in the northeastern remnant shell could be explained by the interaction between the remnant shock and the dense molecular filament. RADEX radiative transfer modeling of the quiet and shocked components yield physical conditions consistent with the passage of a non-dissociative J-type shock. We argue that the curved part of the filament is fully engulfed by the remnant's forward shock. A spatial correlation between aggregated young stellar objects (YSOs) and the adjacent molecular filament close to the SNR is also found, which could be related to the progenitor's activity.

  19. PRE-SUPERNOVA EVOLUTION OF ROTATING SOLAR METALLICITY STARS IN THE MASS RANGE 13-120 M {sub Sun} AND THEIR EXPLOSIVE YIELDS

    SciTech Connect (OSTI)

    Chieffi, Alessandro; Limongi, Marco E-mail: marco.limongi@oa-roma.inaf.it

    2013-02-10

    We present the first set of a new generation of models of massive stars with a solar composition extending between 13 and 120 M {sub Sun }, computed with and without the effects of rotation. We included two instabilities induced by rotation: the meridional circulation and the shear instability. We implemented two alternative schemes to treat the transport of the angular momentum: the advection-diffusion formalism and the simpler purely diffusive one. The full evolution from the pre-main sequence up to the pre-supernova stage is followed in detail with a very extended nuclear network. The explosive yields are provided for a variety of possible mass cuts and are available at the Web site http://www.iasf-roma.inaf.it/orfeo/public{sub h}tml. We find that both the He and the CO core masses are larger than those of their non-rotating counterparts. Also the C abundance left by the He burning is lower than in the non-rotating case, especially for stars with an initial mass of 13-25 M {sub Sun }, and this affects the final mass-radius relation, basically the final binding energy, at the pre-supernova stage. The elemental yields produced by a generation of stars rotating initially at 300 km s{sup -1} do not change substantially with respect to those produced by a generation of non-rotating massive stars, the main differences being a slight overproduction of the weak s-component and a larger production of F. Since rotation also affects the mass-loss rate, either directly or indirectly, we find substantial differences in the lifetimes as O-type and Wolf-Rayet subtypes between the rotating and non-rotating models. The maximum mass exploding as Type IIP supernova ranges between 15 and 20 M {sub Sun} in both sets of models (this value depends basically on the larger mass-loss rates in the red supergiant phase due to the inclusion of the dust-driven wind). This limiting value is in remarkably good agreement with current estimates.

  20. Optimal Extraction of Cosmological Information from Supernova Datain the Presence of Calibration Uncertainties

    SciTech Connect (OSTI)

    Kim, Alex G.; Miquel, Ramon

    2005-09-26

    We present a new technique to extract the cosmological information from high-redshift supernova data in the presence of calibration errors and extinction due to dust. While in the traditional technique the distance modulus of each supernova is determined separately, in our approach we determine all distance moduli at once, in a process that achieves a significant degree of self-calibration. The result is a much reduced sensitivity of the cosmological parameters to the calibration uncertainties. As an example, for a strawman mission similar to that outlined in the SNAP satellite proposal, the increased precision obtained with the new approach is roughly equivalent to a factor of five decrease in the calibration uncertainty.

  1. Supernova constraints on neutrino oscillation and EoS for proto-neutron star

    SciTech Connect (OSTI)

    Kajino, T.; Aoki, W.; Cheoun, M.-K.; Hayakawa, T.; Hidaka, J.; Hirai, Y.; Shibagaki, S.; Mathews, G. J.; Nakamura, K.; Suzuki, T.

    2014-05-02

    Core-collapse supernovae eject huge amount of flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We here discuss how to determine the neutrino temperatures and propose a method to determine still unknown neutrino oscillation parameters, mass hierarchy and ?{sub 13}, simultaneously. Combining the recent experimental constraints on ?{sub 13} with isotopic ratios of the light elements discovered in presolar grains from the Murchison meteorite, we show that our method suggests at a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

  2. Supernovae, Dark Energy and the Accelerating Universe: How DOE Helped to Win (yet another) Nobel Prize

    SciTech Connect (OSTI)

    Perlmutter, Saul

    2012-01-13

    The Department of Energy (DOE) hosted an event Friday, January 13, with 2011 Physics Nobel Laureate Saul Perlmutter. Dr. Perlmutter, a physicist at the Departments Lawrence Berkeley National Laboratory and a professor of physics at the University of California at Berkeley, won the 2011 Nobel Prize in Physics for the discovery of the accelerating expansion of the Universe through observations of distant supernovae. DOEs Office of Science has supported Dr. Perlmutters research at Berkeley Lab since 1983. After the introduction from Secretary of Energy Steven Chu, Dr. Perlmutter delivered a presentation entitled "Supernovae, Dark Energy and the Accelerating Universe: How DOE Helped to Win (yet another) Nobel Prize." [Copied with editing from DOE Media Advisory issued January 10th, found at http://energy.gov/articles/energy-department-host-event-2011-physics-nobel-laureate-saul-perlmutter

  3. Supernovae, Dark Energy and the Accelerating Universe: How DOE Helped to Win (yet another) Nobel Prize

    ScienceCinema (OSTI)

    Perlmutter, Saul

    2012-01-13

    The Department of Energy (DOE) hosted an event Friday, January 13, with 2011 Physics Nobel Laureate Saul Perlmutter. Dr. Perlmutter, a physicist at the Department?s Lawrence Berkeley National Laboratory and a professor of physics at the University of California at Berkeley, won the 2011 Nobel Prize in Physics ?for the discovery of the accelerating expansion of the Universe through observations of distant supernovae.? DOE?s Office of Science has supported Dr. Perlmutter?s research at Berkeley Lab since 1983. After the introduction from Secretary of Energy Steven Chu, Dr. Perlmutter delivered a presentation entitled "Supernovae, Dark Energy and the Accelerating Universe: How DOE Helped to Win (yet another) Nobel Prize." [Copied with editing from DOE Media Advisory issued January 10th, found at http://energy.gov/articles/energy-department-host-event-2011-physics-nobel-laureate-saul-perlmutter

  4. Multi-dimensional simulations of the expanding supernova remnant of SN 1987A

    SciTech Connect (OSTI)

    Potter, T. M.; Staveley-Smith, L. [International center for Radio Astronomy Research (ICRAR) M468, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia); Reville, B. [Center for Plasma Physics, Queen's University Belfast, University Road, Belfast BT7 1NN (United Kingdom); Ng, C.-Y. [Department of Physics, The University of Hong Kong, Pokfulam Road (Hong Kong); Bicknell, G. V.; Sutherland, R. S. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 0200 (Australia); Wagner, A. Y., E-mail: tobympotter@gmail.com [Center for Computational Sciences, Tsukuba University, Tsukuba, Ibaraki, 305-8577 (Japan)

    2014-10-20

    The expanding remnant from SN 1987A is an excellent laboratory for investigating the physics of supernovae explosions. There is still a large number of outstanding questions, such as the reason for the asymmetric radio morphology, the structure of the pre-supernova environment, and the efficiency of particle acceleration at the supernova shock. We explore these questions using three-dimensional simulations of the expanding remnant between days 820 and 10,000 after the supernova. We combine a hydrodynamical simulation with semi-analytic treatments of diffusive shock acceleration and magnetic field amplification to derive radio emission as part of an inverse problem. Simulations show that an asymmetric explosion, combined with magnetic field amplification at the expanding shock, is able to replicate the persistent one-sided radio morphology of the remnant. We use an asymmetric Truelove and McKee progenitor with an envelope mass of 10 M {sub ?} and an energy of 1.5 10{sup 44} J. A termination shock in the progenitor's stellar wind at a distance of 0.''43-0.''51 provides a good fit to the turn on of radio emission around day 1200. For the H II region, a minimum distance of 0.''63 0.''01 and maximum particle number density of (7.11 1.78) 10{sup 7} m{sup 3} produces a good fit to the evolving average radius and velocity of the expanding shocks from day 2000 to day 7000 after explosion. The model predicts a noticeable reduction, and possibly a temporary reversal, in the asymmetric radio morphology of the remnant after day 7000, when the forward shock left the eastern lobe of the equatorial ring.

  5. Research in nuclear astrophysics: Stellar collapse and supernovae. Performance reports, December 1, 1991--November 30, 1992

    SciTech Connect (OSTI)

    Lattimer, J.M.; Yahil, A.

    1992-07-01

    This progress report describes the nuclear astrophysics research activities in the Earth and Space Sciences Department at Stony Brook during the last year. Our research focused on three aspects of nuclear astrophysics: (1) the equation of state of hot, dense matter, (2) the origin of supernovae and neutron stars, (3) the early cooling epoch of neutron stars. The following contains detailed reports which summarize each completed project.

  6. Abundances of presolar graphite and SiC from supernovae and AGB stars in the Murchison meteorite

    SciTech Connect (OSTI)

    Amari, Sachiko; Zinner, Ernst; Gallino, Roberto

    2014-05-02

    Pesolar graphite grains exhibit a range of densities (1.65 – 2.20 g/cm{sup 3}). We investigated abundances of presolar graphite grains formed in supernovae and in asymptotic giant branch (AGB) stars in the four density fractions KE3, KFA1, KFB1 and KFC1 extracted from the Murchison meteorite to probe dust productions in these stellar sources. Seventy-six and 50% of the grains in the low-density fractions KE3 and KFA1, respectively, are supernova grains, while only 7.2% and 0.9% of the grains in the high-density fractions KFB1 and KFC1 have a supernova origin. Grains of AGB star origin are concentrated in the high-density fractions KFB1 and KFC1. From the C isotopic distributions of these fractions and the presence of s-process Kr with {sup 86}Kr/{sup 82}Kr = 4.43±0.46 in KFC1, we estimate that 76% and 80% of the grains in KFB1 and KFC1, respectively, formed in AGB stars. From the abundance of graphite grains in the Murchison meteorite, 0.88 ppm, the abundances of graphite from supernovae and AGB stars are 0.24 ppm and 0.44 ppm, respectively: the abundances of graphite in supernovae and AGB stars are comparable. In contrast, it has been known that 1% of SiC grains formed in supernovae and 95% formed in AGB stars in meteorites. Since the abundance of SiC grains is 5.85 ppm in the Murchison meteorite, the abundances of SiC from supernovae and AGB stars are 0.063 ppm and 5.6 ppm, respectively: the dominant source of SiC grains is AGB stars. Since SiC grains are harder and likely to survive better in space than graphite grains, the abundance of supernova graphite grains, which is higher than that of supernova SiC grains, indicates that supernovae proficiently produce graphite grains. Graphite grains from AGB stars are, in contrast, less abundant that SiC grains from AGB stars (0.44 ppm vs. 5.6 ppm). It is difficult to derive firm conclusions for graphite and SiC formation in AGB stars due to the difference in susceptibility to grain destruction. Metallicity of

  7. Finding the first cosmic explosions. IV. 90–140 $$\\;{{M}_{\\odot }}$$ pair-stability supernovae

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Smidt, Joseph; Whalen, Daniel J.; Chatzopoulos, E.; Wiggins, Brandon; Chen, Ke-Jung; Kozyreva, Alexandra; Even, Wesley

    2015-05-19

    Population III stars that die as pair-instability supernovae are usually thought to fall in the mass range of 140 - 260 M⊙. However, several lines of work have now shown that rotation can build up the He cores needed to encounter the pair instability at stellar masses as low as 90 M⊙. Depending on the slope of the initial mass function of Population III stars, there could be 4 - 5 times as many stars from 90 - 140 M⊙ in the primordial universe than in the usually accepted range. We present numerical simulations of the pair-instability explosions of suchmore » stars performed with the MESA, FLASH and RAGE codes. We find that they will be visible to supernova factories such as Pan-STARRS and LSST in the optical out to z ~ 1-2 and JWST and the 30 m-class telescopes in the NIR out to z ~ 7-10. Such explosions will thus probe the stellar populations of the first galaxies and cosmic star formation rates in the era of cosmological reionization. These supernovae are also easily distinguished from more massive pair-instability explosions, underscoring the fact that there is far greater variety to the light curves of these events than previously understood.« less

  8. Testing neutrino spectra formation in collapsing stars with the diffuse supernova neutrino flux

    SciTech Connect (OSTI)

    Lunardini, Cecilia

    2007-04-01

    I address the question of what can be learned from the observation of the diffuse supernova neutrino flux in the precision phase, at next generation detectors of Megaton scale. An analytical study of the spectrum of the diffuse flux shows that, above realistic detection thresholds of 10 MeV or higher, the spectrum essentially reflects the exponential-times-polynomial structure of the original neutrino spectrum at the emission point. There is only a weak (tens of percent) dependence on the power {beta} describing the growth of the supernova rate with the redshift. Different original neutrino spectra correspond to large differences in the observed spectrum of events at a water Cherenkov detector: for typical supernova rates, the ratio of the numbers of events in the first and second energy bins (of 5 MeV width) varies in the interval 1.5-4.3 for pure water (energy threshold 18 MeV) and in the range 1-2.5 for water with gadolinium (10 MeV threshold). In the first case, discrimination would be difficult due to the large errors associated with background. With gadolinium, instead, the reduction of the total error down to the 10%-20% level would allow spectral sensitivity, with a dramatic improvement of precision with respect to the SN1987A data. Even in this latter case, for typical neutrino luminosity the dependence on {beta} is below sensitivity, so that it can be safely neglected in data analysis.

  9. Finding the first cosmic explosions. IV. 90–140 $\\;{{M}_{\\odot }}$ pair-stability supernovae

    SciTech Connect (OSTI)

    Smidt, Joseph; Whalen, Daniel J.; Chatzopoulos, E.; Wiggins, Brandon; Chen, Ke-Jung; Kozyreva, Alexandra; Even, Wesley

    2015-05-19

    Population III stars that die as pair-instability supernovae are usually thought to fall in the mass range of 140 - 260 M. However, several lines of work have now shown that rotation can build up the He cores needed to encounter the pair instability at stellar masses as low as 90 M. Depending on the slope of the initial mass function of Population III stars, there could be 4 - 5 times as many stars from 90 - 140 M in the primordial universe than in the usually accepted range. We present numerical simulations of the pair-instability explosions of such stars performed with the MESA, FLASH and RAGE codes. We find that they will be visible to supernova factories such as Pan-STARRS and LSST in the optical out to z ~ 1-2 and JWST and the 30 m-class telescopes in the NIR out to z ~ 7-10. Such explosions will thus probe the stellar populations of the first galaxies and cosmic star formation rates in the era of cosmological reionization. These supernovae are also easily distinguished from more massive pair-instability explosions, underscoring the fact that there is far greater variety to the light curves of these events than previously understood.

  10. Weak decay processes in pre-supernova core evolution within the gross theory

    SciTech Connect (OSTI)

    Ferreira, R. C.; Dimarco, A. J.; Samana, A. R.; Barbero, C. A.

    2014-03-20

    The beta decay and electron capture rates are of fundamental importance in the evolution of massive stars in a pre-supernova core. The beta decay process gives its contribution by emitting electrons in the plasma of the stellar core, thereby increasing pressure, which in turn increases the temperature. From the other side, the electron capture removes free electrons from the plasma of the star core contributing to the reduction of pressure and temperature. In this work we calculate the beta decay and electron capture rates in stellar conditions for 63 nuclei of relevance in the pre-supernova stage, employing Gross Theory as the nuclear model. We use the abundances calculated with the Saha equations in the hypothesis of nuclear statistical equilibrium to evaluate the time derivative of the fraction of electrons. Our results are compared with other evaluations available in the literature. They have shown to be one order less or equal than the calculated within other models. Our results indicate that these differences may influence the evolution of the star in the later stages of pre-supernova.

  11. Blue supergiant model for ultra-long gamma-ray burst with superluminous-supernova-like bump

    SciTech Connect (OSTI)

    Nakauchi, Daisuke; Nakamura, Takashi; Kashiyama, Kazumi; Suwa, Yudai

    2013-11-20

    Long gamma-ray bursts (LGRBs) have a typical duration of ∼30 s, and some of them are associated with hypernovae, such as Type Ic SN 1998bw. Wolf-Rayet stars are the most plausible LGRB progenitors, since the free fall time of the envelope is consistent with the duration, and the natural outcome of the progenitor is a Type Ic SN. While a new population of ultra-long GRBs (ULGRBs), GRB 111209A, GRB 101225A, and GRB 121027A, has a duration of ∼10{sup 4} s, two of them are accompanied by superluminous-supernova-like (SLSN-like) bumps, which are ≲ 10 times brighter than typical hypernovae. Wolf-Rayet progenitors cannot explain ULGRBs because of durations that are too long and SN-like bumps that are too bright. A blue supergiant (BSG) progenitor model, however, can explain the duration of ULGRBs. Moreover, SLSN-like bumps can be attributed to the so-called cocoon fireball photospheric emissions (CFPEs). Since a large cocoon is inevitably produced during the relativistic jet piercing though the BSG envelope, this component can be smoking gun evidence of the BSG model for ULGRBs. In this paper, we examine u-, g-, r-, i-, and J-band light curves of three ULGRBs and demonstrate that they can be fitted quite well by our BSG model with the appropriate choices of the jet opening angle and the number density of the ambient gas. In addition, we predict that for 121027A, SLSN-like bump could have been observed for ∼20-80 days after the burst. We also propose that some SLSNe might be CFPEs of off-axis ULGRBs without visible prompt emissions.

  12. A review of direct numerical simulations of astrophysical detonations and their implications

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Parete-Koon, Suzanne T.; Smith, Christopher R.; Papatheodore, Thomas L.; Bronson Messer, O. E.

    2013-04-11

    Multi-dimensional direct numerical simulations (DNS) of astrophysical detonations in degenerate matter have revealed that the nuclear burning is typically characterized by cellular structure caused by transverse instabilities in the detonation front. Type Ia supernova modelers often use one- dimensional DNS of detonations as inputs or constraints for their whole star simulations. While these one-dimensional studies are useful tools, the true nature of the detonation is multi-dimensional. The multi-dimensional structure of the burning influences the speed, stability, and the composition of the detonation and its burning products, and therefore, could have an impact on the spectra of Type Ia supernovae. Considerablemore » effort has been expended modeling Type Ia supernovae at densities above 1x107 g∙cm-3 where the complexities of turbulent burning dominate the flame propagation. However, most full star models turn the nuclear burning schemes off when the density falls below 1x107 g∙cm-3 and distributed burning begins. The deflagration to detonation transition (DDT) is believed to occur at just these densities and consequently they are the densities important for studying the properties of the subsequent detonation. In conclusion, this work reviews the status of DNS studies of detonations and their possible implications for Type Ia supernova models. It will cover the development of Detonation theory from the first simple Chapman-Jouguet (CJ) detonation models to the current models based on the time-dependent, compressible, reactive flow Euler equations of fluid dynamics.« less

  13. Award Types

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Awards Team (505) 667-7824 Email Types of Awards The Awards Office, sponsored by the Technology Transfer Division and the Science and Technology Base Program Office, coordinates...

  14. MULTI-DIMENSIONAL FEATURES OF NEUTRINO TRANSFER IN CORE-COLLAPSE SUPERNOVAE

    SciTech Connect (OSTI)

    Sumiyoshi, K. [Numazu College of Technology, Ooka 3600, Numazu, Shizuoka 410-8501 (Japan); Takiwaki, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Matsufuru, H. [Computing Research Center, High Energy Accelerator Research Organization 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Yamada, S., E-mail: sumi@numazu-ct.ac.jp, E-mail: takiwaki.tomoya@nao.ac.jp, E-mail: hideo.matsufuru@kek.jp, E-mail: shoichi@heap.phys.waseda.ac.jp [Science and Engineering and Advanced Research Institute for Science and Engineering, Waseda University, Okubo, 3-4-1, Shinjuku, Tokyo 169-8555 (Japan)

    2015-01-01

    We study the multi-dimensional properties of neutrino transfer inside supernova cores by solving the Boltzmann equations for neutrino distribution functions in genuinely six-dimensional phase space. Adopting representative snapshots of the post-bounce core from other supernova simulations in three dimensions, we solve the temporal evolution to stationary states of neutrino distribution functions using our Boltzmann solver. Taking advantage of the multi-angle and multi-energy feature realized by the S {sub n} method in our code, we reveal the genuine characteristics of spatially three-dimensional neutrino transfer, such as nonradial fluxes and nondiagonal Eddington tensors. In addition, we assess the ray-by-ray approximation, turning off the lateral-transport terms in our code. We demonstrate that the ray-by-ray approximation tends to propagate fluctuations in thermodynamical states around the neutrino sphere along each radial ray and overestimate the variations between the neutrino distributions on different radial rays. We find that the difference in the densities and fluxes of neutrinos between the ray-by-ray approximation and the full Boltzmann transport becomes ?20%, which is also the case for the local heating rate, whereas the volume-integrated heating rate in the Boltzmann transport is found to be only slightly larger (?2%) than the counterpart in the ray-by-ray approximation due to cancellation among different rays. These results suggest that we should carefully assess the possible influences of various approximations in the neutrino transfer employed in current simulations of supernova dynamics. Detailed information on the angle and energy moments of neutrino distribution functions will be profitable for the future development of numerical methods in neutrino-radiation hydrodynamics.

  15. INJECTION AND ACCELERATION OF ELECTRONS AT A STRONG SHOCK: RADIO AND X-RAY STUDY OF YOUNG SUPERNOVA 2011dh

    SciTech Connect (OSTI)

    Maeda, Keiichi

    2012-10-20

    In this paper, we develop a model for the radio and X-ray emissions from the Type IIb supernova (SN IIb) 2011dh in the first 100 days after the explosion, and investigate a spectrum of relativistic electrons accelerated at a strong shock wave. The widely accepted theory of particle acceleration, the so-called diffusive shock acceleration (DSA) or Fermi mechanism, requires seed electrons with modest energy with {gamma} {approx} 1-100, and little is known about this pre-acceleration mechanism. We derive the energy distribution of relativistic electrons in this pre-accelerated energy regime. We find that the efficiency of the electron acceleration must be low, i.e., {epsilon}{sub e} {approx}< 10{sup -2} as compared to the conventionally assumed value of {epsilon}{sub e} {approx} 0.1. Furthermore, independent of the low value of {epsilon}{sub e}, we find that the X-ray luminosity cannot be attributed to any emission mechanisms suggested as long as these electrons follow the conventionally assumed single power-law distribution. A consistent view between the radio and X-ray can only be obtained if the pre-acceleration injection spectrum peaks at {gamma} {approx} 20-30 and then only a fraction of these electrons eventually experience the DSA-like acceleration toward the higher energy-then the radio and X-ray properties are explained through the synchrotron and inverse Compton mechanisms, respectively. Our findings support the idea that the pre-acceleration of the electrons is coupled with the generation/amplification of the magnetic field.

  16. MULTI-COLOR OPTICAL AND NEAR-INFRARED LIGHT CURVES OF 64 STRIPPED-ENVELOPE CORE-COLLAPSE SUPERNOVAE

    SciTech Connect (OSTI)

    Bianco, F. B.; Modjaz, M. [Center for Cosmology and Particle Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Hicken, M.; Friedman, A.; Kirshner, R. P.; Challis, P.; Marion, G. H. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bloom, J. S. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Wood-Vasey, W. M. [PITT PACC, Department of Physics and Astronomy, 3941 O'Hara Street, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Rest, A., E-mail: fb55@nyu.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2014-08-01

    We present a densely sampled, homogeneous set of light curves of 64 low-redshift (z ? 0.05) stripped-envelope supernovae (SNe of Type IIb, Ib, Ic, and Ic-BL). These data were obtained between 2001 and 2009 at the Fred L. Whipple Observatory (FLWO) on Mount Hopkins in Arizona, with the optical FLWO 1.2 m and the near-infrared (NIR) Peters Automated Infrared 1.3 m telescopes. Our data set consists of 4543 optical photometric measurements on 61 SNe, including a combination of U BV RI, U BV r{sup ?}i{sup ?}, and u{sup ?} BV r{sup ?}i{sup ?}, and 1919 JHK{sub s} NIR measurements on 25 SNe. This sample constitutes the most extensive multi-color data set of stripped-envelope SNe to date. Our photometry is based on template-subtracted images to eliminate any potential host-galaxy light contamination. This work presents these photometric data, compares them with data in the literature, and estimates basic statistical quantities: date of maximum, color, and photometric properties. We identify promising color trends that may permit the identification of stripped-envelope SN subtypes from their photometry alone. Many of these SNe were observed spectroscopically by the Harvard-Smithsonian Center for Astrophysics (CfA) SN group, and the spectra are presented in a companion paper. A thorough exploration that combines the CfA photometry and spectroscopy of stripped-envelope core-collapse SNe will be presented in a follow-up paper.

  17. Interaction-powered supernovae: rise-time versus peak-luminosity correlation and the shock-breakout velocity

    SciTech Connect (OSTI)

    Ofek, Eran O.; Arcavi, Iair; Tal, David; Gal-Yam, Avishay; Ben-Ami, Sagi; De Cia, Annalisa; Yaron, Ofer; Sullivan, Mark; Kulkarni, Shrinivas R.; Cao, Yi; Nugent, Peter E.; Bersier, David; Cenko, S. Bradley; Filippenko, Alexei V.; Fransson, Claes; Kasliwal, Mansi M.; Laher, Russ; Surace, Jason; Quimby, Robert

    2014-06-20

    Interaction of supernova (SN) ejecta with the optically thick circumstellar medium (CSM) of a progenitor star can result in a bright, long-lived shock-breakout event. Candidates for such SNe include Type IIn and superluminous SNe. If some of these SNe are powered by interaction, then there should be a specific relation between their peak luminosity, bolometric light-curve rise time, and shock-breakout velocity. Given that the shock velocity during shock breakout is not measured, we expect a correlation, with a significant spread, between the rise time and the peak luminosity of these SNe. Here, we present a sample of 15 SNe IIn for which we have good constraints on their rise time and peak luminosity from observations obtained using the Palomar Transient Factory. We report on a possible correlation between the R-band rise time and peak luminosity of these SNe, with a false-alarm probability of 3%. Assuming that these SNe are powered by interaction, combining these observables and theory allows us to deduce lower limits on the shock-breakout velocity. The lower limits on the shock velocity we find are consistent with what is expected for SNe (i.e., ∼10{sup 4} km s{sup –1}). This supports the suggestion that the early-time light curves of SNe IIn are caused by shock breakout in a dense CSM. We note that such a correlation can arise from other physical mechanisms. Performing such a test on other classes of SNe (e.g., superluminous SNe) can be used to rule out the interaction model for a class of events.

  18. SUPERNOVA SHOCK-WAVE-INDUCED CO-FORMATION OF GLASSY CARBON AND NANODIAMOND

    SciTech Connect (OSTI)

    Stroud, Rhonda; Chisholm, Matthew F; Heck, Phillipp; Alexander, Conel; Nittler, Larry

    2011-01-01

    Nanodiamond (ND) was the first extrasolar dust phase to be identified in meteorites. However, the 2 nm average size of the NDs precludes isotopic analysis of individual particles, and thus their origin(s) remains controversial. Using electron microscopy with subnanometer resolution, we show that ND separates from the Allende and Murchison meteorites are actually a two-phase mixture of ND and glassy carbon. This phase mixture is likely the product of supernova shock-wave transformation of pre-formed organics in the interstellar medium (ISM). The glassy carbon ND mixture is also a plausible contributor to the 2175 extinction feature in the diffuse ISM.

  19. OSTIblog Articles in the supernovae Topic | OSTI, US Dept of Energy Office

    Office of Scientific and Technical Information (OSTI)

    of Scientific and Technical Information supernovae Topic Observing Gamma-ray Bursts in Distant Galaxies by Kathy Chambers 21 Nov, 2013 in Science Communications 13926 Gamma-ray%20burst_caption.jpg Observing Gamma-ray Bursts in Distant Galaxies Read more about 13926 Star gazing seems especially good on a clear autumn night. From our back deck our amateur eyes scan the sky and its wonder. We first notice Venus, our closest planetary neighbor. A beautiful harvest moon rises over the hill,

  20. HYDRODYNAMICS OF CORE-COLLAPSE SUPERNOVAE AT THE TRANSITION TO EXPLOSION. I. SPHERICAL SYMMETRY

    SciTech Connect (OSTI)

    Fernandez, Rodrigo [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)

    2012-04-20

    We study the transition to runaway expansion of an initially stalled core-collapse supernova shock. The neutrino luminosity, mass accretion rate, and neutrinospheric radius are all treated as free parameters. In spherical symmetry, this transition is mediated by a global non-adiabatic instability that develops on the advection time and reaches nonlinear amplitude. Here, we perform high-resolution, time-dependent hydrodynamic simulations of stalled supernova shocks with realistic microphysics to analyze this transition. We find that radial instability is a sufficient condition for runaway expansion if the neutrinospheric parameters do not vary with time and if heating by the accretion luminosity is neglected. For a given unstable mode, transition to runaway occurs when fluid in the gain region reaches positive specific energy. We find approximate instability criteria that accurately describe the behavior of the system over a wide region of parameter space. The threshold neutrino luminosities are in general different than the limiting value for a steady-state solution. We hypothesize that multidimensional explosions arise from the excitation of unstable large-scale modes of the turbulent background flow, at threshold luminosities that are lower than in the laminar case.

  1. A THEORETICAL COLOR-VELOCITY CORRELATION FOR SUPERNOVAE ASSOCIATED WITH GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Rapoport, Sharon; Sim, Stuart A.; Schmidt, Brian P.; Maeda, Keiichi; Nomoto, Ken'ichi; Tanaka, Masaomi; Kromer, Markus

    2012-11-01

    We carry out the first multi-dimensional radiative transfer calculations to simultaneously compute synthetic spectra and light curves for models of supernovae driven by fast bipolar outflows. These allow us to make self-consistent predictions for the orientation dependence of both color evolution and spectral features. We compare models with different degrees of asphericity and metallicity and find significant observable consequences of both. In aspherical models, we find spectral and light curve features that vary systematically with observer orientation. In particular, we find that the early-phase light curves are brighter and bluer when viewed close to the polar axis but that the peak flux is highest for equatorial (off-axis) inclinations. Spectral line features also depend systematically on observer orientation, including the velocity of the Si II 6355 A line. Consequently, our models predict a correlation between line velocity and color that could assist the identification of supernovae associated with off-axis jet-driven explosions. The amplitude and range of this correlation depends on the degree of asphericity, the metallicity, and the epoch of observation but we find that it is always present and acts in the same direction.

  2. Collective flavor oscillations of supernova neutrinos and r-process nucleosynthesis

    SciTech Connect (OSTI)

    Chakraborty, Sovan; Kar, Kamales; Goswami, Srubabati E-mail: sandhya@hri.res.in E-mail: kamales.kar@saha.ac.in

    2010-06-01

    Neutrino-neutrino interactions inside core-collapse supernovae may give rise to collective flavor oscillations resulting in swap between flavors. These oscillations depend on the initial energy spectra, and relative fluxes or relative luminosities of the neutrinos. It has been observed that departure from energy equipartition among different flavors can give rise to one or more sharp spectral swap over energy, termed as splits. We study the occurrence of splits in the neutrino and antineutrino spectra, varying the initial relative fluxes for different models of initial energy spectrum, in both normal and inverted hierarchy. These initial relative flux variations give rise to several possible split patterns whereas variation over different models of energy spectra give similar results. We explore the effect of these spectral splits on the electron fraction, Y{sub e}, that governs r-process nucleosynthesis inside supernovae. Since spectral splits modify the electron neutrino and antineutrino spectra in the region where r-process is postulated to happen, and since the pattern of spectral splits depends on the initial conditions of the spectra and the neutrino mass hierarchy, we show that the condition Y{sub e} < 0.5 required for successful r-process nucleosynthesis will lead to constraints on the initial spectral conditions, for a given neutrino mass hierarchy.

  3. THE MORPHOLOGY AND DYNAMICS OF JET-DRIVEN SUPERNOVA REMNANTS: THE CASE OF W49B

    SciTech Connect (OSTI)

    González-Casanova, Diego F.; De Colle, Fabio; Ramirez-Ruiz, Enrico; Lopez, Laura A.

    2014-02-01

    The circumstellar medium (CSM) of a massive star is modified by its winds before a supernova (SN) explosion occurs, and thus the evolution of the resulting supernova remnant (SNR) is influenced by both the geometry of the explosion as well as the complex structure of the CSM. Motivated by recent work suggesting the SNR W49B was a jet-driven SN expanding in a complex CSM, we explore how the dynamics and the metal distributions in a jet-driven explosion are modified by the interaction with the surrounding environment. In particular, we perform hydrodynamical calculations to study the dynamics and explosive nucleosynthesis of a jet-driven SN triggered by the collapse of a 25 M {sub ☉} Wolf-Rayet star and its subsequent interaction with the CSM up to several hundred years following the explosion. We find that although the CSM has small-scale effects on the structure of the SNR, the overall morphology and abundance patterns are reflective of the initial asymmetry of the SN explosion. Thus, we predict that jet-driven SNRs, such as W49B, should be identifiable based on morphology and abundance patterns at ages up to several hundred years, even if they expand into a complex CSM environment.

  4. Shell effects in hot nuclei and their influence on nuclear composition in supernova matter

    SciTech Connect (OSTI)

    Nishimura, Suguru [Department of Pure and Applied Physics, Waseda University, 3-4-1 Okubo Shinjuku-ku, Tokyo 169-8555 (Japan); Takano, Masatoshi [Department of Pure and Applied Physics, Waseda University, 3-4-1 Okubo Shinjuku-ku, Tokyo 169-8555, Japan and Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo Shinjuku-ku, Tokyo 169-8555 (Japan)

    2014-05-02

    We calculate nuclear composition in supernova (SN) matter explicitly taking into account the temperature dependence of nuclear shell effects. The abundance of nuclei in SN matter is important in the dynamics of core-collapse supernovae and, in recently constructed equations of state (EOS) for SN matter, the composition of nuclei are calculated assuming nuclear statistical equilibrium wherein the nuclear internal free energies govern the composition. However, in these EOS, thermal effects on the shell energy are not explicitly taken into account. To address this shortfall, we calculate herein the shell energies of hot nuclei and examine their influence on the composition of SN matter. Following a simplified macroscopic-microscopic approach, we first calculate single-particle (SP) energies by using a spherical Woods-Saxon potential. Then we extract shell energies at finite temperatures using Strutinsky method with the Fermi distribution as the average occupation probability of the SP levels. The results show that at relatively low temperatures, shell effects are still important and magic nuclei are abundant. However, at temperatures above approximately 2 MeV, shell effects are almost negligible, and the mass fractions with shell energies including the thermal effect are close to those obtained from a simple liquid drop model at finite temperatures.

  5. Type: Renewal

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    1 INCITE Awards Type: Renewal Title: -Ab Initio Dynamical Simulations for the Prediction of Bulk Properties‖ Principal Investigator: Theresa Windus, Iowa State University Co-Investigators: Brett Bode, Iowa State University Graham Fletcher, Argonne National Laboratory Mark Gordon, Iowa State University Monica Lamm, Iowa State University Michael Schmidt, Iowa State University Scientific Discipline: Chemistry: Physical INCITE Allocation: 10,000,000 processor hours Site: Argonne National

  6. Facility Type!

    Office of Legacy Management (LM)

    ITY: --&L~ ----------- srct-r~ -----------~------~------- if yee, date contacted ------------- cl Facility Type! i I 0 Theoretical Studies Cl Sample 84 Analysis ] Production 1 Diepasal/Storage 'YPE OF CONTRACT .--------------- 1 Prime J Subcontract&- 1 Purchase Order rl i '1 ! Other information (i.e., ---------~---~--~-------- :ontrait/Pirchaee Order # , I C -qXlJ- --~-------~~-------~~~~~~ I I ~~~---~~~~~~~T~~~ FONTRACTING PERIODi IWNERSHIP: ,I 1 AECIMED AECMED GOVT GOUT &NTtiAC+OR

  7. Tabulated equation of state for supernova matter including full nuclear ensemble

    SciTech Connect (OSTI)

    Buyukcizmeci, N.; Botvina, A. S.; Mishustin, I. N. [Frankfurt Institute for Advanced Studies, J.W. Goethe University, D-60438 Frankfurt am Main (Germany)

    2014-07-01

    This is an introduction to the tabulated database of stellar matter properties calculated within the framework of the Statistical Model for Supernova Matter (SMSM). The tables present thermodynamical characteristics and nuclear abundances for 31 values of baryon density (10{sup 8} < ?/?{sub 0} < 0.32, ?{sub 0} = 0.15 fm{sup 3} is the normal nuclear matter density), 35 values of temperature (0.2 MeV < T < 25 MeV), and 28 values of electron-to-baryon ratio (0.02 < Y{sub e} < 0.56). The properties of stellar matter in ? equilibrium are also considered. The main ingredients of the SMSM are briefly outlined, and the data structure and content of the tables are explained.

  8. Detection of class I methanol (CH{sub 3}OH) maser candidates in supernova remnants

    SciTech Connect (OSTI)

    Pihlstrm, Y. M.; Mesler, R. A.; McEwen, B. C.; Sjouwerman, L. O.; Frail, D. A.; Claussen, M. J.

    2014-04-01

    We have used the Karl G. Jansky Very Large Array to search for 36 GHz and 44 GHz methanol (CH{sub 3}OH) lines in a sample of 21 Galactic supernova remnants (SNRs). Mainly the regions of the SNRs with 1720 MHz OH masers were observed. Despite the limited spatial extent covered in our search, methanol masers were detected in both G1.40.1 and W28. Additional masers were found in Sgr A East. More than 40 masers were found in G1.40.1, which we deduce are due to interactions between the SNR and at least two separate molecular clouds. The six masers in W28 are associated with the molecular cloud that is also associated with the OH maser excitation. We discuss the possibility that the methanol maser may be more numerous in SNRs than the OH maser, but harder to detect due to observational constraints.

  9. The diffuse source at the center of LMC SNR 050967.5 is a background galaxy at z = 0.031

    SciTech Connect (OSTI)

    Pagnotta, Ashley [Department of Astrophysics, American Museum of Natural History, New York, NY 10024 (United States); Walker, Emma S. [Department of Physics, Yale University, New Haven, CT 06520 (United States); Schaefer, Bradley E., E-mail: pagnotta@amnh.org [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States)

    2014-06-20

    Type Ia supernovae (SNe Ia) are well-known for their use in the measurement of cosmological distances, but our continuing lack of concrete knowledge about their progenitor stars is both a matter of debate and a source of systematic error. In our attempts to answer this question, we presented unambiguous evidence that LMC SNR 050967.5, the remnant of an SN Ia that exploded in the Large Magellanic Cloud 400 50 yr ago, did not have any point sources (stars) near the site of the original supernova explosion, from which we concluded that this particular supernova must have had a progenitor system consisting of two white dwarfs. There is, however, evidence of nebulosity near the center of the remnant, which could have been left over detritus from the less massive WD, or could have been a background galaxy unrelated to the supernova explosion. We obtained long-slit spectra of the central nebulous region using GMOS on Gemini South to determine which of these two possibilities is correct. The spectra show H? emission at a redshift of z = 0.031, which implies that the nebulosity in the center of LMC SNR 050967.5 is a background galaxy, unrelated to the supernova.

  10. Type here

    Office of Environmental Management (EM)

    Injury at the Savannah River National Laboratory | Department of Energy January 10, 2006, Flash Fire and Injury at the Savannah River National Laboratory Type B Accident Investigation of the January 10, 2006, Flash Fire and Injury at the Savannah River National Laboratory February 1, 2006 On January 10, 2006, at approximately 7:47 a.m., a first-line manager (FLM) at the Savannah River National Laboratory (SRNL) received first- and second-degree burns to his head, face, neck, and left hand

  11. THE IMPORTANCE OF PHYSICAL MODELS FOR DERIVING DUST MASSES AND GRAIN SIZE DISTRIBUTIONS IN SUPERNOVA EJECTA. I. RADIATIVELY HEATED DUST IN THE CRAB NEBULA

    SciTech Connect (OSTI)

    Temim, Tea; Dwek, Eli, E-mail: tea.temim@nasa.gov [Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2013-09-01

    Recent far-infrared (IR) observations of supernova remnants (SNRs) have revealed significantly large amounts of newly condensed dust in their ejecta, comparable to the total mass of available refractory elements. The dust masses derived from these observations assume that all the grains of a given species radiate at the same temperature, regardless of the dust heating mechanism or grain radius. In this paper, we derive the dust mass in the ejecta of the Crab Nebula, using a physical model for the heating and radiation from the dust. We adopt a power-law distribution of grain sizes and two different dust compositions (silicates and amorphous carbon), and calculate the heating rate of each dust grain by the radiation from the pulsar wind nebula. We find that the grains attain a continuous range of temperatures, depending on their size and composition. The total mass derived from the best-fit models to the observed IR spectrum is 0.019-0.13 M{sub Sun }, depending on the assumed grain composition. We find that the power-law size distribution of dust grains is characterized by a power-law index of 3.5-4.0 and a maximum grain size larger than 0.1 {mu}m. The grain sizes and composition are consistent with what is expected for dust grains formed in a Type IIP supernova (SN). Our derived dust mass is at least a factor of two less than the mass reported in previous studies of the Crab Nebula that assumed more simplified two-temperature models. These models also require a larger mass of refractory elements to be locked up in dust than was likely available in the ejecta. The results of this study show that a physical model resulting in a realistic distribution of dust temperatures can constrain the dust properties and affect the derived dust masses. Our study may also have important implications for deriving grain properties and mass estimates in other SNRs and for the ultimate question of whether SNe are major sources of dust in the Galactic interstellar medium and in

  12. A DETAILED STUDY OF NON-THERMAL X-RAY PROPERTIES AND INTERSTELLAR GAS TOWARD THE γ-RAY SUPERNOVA REMNANT RX J1713.7–3946

    SciTech Connect (OSTI)

    Sano, H.; Fukuda, T.; Yoshiike, S.; Sato, J.; Horachi, H.; Kuwahara, T.; Torii, K.; Hayakawa, T.; Matsumoto, H.; Inutsuka, S.; Yamamoto, H.; Tachihara, K.; Tanaka, T.; Inoue, T.; Kawamura, A.; Okuda, T.; Mizuno, N.; Yamazaki, R.; Onishi, T.; Mizuno, A.; and others

    2015-02-01

    We have carried out a spectral analysis of the Suzaku X-ray data in the 0.4-12 keV range toward the shell-type very high-energy γ-ray supernova remnant (SNR) RX J1713.7–3946. The aims of this analysis are to estimate detailed X-rays spectral properties at a high angular resolution up to 2 arcmin and to compare them with the interstellar gas. The X-ray spectrum is non-thermal and used to calculate absorbing column density, photon index, and absorption-corrected X-ray flux. The photon index varies significantly from 2.1 to 2.9. It is shown that the X-ray intensity is well correlated with the photon index, especially in the west region, with a correlation coefficient of 0.81. The X-ray intensity tends to increase with the averaged interstellar gas density while the dispersion is relatively large. The hardest spectra, with photon indexes of less than 2.4, are found outside of the central 10 arcmin of the SNR, from the north to the southeast (∼430 arcmin{sup 2}) and from the southwest to the northwest (∼150 arcmin{sup 2}). The former region shows low interstellar gas density, while the latter shows high interstellar gas density. We present a discussion of possible scenarios that explain the distribution of the photon index and its relationship with the interstellar gas.

  13. INFLUENCE OF MAGNETOROTATIONAL INSTABILITY ON NEUTRINO HEATING: A NEW MECHANISM FOR WEAKLY MAGNETIZED CORE-COLLAPSE SUPERNOVAE

    SciTech Connect (OSTI)

    Sawai, Hidetomo; Yamada, Shoichi

    2014-03-20

    We investigated the impact of magnetorotational instability (MRI) on the dynamics of weakly magnetized, rapidly rotating core-collapse supernovae by conducting high-resolution axisymmetric MHD simulations with simplified neutrino transfer. We found that an initially sub-magnetar-class magnetic field is drastically amplified by MRI and substantially affects the dynamics thereafter. Although the magnetic pressure is not strong enough to eject matter, the amplified magnetic field efficiently transfers angular momentum from small to large radii and from higher to lower latitudes, which causes the expansion of the heating region due to the extra centrifugal force. This then enhances the efficiency of neutrino heating and eventually leads to neutrino-driven explosion. This is a new scenario of core-collapse supernovae that has never been demonstrated by past numerical simulations.

  14. THE PHYSICS OF THE NEUTRINO MECHANISM OF CORE-COLLAPSE SUPERNOVAE

    SciTech Connect (OSTI)

    Pejcha, Ondrej; Thompson, Todd A.

    2012-02-10

    Although it is known that the stalled accretion shock in models of core-collapse supernovae turns into explosion when the neutrino luminosity from the proto-neutron star (PNS) exceeds a critical value (L{sup crit}{sub {nu},core}) (the 'neutrino mechanism'), the physics of L{sup crit}{sub {nu},core} has never been systematically explored. We solve the accretion problem between the PNS surface and the accretion shock. We quantify the deep connection between the general problem of accretion flows with bounding shocks and the neutrino mechanism. In particular, we show that there is a maximum, critical sound speed above which the shock jump conditions cannot be satisfied and steady-state accretion is impossible. This physics is general and does not depend on a specific heating mechanism. For the simple model of pressure-less free fall onto a shock bounding an isothermal accretion flow, we show that shock solutions are possible only for sound speed c{sub T} < c{sup crit}{sub T} and that c{sup 2}{sub T}/v{sub esc}{sup 2} = 3/16 = 0.1875 at c{sup crit}{sub T}. We generalize this result to the supernova problem, showing that the same physics determines L{sup crit}{sub {nu},core}. The critical condition for explosion can be written as c{sup 2}{sub S}/v{sup 2}{sub esc} {approx_equal} 0.19, where c{sub S} is the adiabatic sound speed. This 'antesonic' condition describes L{sup crit}{sub {nu},core} over a broad range of parameters, and other criteria proposed in the literature fail to capture this physics. We show that the accretion luminosity reduces L{sup crit}{sub {nu},core} non-trivially. A larger PNS radius decreases L{sup crit}{sub {nu},core}, implying that a stiff high-density equation of state may be preferred. Finally, using an analytic model, we provide evidence that the reduction of L{sup crit}{sub {nu},core} seen in recent multi-dimensional simulations results from reduced cooling efficiency, rather than an increased heating rate.

  15. Multi-epoch very long baseline interferometric observations of the nuclear starburst region of NGC 253: Improved modeling of the supernova and star formation rates

    SciTech Connect (OSTI)

    Rampadarath, H.; Morgan, J. S.; Tingay, S. J.; Lenc, E.

    2014-01-01

    The results of multi-epoch observations of the southern starburst galaxy, NGC 253, with the Australian Long Baseline Array at 2.3 GHz are presented. As with previous radio interferometric observations of this galaxy, no new sources were discovered. By combining the results of this survey with Very Large Array observations at higher frequencies from the literature, spectra were derived and a free-free absorption model was fitted of 20 known sources in NGC 253. The results were found to be consistent with previous studies. The supernova remnant, 5.48-43.3, was imaged with the highest sensitivity and resolution to date, revealing a two-lobed morphology. Comparisons with previous observations of similar resolution give an upper limit of 10{sup 4} km s{sup 1} for the expansion speed of this remnant. We derive a supernova rate of <0.2 yr{sup 1} for the inner 300 pc using a model that improves on previous methods by incorporating an improved radio supernova peak luminosity distribution and by making use of multi-wavelength radio data spanning 21 yr. A star formation rate of SFR(M ? 5 M {sub ?}) < 4.9 M {sub ?} yr{sup 1} was also estimated using the standard relation between supernova and star formation rates. Our improved estimates of supernova and star formation rates are consistent with studies at other wavelengths. The results of our study point to the possible existence of a small population of undetected supernova remnants, suggesting a low rate of radio supernova production in NGC 253.

  16. Constraints for the progenitor masses of 17 historic core-collapse supernovae

    SciTech Connect (OSTI)

    Williams, Benjamin F.; Peterson, Skyler; Gilbert, Karoline; Dalcanton, Julianne J.; Murphy, Jeremiah; Dolphin, Andrew E.; Jennings, Zachary G. E-mail: peters8@uw.edu E-mail: jeremiah@physics.fsu.edu E-mail: dolphin@raytheon.com

    2014-08-20

    Using resolved stellar photometry measured from archival Hubble Space Telescope imaging, we generate color-magnitude diagrams of the stars within 50 pc of the locations of historic core-collapse supernovae (SNe) that took place in galaxies within 8 Mpc. We fit these color-magnitude distributions with stellar evolution models to determine the best-fit age distribution of the young population. We then translate these age distributions into probability distributions for the progenitor mass of each SN. The measurements are anchored by the main-sequence stars surrounding the event, making them less sensitive to assumptions about binarity, post-main-sequence evolution, or circumstellar dust. We demonstrate that, in cases where the literature contains masses that have been measured from direct imaging, our measurements are consistent with (but less precise than) these measurements. Using this technique, we constrain the progenitor masses of 17 historic SNe, 11 of which have no previous estimates from direct imaging. Our measurements still allow the possibility that all SN progenitor masses are <20 M {sub ☉}. However, the large uncertainties for the highest-mass progenitors also allow the possibility of no upper-mass cutoff.

  17. Three dimensional core-collapse supernova simulated using a 15 M⊙ progenitor

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lentz, Eric J.; Bruenn, Stephen W.; Hix, W. Raphael; Mezzacappa, Anthony; Messer, O. E. Bronson; Endeve, Eirik; Blondin, John M.; Harris, J. Austin; Marronetti, Pedro; Yakunin, Konstantin N.

    2015-07-10

    We have performed ab initio neutrino radiation hydrodynamics simulations in three and two spatial dimensions (3D and 2D) of core-collapse supernovae from the same 15 M⊙ progenitor through 440 ms after core bounce. Both 3D and 2D models achieve explosions; however, the onset of explosion (shock revival) is delayed by ~100 ms in 3D relative to the 2D counterpart and the growth of the diagnostic explosion energy is slower. This is consistent with previously reported 3D simulations utilizing iron-core progenitors with dense mantles. In the ~100 ms before the onset of explosion, diagnostics of neutrino heating and turbulent kinetic energymore » favor earlier explosion in 2D. During the delay, the angular scale of convective plumes reaching the shock surface grows and explosion in 3D is ultimately lead by a single, large-angle plume, giving the expanding shock a directional orientation not dissimilar from those imposed by axial symmetry in 2D simulations. Finally, we posit that shock revival and explosion in the 3D simulation may be delayed until sufficiently large plumes form, whereas such plumes form more rapidly in 2D, permitting earlier explosions.« less

  18. SUPERNOVAE IN THE CENTRAL PARSEC: A MECHANISM FOR PRODUCING SPATIALLY ANISOTROPIC HYPERVELOCITY STARS

    SciTech Connect (OSTI)

    Zubovas, Kastytis; Wynn, Graham A.; Gualandris, Alessia

    2013-07-10

    Several tens of hypervelocity stars (HVSs) have been discovered escaping our Galaxy. These stars share a common origin in the Galactic center and are distributed anisotropically in Galactic longitude and latitude. We examine the possibility that HVSs may be created as the result of supernovae (SNe) occurring within binary systems in a disk of stars around Sgr A* over the last 100 Myr. Monte Carlo simulations show that the rate of binary disruption is {approx}10{sup -4} yr{sup -1}, comparable to that of tidal disruption models. The SN-induced HVS production rate ({Gamma}{sub HVS}) is significantly increased if the binaries are hardened via migration through a gaseous disk. Moderate hardening gives {Gamma}{sub HVS} {approx_equal} 2 Multiplication-Sign 10{sup -7} yr{sup -1} and an estimated population of {approx}20 HVSs in the last 100 Myr. SN-induced HVS production requires the internal and external orbital velocity vectors of the secondary binary component to be aligned when the binary is disrupted. This leaves an imprint of the disk geometry on the spatial distribution of the HVSs, producing a distinct anisotropy.

  19. Parametric study of flow patterns behind the standing accretion shock wave for core-collapse supernovae

    SciTech Connect (OSTI)

    Iwakami, Wakana; Nagakura, Hiroki; Yamada, Shoichi

    2014-05-10

    In this study, we conduct three-dimensional hydrodynamic simulations systematically to investigate the flow patterns behind the accretion shock waves that are commonly formed in the post-bounce phase of core-collapse supernovae. Adding small perturbations to spherically symmetric, steady, shocked accretion flows, we compute the subsequent evolutions to find what flow pattern emerges as a consequence of hydrodynamical instabilities such as convection and standing accretion shock instability for different neutrino luminosities and mass accretion rates. Depending on these two controlling parameters, various flow patterns are indeed realized. We classify them into three basic patterns and two intermediate ones; the former includes sloshing motion (SL), spiral motion (SP), and multiple buoyant bubble formation (BB); the latter consists of spiral motion with buoyant-bubble formation (SPB) and spiral motion with pulsationally changing rotational velocities (SPP). Although the post-shock flow is highly chaotic, there is a clear trend in the pattern realization. The sloshing and spiral motions tend to be dominant for high accretion rates and low neutrino luminosities, and multiple buoyant bubbles prevail for low accretion rates and high neutrino luminosities. It is interesting that the dominant pattern is not always identical between the semi-nonlinear and nonlinear phases near the critical luminosity; the intermediate cases are realized in the latter case. Running several simulations with different random perturbations, we confirm that the realization of flow pattern is robust in most cases.

  20. Stochasticity and efficiency of convection-dominated vs. SASI-dominated supernova explosions

    SciTech Connect (OSTI)

    Cardall, Christian Y.; Budiardja, Reuben D.

    2015-10-22

    We present an initial report on 160 simulations of a highly simplified model of the post-bounce supernova environment in three position space dimensions (3D). We set different values of a parameter characterizing the impact of nuclear dissociation at the stalled shock in order to regulate the post-shock fluid velocity, thereby determining the relative importance of convection and the stationary accretion shock instability (SASI). While our convection-dominated runs comport with the paradigmatic notion of a `critical neutrino luminosity' for explosion at a given mass accretion rate (albeit with a nontrivial spread in explosion times just above threshold), the outcomes of our SASI-dominated runs are more stochastic: a sharp threshold critical luminosity is `smeared out' into a rising probability of explosion over a $\\sim 20\\%$ range of luminosity. We also find that the SASI-dominated models are able to explode with 3 to 4 times less efficient neutrino heating, indicating that progenitor properties, and fluid and neutrino microphysics, conducive to the SASI would make the neutrino-driven explosion mechanism more robust.

  1. Stochasticity and efficiency of convection-dominated vs. SASI-dominated supernova explosions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Cardall, Christian Y.; Budiardja, Reuben D.

    2015-10-22

    We present an initial report on 160 simulations of a highly simplified model of the post-bounce supernova environment in three position space dimensions (3D). We set different values of a parameter characterizing the impact of nuclear dissociation at the stalled shock in order to regulate the post-shock fluid velocity, thereby determining the relative importance of convection and the stationary accretion shock instability (SASI). While our convection-dominated runs comport with the paradigmatic notion of a `critical neutrino luminosity' for explosion at a given mass accretion rate (albeit with a nontrivial spread in explosion times just above threshold), the outcomes of our SASI-dominated runs are more stochastic: a sharp threshold critical luminosity is `smeared out' into a rising probability of explosion over amore » $$\\sim 20\\%$$ range of luminosity. We also find that the SASI-dominated models are able to explode with 3 to 4 times less efficient neutrino heating, indicating that progenitor properties, and fluid and neutrino microphysics, conducive to the SASI would make the neutrino-driven explosion mechanism more robust.« less

  2. LATE-TIME OBSERVATIONS OF GRB 080319B: JET BREAK, HOST GALAXY, AND ACCOMPANYING SUPERNOVA

    SciTech Connect (OSTI)

    Tanvir, N. R.; O'Brien, P. T.; Wiersema, K.; Starling, R. L. C.; Rol, E.; Levan, A. J.; Svensson, K.; Fruchter, A. S.; Granot, J.; Jakobsson, P.; Fynbo, J.; Hjorth, J.; Curran, P. A.; Burrows, D. N.; Genet, F.

    2010-12-10

    The Swift-discovered GRB 080319B was by far the most distant source ever observed at naked-eye brightness, reaching a peak apparent magnitude of 5.3 at a redshift of z = 0.937. We present our late-time optical (Hubble Space Telescope, Gemini, and Very Large Telescope) and X-ray (Chandra) observations, which confirm that an achromatic break occurred in the power-law afterglow light curve at {approx}11 days post-burst. This most likely indicates that the gamma-ray burst (GRB) outflow was collimated, which for a uniform jet would imply a total energy in the jet E{sub jet} {approx}> 10{sup 52} erg. Our observations also show a late-time excess of red light, which is well explained if the GRB was accompanied by a supernova (SN), similar to those seen in some other long-duration GRBs. The latest observations are dominated by light from the host and show that the GRB took place in a faint dwarf galaxy (r(AB) {approx} 27.0, rest frame M{sub B} {approx} -17.2). This galaxy is small even by the standards of other GRB hosts, which is suggestive of a low-metallicity environment. Intriguingly, the properties of this extreme event-a small host and bright SN-are entirely typical of the very low luminosity bursts such as GRB 980425 and GRB 060218.

  3. NanoSIMS, TEM, and XANES studies of a unique presolar supernova graphite grain

    SciTech Connect (OSTI)

    Groopman, Evan; Bernatowicz, Thomas; Zinner, Ernst; Nittler, Larry R.

    2014-07-20

    We report on isotopic and microstructural investigations of a unique presolar supernova (SN) graphite grain, referred to as G6, isolated from the Orgueil CI chondrite. G6 contains complex heterogeneities in its isotopic composition and in its microstructure. Nano-scale secondary ion mass spectrometer isotope images of ultramicrotome sections reveal heterogeneities in its C, N, and O isotopic compositions, including anomalous shell-like structures. Transmission electron microscope studies reveal a nanocrystalline core surrounded by a turbostratic graphite mantle, the first reported nanocrystalline core from a low-density SN graphite grain. Electron diffraction analysis shows that the nanocrystalline core consists of randomly oriented 2-4 nm graphene particles, similar to those in cores of high-density (HD) presolar graphite grains from asymptotic giant branch stars. G6's core also exhibits evidence for planar stacking of these graphene nano-sheets with a domain size up to 4.5 nm, which was unobserved in the nanocrystalline cores of HD graphite grains. We also report on X-ray absorption near-edge structure measurements of G6. The complex isotopic- and micro-structure of G6 provides evidence for mixing and/or granular transport in SN ejecta.

  4. The outcome of supernovae in massive binaries; removed mass, and its separation dependence

    SciTech Connect (OSTI)

    Hirai, Ryosuke; Sawai, Hidetomo; Yamada, Shoichi [Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo 169-8555 (Japan)

    2014-09-01

    The majority of massive stars are formed in binary systems. It is hence reasonable to expect that most core-collapse supernovae (CCSNe) take place in binaries and the existence of a companion star may leave some imprints in observed features. Having this in mind, we have conducted two-dimensional hydrodynamical simulations of the collisions of CCSNe ejecta with the companion star in an almost-equal-mass (?10 M {sub ?}) binary to find out possible consequences of such events. In particular we pay attention to the amount of mass removed and its dependence on the binary separation. In contrast to the previous surmise, we find that the companion mass is stripped not by momentum transfer but by shock heating. Up to 25% of the original mass can be removed for the closest separations and the removed mass decreases as M {sub ub}?a {sup 4.3} with the binary separation a. By performing some experimental computations with artificially modified densities of incident ejecta, we show that if the velocity of ejecta is fixed, the density of incident ejecta is the single important parameter that actually determines the removed mass as M{sub ub}??{sub ej}{sup 1.4}. On the other hand, another set of simulations with modified velocities of incident ejecta demonstrate that the strength of the forward shock, which heats up the stellar material and causes the mass loss of the companion star, is actually the key parameter for the removed mass.

  5. Impacts of rotation on three-dimensional hydrodynamics of core-collapse supernovae

    SciTech Connect (OSTI)

    Nakamura, Ko; Kuroda, Takami; Kotake, Kei [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Takiwaki, Tomoya [Center for Computational Astrophysics, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2014-09-20

    We perform a series of simplified numerical experiments to explore how rotation impacts the three-dimensional (3D) hydrodynamics of core-collapse supernovae. For our systematic study, we employ a light-bulb scheme to trigger explosions and a three-flavor neutrino leakage scheme to treat deleptonization effects and neutrino losses from the proto-neutron-star interior. Using a 15 M {sub ?} progenitor, we compute 30 models in 3D with a wide variety of initial angular momentum and light-bulb neutrino luminosity. We find that the rotation can help the onset of neutrino-driven explosions for the models in which the initial angular momentum is matched to that obtained in recent stellar evolutionary calculations (?0.3-3 rad s{sup 1} at the center). For the models with larger initial angular momentum, the shock surface deforms to be more oblate due to larger centrifugal force. This not only makes the gain region more concentrated around the equatorial plane, but also makes the mass larger in the gain region. As a result, buoyant bubbles tend to be coherently formed and rise in the equatorial region, which pushes the revived shock toward ever larger radii until a global explosion is triggered. We find that these are the main reasons that the preferred direction of the explosion in 3D rotating models is often perpendicular to the spin axis, which is in sharp contrast to the polar explosions around the axis that were obtained in previous two-dimensional simulations.

  6. CONSTRAINING THE EVOLUTIONARY FATE OF CENTRAL COMPACT OBJECTS: ''OLD'' RADIO PULSARS IN SUPERNOVA REMNANTS

    SciTech Connect (OSTI)

    Bogdanov, Slavko [Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Ng, C.-Y. [Department of Physics, The University of Hong Kong, Pokfulam Road (Hong Kong); Kaspi, Victoria M., E-mail: slavko@astro.columbia.edu [Department of Physics, McGill University, 3600 University Street, Montreal, QC H3A 2T8 (Canada)

    2014-09-10

    Central compact objects (CCOs) constitute a population of radio-quiet, slowly spinning (?100ms) young neutron stars with anomalously high thermal X-ray luminosities. Their spin-down properties imply weak dipole magnetic fields (?10{sup 10-11}G) and characteristic ages much greater than the ages of their host supernova remnants (SNRs). However, CCOs may posses strong ''hidden'' internal magnetic fields that may re-emerge on timescales of ?10kyr, with the neutron star possibly activating as a radio pulsar in the process. This suggests that the immediate descendants of CCOs may be masquerading as slowly spinning ''old'' radio pulsars. We present an X-ray survey of all ordinary radio pulsars within 6kpc that are positionally coincident with Galactic SNRs in order to test the possible connection between the supposedly old but possibly very young pulsars and the SNRs. None of the targets exhibit anomalously high thermal X-ray luminosities, suggesting that they are genuine old ordinary pulsars unrelated to the superposed SNRs. This implies that CCOs are either latent radio pulsars that activate long after their SNRs dissipate or they remain permanently radio-quiet. The true descendants of CCOs remain at large.

  7. HIGH-ENERGY NEUTRINO AND GAMMA-RAY TRANSIENTS FROM TRANS-RELATIVISTIC SUPERNOVA SHOCK BREAKOUTS

    SciTech Connect (OSTI)

    Kashiyama, Kazumi; Gao, Shan; Meszaros, Peter [Center for Particle and Gravitational Astrophysics, Department of Astronomy and Astrophysics, Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Murase, Kohta; Horiuchi, Shunsaku, E-mail: kzk15@psu.edu [CCAPP and Department of Physics, Ohio State University, 191 W. Woodruff Avenue, Columbus, OH 43210 (United States)

    2013-05-20

    Trans-relativistic shocks that accompany some supernovae (SNe) produce X-ray burst emissions as they break out in the dense circumstellar medium around the progenitors. This phenomenon is sometimes associated with peculiar low-luminosity gamma-ray bursts (LL GRBs). Here, we investigate the high-energy neutrino and gamma-ray counterparts of such a class of SNe. Just beyond the shock breakout radius, particle acceleration in the collisionless shock starts to operate in the presence of breakout photons. We show that protons may be accelerated to sufficiently high energies and produce high-energy neutrinos and gamma rays via the photomeson interaction. These neutrinos and gamma rays may be detectable from {approx}< 10 Mpc away by IceCube/KM3Net as multi-TeV transients almost simultaneously with the X-ray breakout, and even from {approx}< 100 Mpc away with follow-up observations by the Cherenkov Telescope Array using a wide-field sky monitor like Swift as a trigger. A statistical technique using a stacking approach could also be possible for the detection, with the aid of the SN optical/infrared counterparts. Such multi-messenger observations offer the possibility to probe the transition of trans-relativistic shocks from radiation-mediated to collisionless ones, and would also constrain the mechanisms of particle acceleration and emission in LL GRBs.

  8. Turbulence patterns and neutrino flavor transitions in high-resolution supernova models

    SciTech Connect (OSTI)

    Borriello, Enrico; Mirizzi, Alessandro [II. Institut fr Theoretische Physik, Universitt Hamburg, Luruper Chaussee 149, D-22761 Hamburg (Germany); Chakraborty, Sovan [Max-Planck-Institut fr Physik (Werner-Heisenberg-Institut), Fhringer Ring 6, D-80805 Mnchen (Germany); Janka, Hans-Thomas [Max-Planck-Institut fr Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching (Germany); Lisi, Eligio, E-mail: enrico.borriello@desy.de, E-mail: sovan@mppmu.mpg.de, E-mail: thj@mpa-garching.mpg.de, E-mail: eligio.lisi@ba.infn.it, E-mail: alessandro.mirizzi@desy.de [INFNSezione di Bari, Via Orabona 4, 70126 Bari (Italy)

    2014-11-01

    During the shock-wave propagation in a core-collapse supernova (SN), matter turbulence may affect neutrino flavor conversion probabilities. Such effects have been usually studied by adding parametrized small-scale random fluctuations (with arbitrary amplitude) on top of coarse, spherically symmetric matter density profiles. Recently, however, two-dimensional (2D) SN models have reached a space resolution high enough to directly trace anisotropic density profiles, down to scales smaller than the typical neutrino oscillation length. In this context, we analyze the statistical properties of a large set of SN matter density profiles obtained in a high-resolution 2D simulation, focusing on a post-bounce time (2 s) suited to study shock-wave effects on neutrino propagation on scales as small as O(100) km and possibly below. We clearly find the imprint of a broken (Kolmogorov-Kraichnan) power-law structure, as generically expected in 2D turbulence spectra. We then compute the flavor evolution of SN neutrinos along representative realizations of the turbulent matter density profiles, and observe no or modest damping of the neutrino crossing probabilities on their way through the shock wave. In order to check the effect of possibly unresolved fluctuations at scales below O(100) km, we also apply a randomization procedure anchored to the power spectrum calculated from the simulation, and find consistent results within 1? fluctuations. These results show the importance of anchoring turbulence effects on SN neutrinos to realistic, fine-grained SN models.

  9. THE DOUBLE PULSAR: EVIDENCE FOR NEUTRON STAR FORMATION WITHOUT AN IRON CORE-COLLAPSE SUPERNOVA

    SciTech Connect (OSTI)

    Ferdman, R. D.; Kramer, M.; Stappers, B. W.; Lyne, A. G.; Stairs, I. H.; Breton, R. P.; McLaughlin, M. A.; Freire, P. C. C.; Possenti, A.; Kaspi, V. M.; Manchester, R. N.

    2013-04-10

    The double pulsar system PSR J0737-3039A/B is a double neutron star binary, with a 2.4 hr orbital period, which has allowed measurement of relativistic orbital perturbations to high precision. The low mass of the second-formed neutron star, as well as the low system eccentricity and proper motion, point to a different evolutionary scenario compared to most other known double neutron star systems. We describe analysis of the pulse profile shape over 6 years of observations and present the resulting constraints on the system geometry. We find the recycled pulsar in this system, PSR J0737-3039A, to be a near-orthogonal rotator with an average separation between its spin and magnetic axes of 90 Degree-Sign {+-} 11 Degree-Sign {+-} 5 Degree-Sign . Furthermore, we find a mean 95% upper limit on the misalignment between its spin and orbital angular momentum axes of 3. Degree-Sign 2, assuming that the observed emission comes from both magnetic poles. This tight constraint lends credence to the idea that the supernova that formed the second pulsar was relatively symmetric, possibly involving electron capture onto an O-Ne-Mg core.

  10. Testing the copernican principle via cosmological observations

    SciTech Connect (OSTI)

    Bolejko, Krzysztof; Wyithe, J. Stuart B. E-mail: swyithe@unimelb.edu.au

    2009-02-15

    Observations of distances to Type-Ia supernovae can be explained by cosmological models that include either a gigaparsec-scale void, or a cosmic flow, without the need for Dark Energy. Instead of invoking dark energy, these inhomogeneous models instead violate the Copernican Principle. we show that current cosmological observations (Supernovae, Baryon Acoustic Oscillations and estimates of the Hubble parameters based on the age of the oldest stars) are not able to rule out inhomogeneous anti-Copernican models. The next generation of surveys for baryonic acoustic oscillations will be sufficiently precise to either validate the Copernican Principle or determine the existence of a local Gpc scale inhomogeneity.

  11. Nonthermal radiation of young supernova remnants: The case of Cas A

    SciTech Connect (OSTI)

    Zirakashvili, V. N.; Aharonian, F. A.; Yang, R.; Oa-Wilhelmi, E.; Tuffs, R. J.

    2014-04-20

    The processes responsible for the broadband radiation of the young supernova remnant Cas A are explored by using a new code that is designed for a detailed treatment of the diffusive shock acceleration of particles in the nonlinear regime. The model is based on spherically symmetric hydrodynamic equations complemented with transport equations for relativistic particles. Electrons, protons, and the oxygen ions accelerated by forward and reverse shocks are included in the numerical calculations. We show that the available multi-wavelength observations in the radio, X-ray, and gamma-ray bands can be best explained by invoking particle acceleration by both forward and reversed shocks. Although the TeV gamma-ray observations can be interpreted by interactions of both accelerated electrons and protons/ions, the measurements by Fermi Large Area Telescope at energies below 1 GeV give a tentative preference to the hadronic origin of gamma-rays. Then, the acceleration efficiency in this source, despite the previous claims, should be very high; 25% of the explosion energy (or approximately 3 10{sup 50} erg) should already be converted to cosmic rays, mainly by the forward shock. At the same time, the model calculations do not provide extension of the maximum energy of accelerated protons beyond 100 TeV. In this model, the acceleration of electrons is dominated by the reverse shock; the required 10{sup 48} erg can be achieved under the assumption that the injection of electrons (positrons) is supported by the radioactive decay of {sup 44}Ti.

  12. EVOLUTION OF THE RADIO REMNANT OF SUPERNOVA 1987A: MORPHOLOGICAL CHANGES FROM DAY 7000

    SciTech Connect (OSTI)

    Ng, C.-Y.; Zanardo, G.; Potter, T. M.; Staveley-Smith, L.; Gaensler, B. M.; Manchester, R. N.; Tzioumis, A. K.

    2013-11-10

    We present radio imaging observations of supernova remnant 1987A at 9 GHz, taken with the Australia Telescope Compact Array over 21 years from 1992 to 2013. By employing a Fourier modeling technique to fit the visibility data, we show that the remnant structure has evolved significantly since day 7000 (mid-2006): the emission latitude has gradually decreased such that the overall geometry has become more similar to a ring structure. Around the same time, we find a decreasing trend in the east-west asymmetry of the surface emissivity. These results could reflect the increasing interaction of the forward shock with material around the circumstellar ring, and the relative weakening of the interaction with the lower-density material at higher latitudes. The morphological evolution caused an apparent break in the remnant expansion measured with a torus model, from a velocity of 4600{sup +150}{sub -}200 km s{sup 1} between day 4000 and 7000 to 2400{sup +100}{sub -200} km s{sup 1} after day 7000. However, we emphasize that there is no conclusive evidence for a physical slowing of the shock at any given latitude in the expanding remnant, and that a change of radio morphology alone appears to dominate the evolution. This is supported by our ring-only fits which show a constant expansion of 3890 50 km s{sup 1} without deceleration between days 4000 and 9000. We suggest that once the emission latitude no longer decreases, the expansion velocity obtained from the torus model should return to the same value as that measured with the ring model.

  13. Spectral and morphological analysis of the remnant of supernova 1987A with ALMA and ATCA

    SciTech Connect (OSTI)

    Zanardo, Giovanna; Staveley-Smith, Lister [International Centre for Radio Astronomy Research (ICRAR), M468, University of Western Australia, Crawley, WA 6009 (Australia); Indebetouw, Remy; Chevalier, Roger A. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Matsuura, Mikako; Barlow, Michael J. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Gaensler, Bryan M. [Australian Research Council, Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia); Fransson, Claes; Lundqvist, Peter [Department of Astronomy, Oskar Klein Center, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Manchester, Richard N. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia); Baes, Maarten [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Kamenetzky, Julia R. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065 (United States); Laki?evi?, Maa [Institute for the Environment, Physical Sciences and Applied Mathematics, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG (United Kingdom); Marcaide, Jon M. [Departamento de Astronoma, Universidad de Valencia, C/Dr. Moliner 50, E-46100 Burjassot (Spain); Mart-Vidal, Ivan [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala (Sweden); Meixner, Margaret [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Ng, C.-Y. [Department of Physics, University of Hong Kong, Pokfulam Road, Hong Kong (China); Park, Sangwook, E-mail: giovanna.zanardo@gmail.com [Department of Physics, University of Texas at Arlington, 108 Science Hall, Box 19059, Arlington, TX 76019 (United States); and others

    2014-12-01

    We present a comprehensive spectral and morphological analysis of the remnant of supernova (SN) 1987A with the Australia Telescope Compact Array (ATCA) and the Atacama Large Millimeter/submillimeter Array (ALMA). The non-thermal and thermal components of the radio emission are investigated in images from 94 to 672 GHz (? 3.2 mm to 450 ?m), with the assistance of a high-resolution 44 GHz synchrotron template from the ATCA, and a dust template from ALMA observations at 672 GHz. An analysis of the emission distribution over the equatorial ring in images from 44 to 345 GHz highlights a gradual decrease of the east-to-west asymmetry ratio with frequency. We attribute this to the shorter synchrotron lifetime at high frequencies. Across the transition from radio to far infrared, both the synchrotron/dust-subtracted images and the spectral energy distribution (SED) suggest additional emission beside the main synchrotron component (S {sub ?}??{sup 0.73}) and the thermal component originating from dust grains at T ? 22 K. This excess could be due to free-free flux or emission from grains of colder dust. However, a second flat-spectrum synchrotron component appears to better fit the SED, implying that the emission could be attributed to a pulsar wind nebula (PWN). The residual emission is mainly localized west of the SN site, as the spectral analysis yields 0.4 ? ? ? 0.1 across the western regions, with ? ? 0 around the central region. If there is a PWN in the remnant interior, these data suggest that the pulsar may be offset westward from the SN position.

  14. Escape fraction of ionizing photons during reionization: Effects due to supernova feedback and runaway ob stars

    SciTech Connect (OSTI)

    Kimm, Taysun; Cen, Renyue

    2014-06-20

    The fraction of hydrogen ionizing photons escaping from galaxies into the intergalactic medium is a critical ingredient in the theory of reionization. We use two zoomed-in, high-resolution (4 pc), cosmological radiation hydrodynamic simulations with adaptive mesh refinement to investigate the impact of two physical mechanisms (supernova, SN, feedback, and runaway OB stars) on the escape fraction (f {sub esc}) at the epoch of reionization (z ? 7). We implement a new, physically motivated SN feedback model that can approximate the Sedov solutions at all (from the free expansion to snowplow) stages. We find that there is a significant time delay of about ten million years between the peak of star formation and that of escape fraction, due to the time required for the build-up and subsequent destruction of the star-forming cloud by SN feedback. Consequently, the photon number-weighted mean escape fraction for dwarf galaxies in halos of mass 10{sup 8}-10{sup 10.5} M {sub ?} is found to be ?f{sub esc}??11%, although instantaneous values of f {sub esc} > 20% are common when star formation is strongly modulated by the SN explosions. We find that the inclusion of runaway OB stars increases the mean escape fraction by 22% to ?f{sub esc}??14%. As SNe resulting from runaway OB stars tend to occur in less dense environments, the feedback effect is enhanced and star formation is further suppressed in halos with M{sub vir}?10{sup 9} M{sub ?} in the simulation with runaway OB stars compared with the model without them. While both our models produce enough ionizing photons to maintain a fully ionized universe at z ? 7 as observed, a still higher amount of ionizing photons at z ? 9 appears necessary to accommodate the high observed electron optical depth inferred from cosmic microwave background observations.

  15. Strangeness driven phase transitions in compressed baryonic matter and their relevance for neutron stars and core collapsing supernovae

    SciTech Connect (OSTI)

    Raduta, Ad. R.; Gulminelli, F.; Oertel, M.

    2015-02-24

    We discuss the thermodynamics of compressed baryonic matter with strangeness within non-relativistic mean-field models with effective interactions. The phase diagram of the full baryonic octet under strangeness equilibrium is built and discussed in connection with its relevance for core-collapse supernovae and neutron stars. A simplified framework corresponding to (n, p, Λ)(+e)-mixtures is employed in order to test the sensitivity of the existence of a phase transition on the (poorely constrained) interaction coupling constants and the compatibility between important hyperonic abundances and 2M{sub ⊙} neutron stars.

  16. Gorchakova-IA

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Atl anta, Georgia, March 19-23, 2001 1 Estimate of Horizontal Cloud Inhomogeneity Effect on Solar Radiative Fluxes for Conditions of Winter Zvenigorod Experiment I. A. Gorchakova, G. S. Golitsyn, and I. I. Mokhov Oboukhov Institute of Atmospheric Physics Russian Academy of Sciences Moscow, Russia T. B. Zhuravleva Institute of Atmospheric Optics Tomsk, Russia Introduction Study of physical phenomena determining large-scale dynamical and energetic processes in the atmosphere requires quite full

  17. IA Blog Archive

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    2014 21:03:00 +0000 921386 at http:energy.gov Ministers Meet in Addis Ababa for U.S.-Africa Energy Ministerial http:energy.goviaarticlesministers-meet-addis-ababa-us-africa-...

  18. IA News Archive

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Dilma Rousseff of Brazil and he announced the creation of a Strategic Energy Dialogue (SED) to support the two countries' common goals of developing safe, secure and affordable...

  19. Fermi-LAT Discovery of GeV Gamma-ray Emission from the Young Supernova Remnant Cassiopeia A

    SciTech Connect (OSTI)

    Abdo, A.A.

    2011-08-19

    We report on the first detection of GeV high-energy gamma-ray emission from a young supernova remnant with the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope. These observations reveal a source with no discernible spatial extension detected at a significance level of 12.2{sigma} above 500 MeV at a location that is consistent with the position of the remnant of the supernova explosion that occurred around 1680 in the Cassiopeia constellation - Cassiopeia A. The gamma-ray flux and spectral shape of the source are consistent with a scenario in which the gamma-ray emission originates from relativistic particles accelerated in the shell of this remnant. The total content of cosmic rays (electrons and protons) accelerated in Cas A can be estimated as W{sub CR} {approx_equal} (1-4) x 10{sup 49} erg thanks to the well-known density in the remnant assuming that the observed gamma-ray originates in the SNR shell(s). The magnetic field in the radio-emitting plasma can be robustly constrained as B {ge} 0.1 mG, providing new evidence of the magnetic field amplification at the forward shock and the strong field in the shocked ejecta.

  20. THE MID-INFRARED LIGHT CURVE OF NEARBY CORE-COLLAPSE SUPERNOVA SN 2011dh (PTF 11eon)

    SciTech Connect (OSTI)

    Helou, George; Surace, Jason; Kasliwal, Mansi M.; Ofek, Eran O.; Arcavi, Iair; Gal-Yam, Avishay

    2013-11-20

    We present Spitzer observations at 3.6 and 4.5 μm of the supernova SN 2011dh (PTF 11eon) in M51 from 18 days to 625 days after explosion. The mid-infrared emission peaks at 24 days after explosion at a few ×10{sup 7} L {sub ☉}, and decays more slowly than the visible-light bolometric luminosity. The infrared color temperature cools for the first 90 days and then is constant. Simple numerical models of a thermal echo can qualitatively reproduce the early behavior. At late times, the mid-IR light curve cannot be explained by a simple thermal echo model, suggesting additional dust heating or line emission mechanisms. We also propose that thermal echoes can serve as effective probes to uncover supernovae in heavily obscured environments, and speculate that under the right conditions, integrating the early epoch of the mid-infrared light curve may constrain the total energy in the shock breakout flash.

  1. Ravi R. Gupta | Argonne National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ravi R. Gupta Postdoctoral Appointee Dr. Ravi Gupta is a postdoc studying Type Ia supernovae and their host galaxies as part of the Dark Energy Survey (www.darkenergysurvey.org). He also spends part of his time nanofabricating ring resonators at Argonne's Center for Nanoscale Materials (www.anl.gov/cnm/) for future near-infrared astronomy applications. EDUCATION Ph.D. in Physics & Astronomy, University of Pennsylvania, 2013 B.S. in Physics, Stanford University, 2007 Telephone (630) 252-6218

  2. Distance Probes of Dark Energy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kim, A. G.; Padmanabhan, N.; Aldering, G.; Allen, S. W.; Baltay, C.; Cahn, R. N.; D' Andrea, C. B.; Dalal, N.; Dawson, K. S.; Denney, K. D.; et al

    2015-03-15

    We present the results from the Distances subgroup of the Cosmic Frontier Community Planning Study (Snowmass 2013). This document summarizes the current state of the field as well as future prospects and challenges. In addition to the established probes using Type Ia supernovae and baryon acoustic oscillations, we also consider prospective methods based on clusters, active galactic nuclei, gravitational wave sirens and strong lensing time delays.

  3. Computer Code Gives Astrophysicists First Full Simulation of Star's Final Hours

    ScienceCinema (OSTI)

    Andy Nonaka

    2010-01-08

    The precise conditions inside a white dwarf star in the hours leading up to its explosive end as a Type Ia supernova are one of the mysteries confronting astrophysicists studying these massive stellar explosions. But now, a team of researchers, composed of three applied mathematicians at the U.S. Department of Energy's (DOE) Lawrence Berkeley National Laboratory and two astrophysicists, has created the first full-star simulation of the hours preceding the largest thermonuclear explosions in the universe.

  4. Luminosity distance for Born-Infeld electromagnetic waves propagating in a cosmological magnetic background

    SciTech Connect (OSTI)

    Aiello, Matias; Bengochea, Gabriel R; Ferraro, Rafael E-mail: gabriel@iafe.uba.ar; Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires

    2008-06-15

    Born-Infeld electromagnetic waves interacting with a static magnetic background in an expanding universe are studied. The non-linear character of Born-Infeld electrodynamics modifies the relation between the energy flux and the distance to the source, which gains a new dependence on the redshift that is governed by the background field. We compute the luminosity distance as a function of the redshift and compare with Maxwellian curves for supernovae type Ia.

  5. Observation of 23 supernovae that exploded <300 pc from Earth during the past 300 kyr

    SciTech Connect (OSTI)

    Firestone, R. B.

    2014-07-01

    Four supernovae (SNe), exploding ≤300 pc from Earth, were recorded 44, 37, 32, and 22 kyr ago in the radiocarbon ({sup 14}C) record during the past 50 kyr. Each SN left a nearly identical signature in the record, beginning with an initial sudden increase in atmospheric radiocarbon, when the SN exploded, followed by a hiatus of 1500 yr, and concluding with a sustained 2000 yr increase in global radiocarbon due to γ-rays produced by diffusive shock in the SN remnant (SNR). For the past 18 kyr excess radiocarbon has decayed with the {sup 14}C half-life. SN22kyrBP, is identified as the Vela SN that exploded 250 ± 30 pc from Earth. These SN are confirmed in the {sup 10}Be, {sup 26}Al, {sup 36}Cl, and NO{sub 3}{sup −} geologic records. The rate of near-Earth SNe is consistent with the observed rate of historical SNe giving a galactic rate of 14 ± 3 kyr{sup –1} assuming the Chandra Galactic Catalog SNR distribution. The Earth has been used as a calorimeter to determine that ≈2 × 10{sup 49} erg were released as γ-rays at the time of each SN explosion and ≈10{sup 50} erg in γ-rays following each SN. The background rate of {sup 14}C production by cosmic rays has been determined as 1.61 atoms cm{sup –2} s{sup –1}. Approximately 1/3 of the cosmic ray energy produced by diffusive shock in the SNR was observed to be emitted as high-energy γ-rays. Analysis of the {sup 10}Be/{sup 9}Be ratio in marine sediment identified 19 additional near-Earth SNe that exploded 50-300 kyr ago. Comparison of the radiocarbon record with global temperature variations indicated that each SN explosion is correlated with a concurrent global warming of ≈3°C-4°C.

  6. Revisiting impacts of nuclear burning for reviving weak shocks in neutrino-driven supernovae

    SciTech Connect (OSTI)

    Nakamura, Ko; Kotake, Kei; Takiwaki, Tomoya; Nishimura, Nobuya

    2014-02-20

    We revisit potential impacts of nuclear burning on the onset of the neutrino-driven explosions of core-collapse supernovae. By changing the neutrino luminosity and its decay time to obtain parametric explosions in one- and two-dimensional (1D and 2D, respectively) models with or without a 13 isotope ? network, we study how the inclusion of nuclear burning could affect the postbounce dynamics for 4 progenitor models; 3 for 15.0 M {sub ?} stars and 1 for an 11.2 M {sub ?} star. We find that the energy supply due to the nuclear burning of infalling material behind the shock can energize the shock expansion, especially for models that produce only marginal explosions in the absence of nuclear burning. These models are energized by nuclear energy deposition when the shock front passes through the silicon-rich layer and/or later as it touches the oxygen-rich layer. Depending on the neutrino luminosity and its decay time, the diagnostic energy of the explosion increases up to a few times 10{sup 50} erg for models with nuclear burning compared to the corresponding models without. We point out that these features are most remarkable for the Limongi-Chieffi progenitor in both 1D and 2D because the progenitor model possesses a massive oxygen layer, with an inner-edge radius that is smallest among the employed progenitors, which means that the shock can touch the rich fuel on a shorter timescale after bounce. The energy difference is generally smaller (?0.1-0.2 10{sup 51} erg) in 2D than in 1D (at most ?0.6 10{sup 51} erg). This is because neutrino-driven convection and the shock instability in 2D models enhance the neutrino heating efficiency, which makes the contribution of nuclear burning relatively smaller compared to 1D models. Considering uncertainties in progenitor models, our results indicate that nuclear burning should remain one of the important ingredients to foster the onset of neutrino-driven explosions.

  7. ON THE EXPANSION RATE, AGE, AND DISTANCE OF THE SUPERNOVA REMNANT G266.2–1.2 (Vela Jr.)

    SciTech Connect (OSTI)

    Allen, G. E.; Chow, K.; DeLaney, T.; Filipović, M. D.; Houck, J. C.; Pannuti, T. G.; Stage, M. D. E-mail: kc71135@gmail.com E-mail: m.filipovic@uws.edu.au E-mail: t.pannuti@moreheadstate.edu

    2015-01-10

    An analysis of Chandra ACIS data for two relatively bright and narrow portions of the northwestern rim of G266.2–1.2 (a.k.a. RX J0852.0-4622 or Vela Jr.) reveal evidence of a radial displacement of 2.40 ± 0.56 arcsec between 2003 and 2008. The corresponding expansion rate (0.42 ± 0.10 arcsec yr{sup –1} or 13.6% ± 4.2% kyr{sup –1}) is about half the rate reported for an analysis of XMM-Newton data from a similar, but not identical, portion of the rim over a similar, but not identical, time interval (0.84 ± 0.23 arcsec yr{sup –1}). If the Chandra rate is representative of the remnant as a whole, then the results of a hydrodynamic analysis suggest that G266.2–1.2 is between 2.4 and 5.1 kyr old if it is expanding into a uniform ambient medium (whether or not it was produced by a Type Ia or Type II event). If the remnant is expanding into the material shed by a steady stellar wind, then the age could be as much as 50% higher. The Chandra expansion rate and a requirement that the shock speed be greater than or equal to 1000 km s{sup –1} yields a lower limit on the distance of 0.5 kpc. An analysis of previously published distance estimates and constraints suggests G266.2–1.2 is no further than 1.0 kpc. This range of distances is consistent with the distance to the nearer of two groups of material in the Vela Molecular Ridge (0.7 ± 0.2 kpc) and to the Vel OB1 association (0.8 kpc)

  8. The hydrogen-poor superluminous supernova iPTF 13ajg and its host galaxy in absorption and emission

    SciTech Connect (OSTI)

    Vreeswijk, Paul M.; Gal-Yam, Avishay; De Cia, Annalisa; Rubin, Adam; Yaron, Ofer; Tal, David; Ofek, Eran O.; Savaglio, Sandra; Quimby, Robert M.; Sullivan, Mark; Cenko, S. Bradley; Filippenko, Alexei V.; Clubb, Kelsey I.; Perley, Daniel A.; Cao, Yi; Taddia, Francesco; Sollerman, Jesper; Leloudas, Giorgos; Arcavi, Iair; Kasliwal, Mansi M.; and others

    2014-12-10

    We present imaging and spectroscopy of a hydrogen-poor superluminous supernova (SLSN) discovered by the intermediate Palomar Transient Factory, iPTF 13ajg. At a redshift of z = 0.7403, derived from narrow absorption lines, iPTF 13ajg peaked at an absolute magnitude of M {sub u,} {sub AB} = –22.5, one of the most luminous supernovae to date. The observed bolometric peak luminosity of iPTF 13ajg is 3.2 × 10{sup 44} erg s{sup –1}, while the estimated total radiated energy is 1.3 × 10{sup 51} erg. We detect narrow absorption lines of Mg I, Mg II, and Fe II, associated with the cold interstellar medium in the host galaxy, at two different epochs with X-shooter at the Very Large Telescope. From Voigt profile fitting, we derive the column densities log N(Mg I) =11.94 ± 0.06, log N(Mg II) =14.7 ± 0.3, and log N(Fe II) =14.25 ± 0.10. These column densities, as well as the Mg I and Mg II equivalent widths of a sample of hydrogen-poor SLSNe taken from the literature, are at the low end of those derived for gamma-ray bursts (GRBs) whose progenitors are also thought to be massive stars. This suggests that the environments of hydrogen-poor SLSNe and GRBs are different. From the nondetection of Fe II fine-structure absorption lines, we derive a lower limit on the distance between the supernova and the narrow-line absorbing gas of 50 pc. The neutral gas responsible for the absorption in iPTF 13ajg exhibits a single narrow component with a low velocity width, ΔV = 76 km s{sup –1}, indicating a low-mass host galaxy. No host galaxy emission lines are detected, leading to an upper limit on the unobscured star formation rate (SFR) of SFR{sub [O} {sub II]}<0.07M{sub ⊙}yr{sup −1}. Late-time imaging shows the iPTF 13ajg host galaxy to be faint, with g {sub AB} ≈ 27.0 and R {sub AB} ≥ 26.0 mag, corresponding to M {sub B,} {sub Vega} ≳ –17.7 mag.

  9. ARM - Measurement - Cloud type

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Measurement : Cloud type Cloud type such as cirrus, stratus, cumulus etc Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  10. ACCELERATING VERY FAST GAS IN THE SUPERNOVA IMPOSTOR SN 2009ip WITH JETS FROM A STELLAR COMPANION

    SciTech Connect (OSTI)

    Tsebrenko, Danny; Soker, Noam E-mail: soker@physics.technion.ac.il

    2013-11-10

    Using hydrodynamic numerical simulations we show that high-velocity ejecta with v ? 10{sup 4} km s{sup 1} in the outbursts of the supernova impostor SN 2009ip and similar luminous blue variable (LBV) stars can be explained by the interaction of fast jets, having v {sub jet} ? 2000-3000 km s{sup 1}, with a circumbinary shell (extended envelope). The density profile in the shell is very steep such that the shock wave, that is excited by the jets' interaction with the shell, accelerates to high velocities as it propagates outward. The amount of very fast ejecta is small, but sufficient to account for some absorption lines. Such an extended envelope can be formed from the binary interaction and/or the unstable phase of the LBV primary star. The jets themselves are launched by the more compact secondary star near periastron passages.

  11. The initiation and propagation of helium detonations in white dwarf envelopes

    SciTech Connect (OSTI)

    Shen, Ken J. [Department of Astronomy and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States); Moore, Kevin, E-mail: kenshen@astro.berkeley.edu [Department of Applied Mathematics and Statistics, University of California, Santa Cruz, CA 95064 (United States)

    2014-12-10

    Detonations in helium-rich envelopes surrounding white dwarfs have garnered attention as triggers of faint thermonuclear '.Ia' supernovae and double detonation Type Ia supernovae. However, recent studies have found that the minimum size of a hotspot that can lead to a helium detonation is comparable to, or even larger than, the white dwarf's pressure scale height, casting doubt on the successful ignition of helium detonations in these systems. In this paper, we examine the previously neglected effects of C/O pollution and a full nuclear reaction network, and we consider hotspots with spatially constant pressure in addition to constant density hotspots. We find that the inclusion of these effects significantly decreases the minimum hotspot size for helium-rich detonation ignition, making detonations far more plausible during turbulent shell convection or during double white dwarf mergers. The increase in burning rate also decreases the minimum shell mass in which a helium detonation can successfully propagate and alters the composition of the shell's burning products. The ashes of these low-mass shells consist primarily of silicon, calcium, and unburned helium and metals and may explain the high-velocity spectral features observed in most Type Ia supernovae.

  12. The supernova progenitor mass distributions of M31 and M33: further evidence for an upper mass limit

    SciTech Connect (OSTI)

    Jennings, Zachary G.; Weisz, Daniel R.; Williams, Benjamin F.; Dalcanton, Julianne J.; Gilbert, Karoline M.; Fouesneau, Morgan; Murphy, Jeremiah W.; Dolphin, Andrew E. E-mail: adolphin@raytheon.com

    2014-11-10

    Using Hubble Space Telescope photometry to measure star formation histories, we age-date the stellar populations surrounding supernova remnants (SNRs) in M31 and M33. We then apply stellar evolution models to the ages to infer the corresponding masses for their supernova progenitor stars. We analyze 33 M33 SNR progenitors and 29 M31 SNR progenitors in this work. We then combine these measurements with 53 previously published M31 SNR progenitor measurements to bring our total number of progenitor mass estimates to 115. To quantify the mass distributions, we fit power laws of the form dN/dM∝M {sup –α}. Our new larger sample of M31 progenitors follows a distribution with α=4.4{sub −0.4}{sup +0.4}, and the M33 sample follows a distribution with α=3.8{sub −0.5}{sup +0.4}. Thus both samples are consistent within the uncertainties, and the full sample across both galaxies gives α=4.2{sub −0.3}{sup +0.3}. Both the individual and full distributions display a paucity of massive stars when compared to a Salpeter initial mass function, which we would expect to observe if all massive stars exploded as SN that leave behind observable SNR. If we instead fix α = 2.35 and treat the maximum mass as a free parameter, we find M {sub max} ∼ 35-45 M {sub ☉}, indicative of a potential maximum cutoff mass for SN production. Our results suggest that either SNR surveys are biased against finding objects in the youngest (<10 Myr old) regions, or the highest mass stars do not produce SNe.

  13. NEW HYPERON EQUATIONS OF STATE FOR SUPERNOVAE AND NEUTRON STARS IN DENSITY-DEPENDENT HADRON FIELD THEORY

    SciTech Connect (OSTI)

    Banik, Sarmistha [BITS Pilani, Hyderabad Campus, Hyderabad-500078 (India); Hempel, Matthias [Departement Physik, Universitt Basel, Klingelbergstrasse 82, 4056 Basel (Switzerland); Bandyopadhyay, Debades [Astroparticle Physics and Cosmology Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India)

    2014-10-01

    We develop new hyperon equation of state (EoS) tables for core-collapse supernova simulations and neutron stars. These EoS tables are based on a density-dependent relativistic hadron field theory where baryon-baryon interaction is mediated by mesons, using the parameter set DD2 for nucleons. Furthermore, light and heavy nuclei along with interacting nucleons are treated in the nuclear statistical equilibrium model of Hempel and Schaffner-Bielich which includes excluded volume effects. Of all possible hyperons, we consider only the contribution of ?s. We have developed two variants of hyperonic EoS tables: in the np?? case the repulsive hyperon-hyperon interaction mediated by the strange ? meson is taken into account, and in the np? case it is not. The EoS tables for the two cases encompass a wide range of densities (10{sup 12} to ?1 fm{sup 3}), temperatures (0.1 to 158.48 MeV), and proton fractions (0.01 to 0.60). The effects of ? hyperons on thermodynamic quantities such as free energy per baryon, pressure, or entropy per baryon are investigated and found to be significant at higher densities. The cold, ?-equilibrated EoS (with the crust included self-consistently) results in a 2.1 M {sub ?} maximum mass neutron star for the np?? case, whereas that for the np? case is 1.95 M {sub ?}. The np?? EoS represents the first supernova EoS table involving hyperons that is directly compatible with the recently measured 2 M {sub ?} neutron stars.

  14. PS1-12sk IS A PECULIAR SUPERNOVA FROM A He-RICH PROGENITOR SYSTEM IN A BRIGHTEST CLUSTER GALAXY ENVIRONMENT

    SciTech Connect (OSTI)

    Sanders, N. E.; Soderberg, A. M.; Foley, R. J.; Chornock, R.; Milisavljevic, D.; Margutti, R.; Drout, M. R.; Moe, M.; Berger, E.; Brown, W. R.; Lunnan, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Smartt, S. J.; Fraser, M.; Kotak, R.; Magill, L.; Smith, K. W.; Wright, D. [Astrophysics Research Centre, School of Maths and Physics, Queens University, Belfast BT7 1NN (United Kingdom); Huang, K. [Academia Sinica Institute of Astronomy and Astrophysics, Taipei 106, Taiwan (China); Urata, Y. [Institute of Astronomy, National Central University, Chung-Li 32054, Taiwan (China); Mulchaey, J. S., E-mail: nsanders@cfa.harvard.edu [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); and others

    2013-05-20

    We report on our discovery and observations of the Pan-STARRS1 supernova (SN) PS1-12sk, a transient with properties that indicate atypical star formation in its host galaxy cluster or pose a challenge to popular progenitor system models for this class of explosion. The optical spectra of PS1-12sk classify it as a Type Ibn SN (SN Ibn; cf. SN 2006jc), dominated by intermediate-width (3 Multiplication-Sign 10{sup 3} km s{sup -1}) and time variable He I emission. Our multi-wavelength monitoring establishes the rise time dt {approx} 9-23 days and shows an NUV-NIR spectral energy distribution with temperature {approx}> 17 Multiplication-Sign 10{sup 3} K and a peak magnitude of M{sub z} = -18.88 {+-} 0.02 mag. SN Ibn spectroscopic properties are commonly interpreted as the signature of a massive star (17-100 M{sub Sun }) explosion within an He-enriched circumstellar medium. However, unlike previous SNe Ibn, PS1-12sk is associated with an elliptical brightest cluster galaxy, CGCG 208-042 (z = 0.054) in cluster RXC J0844.9+4258. The expected probability of an event like PS1-12sk in such environments is low given the measured infrequency of core-collapse SNe in red-sequence galaxies compounded by the low volumetric rate of SN Ibn. Furthermore, we find no evidence of star formation at the explosion site to sensitive limits ({Sigma}{sub H{alpha}} {approx}< 2 Multiplication-Sign 10{sup -3} M{sub Sun} yr{sup -1} kpc{sup -2}). We therefore discuss white dwarf binary systems as a possible progenitor channel for SNe Ibn. We conclude that PS1-12sk represents either a fortuitous and statistically unlikely discovery, evidence for a top-heavy initial mass function in galaxy cluster cooling flow filaments, or the first clue suggesting an alternate progenitor channel for SNe Ibn.

  15. Identification campaign of supernova remnant candidates in the Milky Way. II. X-ray studies of G38.7-1.4

    SciTech Connect (OSTI)

    Huang, R. H. H.; Wu, J. H. K.; Kong, A. K. H.; Hui, C. Y.; Seo, K. A.; Trepl, L.

    2014-04-20

    We report on XMM-Newton and Chandra observations of the Galactic supernova remnant candidate G38.7-1.4, together with complementary radio, infrared, and γ-ray data. An approximately elliptical X-ray structure is found to be well correlated with a radio shell as seen by the Very Large Array. The X-ray spectrum of G38.7-1.4 can be well described by an absorbed collisional ionization equilibrium plasma model, which suggests the plasma is shock heated. Based on the morphology and the spectral behavior, we suggest that G38.7-1.4 is indeed a supernova remnant belonging to a mix-morphology category.

  16. Types of Reuse

    Broader source: Energy.gov [DOE]

    The following provides greater detail regarding the types of reuse pursued for LM sites. It should be noted that many actual reuses combine several types of the uses listed below.

  17. Types of Radiation Exposure

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    External Irradiation Contamination Incorporation Biological Effects of Acute, Total Body Irradiation Managing Radiation Emergencies Procedure Demonstration Types of radiation ...

  18. Stellar yields of rotating first stars. I. Yields of weak supernovae and abundances of carbon-enhanced hyper-metal-poor stars

    SciTech Connect (OSTI)

    Takahashi, Koh; Umeda, Hideyuki [Department of Astronomy, The University of Tokyo, Bunkyo, Tokyo 113-0033 (Japan); Yoshida, Takashi, E-mail: ktakahashi@astron.s.u-tokyo.ac.jp [Yukawa Institute for Theoretical Physics, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502 (Japan)

    2014-10-10

    We perform a stellar evolution simulation of first stars and calculate stellar yields from the first supernovae. The initial masses are taken from 12 to 140 M {sub ?} to cover the whole range of core-collapse supernova progenitors, and stellar rotation is included, which results in efficient internal mixing. A weak explosion is assumed in supernova yield calculations, thus only outer distributed matter, which is not affected by the explosive nucleosynthesis, is ejected in the models. We show that the initial mass and the rotation affect the explosion yield. All the weak explosion models have abundances of [C/O] larger than unity. Stellar yields from massive progenitors of >40-60 M {sub ?} show enhancement of Mg and Si. Rotating models yield abundant Na and Al, and Ca is synthesized in nonrotating heavy massive models of >80 M {sub ?}. We fit the stellar yields to the three most iron-deficient stars and constrain the initial parameters of the mother progenitor stars. The abundance pattern in SMSS 03136708 is well explained by 50-80 M {sub ?} nonrotating models, rotating 30-40 M {sub ?} models well fit the abundance of HE 0107-5240, and both nonrotating and rotating 15-40 M {sub ?} models explain HE 1327-2326. The presented analysis will be applicable to other carbon-enhanced hyper-metal-poor stars observed in the future. The abundance analyses will give valuable information about the characteristics of the first stars.

  19. THE FINAL FATE OF STARS THAT IGNITE NEON AND OXYGEN OFF-CENTER: ELECTRON CAPTURE OR IRON CORE-COLLAPSE SUPERNOVA?

    SciTech Connect (OSTI)

    Jones, Samuel; Hirschi, Raphael; Nomoto, Ken'ichi

    2014-12-20

    In the ONeMg cores of 8.8-9.5 M {sub ?}stars, neon and oxygen burning is ignited off-center. Whether or not the neon-oxygen flame propagates to the center is critical for determining whether these stars undergo Fe core collapse or electron-capture-induced ONeMg core collapse. We present more details of stars that ignite neon and oxygen burning off-center. The neon flame is established in a manner similar to the carbon flame of super-AGB stars, albeit with a narrower flame width. The criteria for establishing a flame can be met if the strict Schwarzschild criterion for convective instability is adopted. Mixing across the interface of the convective shell disrupts the conditions for the propagation of the burning front, and instead the shell burns as a series of inward-moving flashes. While this may not directly affect whether or not the burning will reach the center (as in super-AGB stars), the core is allowed to contract between each shell flash. Reduction of the electron fraction in the shell reduces the Chandrasekhar mass and the center reaches the threshold density for the URCA process to activate and steer the remaining evolution of the core. This highlights the importance of a more accurate treatment of mixing in the stellar interior for yet another important question in stellar astrophysicsdetermining the properties of stellar evolution and supernova progenitors at the boundary between electron capture supernova and iron core-collapse supernova.

  20. Postdoc Appointment Types

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Appointment Types Postdoc Appointment Types Most postdocs will be offered a postdoctoral research associate appointment. Each year, approximately 30 Postdoctoral Fellow appointments, including the Distinguished Fellows, are awarded. Postdoc appointment types offer world of possibilities Meet the current LANL Distinguished Postdocs Research Associates Research Associates pursue research as part of ongoing LANL science and engineering programs. Sponsored postdoctoral candidate packages are

  1. Heating from free-free absorption and the mass-loss rate of the progenitor stars to supernovae

    SciTech Connect (OSTI)

    Björnsson, C.-I.; Lundqvist, P. E-mail: peter@astro.su.se

    2014-06-01

    An accurate determination of the mass-loss rate of the progenitor stars to core-collapse supernovae is often limited by uncertainties pertaining to various model assumptions. It is shown that under conditions when the temperature of the circumstellar medium is set by heating due to free-free absorption, observations of the accompanying free-free optical depth allow a direct determination of the mass-loss rate from observed quantities in a rather model-independent way. The temperature is determined self-consistently, which results in a characteristic time dependence of the free-free optical depth. This can be used to distinguish free-free heating from other heating mechanisms. Since the importance of free-free heating is quite model dependent, this also makes possible several consistency checks of the deduced mass-loss rate. It is argued that the free-free absorption observed in SN 1993J is consistent with heating from free-free absorption. The deduced mass-loss rate of the progenitor star is, approximately, 10{sup –5} M {sub ☉} yr{sup –1} for a wind velocity of 10 km s{sup –1}.

  2. A comparison of two- and three-dimensional neutrino-hydrodynamics simulations of core-collapse supernovae

    SciTech Connect (OSTI)

    Takiwaki, Tomoya; Kotake, Kei [Center for Computational Astrophysics, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Suwa, Yudai [Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)

    2014-05-10

    We present numerical results on two- (2D) and three-dimensional (3D) hydrodynamic core-collapse simulations of an 11.2 M {sub ?} star. By changing numerical resolutions and seed perturbations systematically, we study how the postbounce dynamics are different in 2D and 3D. The calculations were performed with an energy-dependent treatment of the neutrino transport based on the isotropic diffusion source approximation scheme, which we have updated to achieve a very high computational efficiency. All of the computed models in this work, including nine 3D models and fifteen 2D models, exhibit the revival of the stalled bounce shock, leading to the possibility of explosion. All of them are driven by the neutrino-heating mechanism, which is fostered by neutrino-driven convection and the standing-accretion-shock instability. Reflecting the stochastic nature of multi-dimensional (multi-D) neutrino-driven explosions, the blast morphology changes from model to model. However, we find that the final fate of the multi-D models, whether an explosion is obtained or not, is little affected by the explosion stochasticity. In agreement with some previous studies, higher numerical resolutions lead to slower onset of the shock revival in both 2D and 3D. Based on the self-consistent supernova models leading to the possibility of explosions, our results systematically show that the revived shock expands more energetically in 2D than in 3D.

  3. A new equation of state with light nuclei and their weak interactions in core-collapse supernova simulations

    SciTech Connect (OSTI)

    Furusawa, Shun; Yamada, Shoichi [Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo 169-8555 (Japan); Nagakura, Hiroki [Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto, 606-8502 (Japan); Sumiyoshi, Kohsuke [Numazu College of Technology, Ooka 3600, Numazu, Shizuoka 410-8501 (Japan); Suzuki, Hideyuki [Faculty of Science and Technology, Tokyo University of Science, Yamazaki 2641, Noda, Chiba 278-8510 (Japan)

    2014-05-02

    We perform numerical experiments to investigate the influence of inelastic neutrino reactions with light nuclei on the standing accretion shock instability. The time evolutions of shock waves are calculated with a simple light-bulb approximation for the neutrino transport and a multi-nuclei equation of state. The neutrino absorptions and inelastic interactions with deuterons, tritons, helions and alpha particles are taken into account in the hydrodynamical simulations in addition to the ordinary charged-current interactions with nucleons. Axial symmetry is assumed but no equatorial symmetry is imposed. We show that the heating rates of deuterons reach as high as ? 10% of those of nucleons around the bottom of the gain region. On the other hands, alpha particles heat the matter near the shock wave, which is important when the shock wave expands and density and temperature of matter become low. It is also found that the models with heating by light nuclei have different evolutions from those without it in non-linear evolution phase. The matter in the gain region has various densities and temperatures and there appear regions that are locally rich in deuterons and alpha particles. These results indicate that the inelastic reactions of light nuclei, especially deuterons, should be incorporated in the simulations of core-collapse supernovae.

  4. Oblique shock breakout in supernovae and gamma-ray bursts. II. Numerical solutions for non-relativistic pattern speeds

    SciTech Connect (OSTI)

    Salbi, Pegah; Matzner, Christopher D.; Ro, Stephen [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Levin, Yuri, E-mail: salbi@astro.utoronto.ca [Monash Center for Astrophysics, Monash University, Clayton, VIC 3800 (Australia)

    2014-07-20

    Non-spherical explosions develop non-radial flows as the pattern of shock emergence progresses across the stellar surface. In supernovae, these flows can limit ejecta speeds, stifle shock breakout emission, and cause collisions outside the star. Similar phenomena occur in stellar and planetary collisions, tidal disruption events, accretion-induced collapses, and propagating detonations. We present two-dimensional, nested-grid Athena simulations of non-radial shock emergence in a frame comoving with the breakout pattern, focusing on the adiabatic, non-relativistic limit in a plane stratified envelope. We set boundary conditions using a known self-similar solution and explore the role of box size and resolution on the result. The shock front curves toward the stellar surface, and exhibits a kink from which weak discontinuities originate. Flow around the point of shock emergence is neither perfectly steady nor self-similar. Waves and vortices, which are not predominantly due to grid effects, emanate from this region. The post-shock flow is deflected along the stellar surface and its pressure disturbs the stellar atmosphere upstream of the emerging shock. We use the numerical results and their analytical limits to predict the effects of radiation transfer and gravity, which are not included in our simulations.

  5. Gamma-Ray Observations of the Supernova Remnant RX J0852.0-4622 with the Fermi LAT

    SciTech Connect (OSTI)

    Tanaka, T.; Allafort, A.; Ballet, J.; Funk, S.; Giordano, F.; Hewitt, J.; Lemoine-Goumard, M.; Tajima, H.; Tibolla, O.; Uchiyama, Y.; /Stanford U., HEPL /KIPAC, Menlo Park

    2011-12-13

    We report on gamma-ray observations of the supernova remnant (SNR) RX J0852.0-4622 with the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope. In the Fermi LAT data, we find a spatially extended source at the location of the SNR. The extension is consistent with the SNR size seen in other wavelengths such as X-rays and TeV gamma rays, leading to the identification of the gamma-ray source with the SNR. The spectrum is well described as a power law with a photon index of {Lambda} = 1.85 {+-} 0.06 (stat){sub -0.19}{sup +0.18} (sys), which smoothly connects to the H.E.S.S. spectrum in the TeV energy band. We discuss the gamma-ray emission mechanism based on multiwavelength data. The broadband data can be fit well by a model in which the gamma rays are of hadronic origin. We also consider a scenario with inverse Compton scattering of electrons as the emission mechanism of the gamma rays. Although the leptonic model predicts a harder spectrum in the Fermi LAT energy range, the model can fit the data considering the statistical and systematic errors.

  6. Three dimensional core-collapse supernova simulated using a 15 M progenitor

    SciTech Connect (OSTI)

    Lentz, Eric J.; Bruenn, Stephen W.; Hix, W. Raphael; Mezzacappa, Anthony; Messer, O. E. Bronson; Endeve, Eirik; Blondin, John M.; Harris, J. Austin; Marronetti, Pedro; Yakunin, Konstantin N.

    2015-07-10

    We have performed ab initio neutrino radiation hydrodynamics simulations in three and two spatial dimensions (3D and 2D) of core-collapse supernovae from the same 15 M⊙ progenitor through 440 ms after core bounce. Both 3D and 2D models achieve explosions; however, the onset of explosion (shock revival) is delayed by ~100 ms in 3D relative to the 2D counterpart and the growth of the diagnostic explosion energy is slower. This is consistent with previously reported 3D simulations utilizing iron-core progenitors with dense mantles. In the ~100 ms before the onset of explosion, diagnostics of neutrino heating and turbulent kinetic energy favor earlier explosion in 2D. During the delay, the angular scale of convective plumes reaching the shock surface grows and explosion in 3D is ultimately lead by a single, large-angle plume, giving the expanding shock a directional orientation not dissimilar from those imposed by axial symmetry in 2D simulations. Finally, we posit that shock revival and explosion in the 3D simulation may be delayed until sufficiently large plumes form, whereas such plumes form more rapidly in 2D, permitting earlier explosions.

  7. CHEMICAL EVOLUTION OF THE LARGE MAGELLANIC CLOUD

    SciTech Connect (OSTI)

    Bekki, Kenji [ICRAR, M468, University of Western Australia, 35 Stirling Highway, Crawley Western Australia 6009 (Australia); Tsujimoto, Takuji [National Astronomical Observatory of Japan, Mitaka-shi, Tokyo 181-8588 (Japan)

    2012-12-20

    We adopt a new chemical evolution model for the Large Magellanic Cloud (LMC) and thereby investigate its past star formation and chemical enrichment histories. The delay time distribution of Type Ia supernovae recently revealed by Type Ia supernova surveys is incorporated self-consistently into the new model. The principle results are summarized as follows. The present gas mass fraction and stellar metallicity as well as the higher [Ba/Fe] in metal-poor stars at [Fe/H] < -1.5 can be more self-consistently explained by models with steeper initial mass functions. The observed higher [Mg/Fe] ({>=}0.3) at [Fe/H] {approx} -0.6 and higher [Ba/Fe] (>0.5) at [Fe/H] {approx} -0.3 could be due to significantly enhanced star formation about 2 Gyr ago. The observed overall [Ca/Fe]-[Fe/H] relation and remarkably low [Ca/Fe] (< - 0.2) at [Fe/H] > -0.6 are consistent with models with short-delay supernova Ia and with the more efficient loss of Ca possibly caused by an explosion mechanism of Type II supernovae. Although the metallicity distribution functions do not show double peaks in the models with a starburst about 2 Gyr ago, they show characteristic double peaks in the models with double starbursts {approx}200 Myr and {approx}2 Gyr ago. The observed apparent dip of [Fe/H] around {approx}1.5 Gyr ago in the age-metallicity relation can be reproduced by models in which a large amount ({approx}10{sup 9} M{sub Sun }) of metal-poor ([Fe/H] < -1) gas can be accreted onto the LMC.

  8. A classical and a relativistic law of motion for spherical supernovae

    SciTech Connect (OSTI)

    Zaninetti, Lorenzo

    2014-11-01

    In this paper we derive some first order differential equations which model the classical and the relativistic thin layer approximations. The circumstellar medium is assumed to follow a density profile of the Plummer type, the Lane-Emden (n = 5) type, or a power law. The first order differential equations are solved analytically, numerically, by a series expansion, or by recursion. The initial conditions are chosen in order to model the temporal evolution of SN 1993J over 10 yr and a smaller chi-squared is obtained for the Plummer case with η = 6. The stellar mass ejected by the SN progenitor prior to the explosion, expressed in solar mass, is identified with the total mass associated with the selected density profile and varies from 0.217 to 0.402 when the central number density is 10{sup 7} particles per cubic centimeter. The FWHM of the three density profiles, which can be identified with the size of the pre-SN 1993J envelope, varies from 0.0071 pc to 0.0092 pc.

  9. Code dependencies of pre-supernova evolution and nucleosynthesis in massive stars: evolution to the end of core helium burning

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jones, S.; Hirschi, R.; Pignatari, M.; Heger, A.; Georgy, C.; Nishimura, N.; Fryer, C.; Herwig, F.

    2015-01-15

    We present a comparison of 15M⊙ , 20M⊙ and 25M⊙ stellar models from three different codes|GENEC, KEPLER and MESA|and their nucleosynthetic yields. The models are calculated from the main sequence up to the pre-supernova (pre-SN) stage and do not include rotation. The GENEC and KEPLER models hold physics assumptions that are characteristic of the two codes. The MESA code is generally more flexible; overshooting of the convective core during the hydrogen and helium burning phases in MESA is chosen such that the CO core masses are consistent with those in the GENEC models. Full nucleosynthesis calculations are performed for allmore » models using the NuGrid post-processing tool MPPNP and the key energy-generating nuclear reaction rates are the same for all codes. We are thus able to highlight the key diferences between the models that are caused by the contrasting physics assumptions and numerical implementations of the three codes. A reasonable agreement is found between the surface abundances predicted by the models computed using the different codes, with GENEC exhibiting the strongest enrichment of H-burning products and KEPLER exhibiting the weakest. There are large variations in both the structure and composition of the models—the 15M⊙ and 20M⊙ in particular—at the pre-SN stage from code to code caused primarily by convective shell merging during the advanced stages. For example the C-shell abundances of O, Ne and Mg predicted by the three codes span one order of magnitude in the 15M⊙ models. For the alpha elements between Si and Fe the differences are even larger. The s-process abundances in the C shell are modified by the merging of convective shells; the modification is strongest in the 15M⊙ model in which the C-shell material is exposed to O-burning temperatures and the γ -process is activated. The variation in the s-process abundances across the codes is smallest in the 25M⊙ models, where it is comparable to the impact of nuclear

  10. The development of explosions in axisymmetric ab initio core-collapse supernova simulations of 12–25 M⊙ stars

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bruenn, Stephen W.; Lentz, Eric J.; Hix, William Raphael; Mezzacappa, Anthony; Harris, James Austin; Messer, O. E. Bronson; Endeve, Eirik; Blondin, John M.; Chertkow, Merek Austin; Lingerfelt, Eric J.; et al

    2016-02-16

    We present four ab initio axisymmetric core-collapse supernova simulations initiated from 12, 15, 20, and 25 M⊙ zero-age main sequence progenitors. All of the simulations yield explosions and have been evolved for at least 1.2 s after core bounce and 1 s after material first becomes unbound. These simulations were computed with our Chimera code employing RbR spectral neutrino transport, special and general relativistic transport effects, and state-of-the-art neutrino interactions. Continuing the evolution beyond 1 s after core bounce allows the explosions to develop more fully and the processes involved in powering the explosions to become more clearly evident. Wemore » compute explosion energy estimates, including the negative gravitational binding energy of the stellar envelope outside the expanding shock, of 0.34, 0.88, 0.38, and 0.70 Bethe (B ≡ 1051 erg) and increasing at 0.03, 0.15, 0.19, and 0.52 BS–1, respectively, for the 12, 15, 20, and 25 M⊙ models at the endpoint of this report. We examine the growth of the explosion energy in our models through detailed analyses of the energy sources and flows. We discuss how the explosion energies may be subject to stochastic variations as exemplfied by the effect of the explosion geometry of the 20 M⊙ model in reducing its explosion energy. We compute the proto-neutron star masses and kick velocities. In conclusion, we compare our results for the explosion energies and ejected 56Ni masses against some observational standards despite the large error bars in both models and observations.« less

  11. AXISYMMETRIC AB INITIO CORE-COLLAPSE SUPERNOVA SIMULATIONS OF 12-25 M{sub Sun} STARS

    SciTech Connect (OSTI)

    Bruenn, Stephen W.; Yakunin, Konstantin N.; Mezzacappa, Anthony; Hix, W. Raphael; Lingerfelt, Eric J.; Lentz, Eric J.; Messer, O. E. Bronson; Blondin, John M.; Endeve, Eirik; Marronetti, Pedro

    2013-04-10

    We present an overview of four ab initio axisymmetric core-collapse supernova simulations employing detailed spectral neutrino transport computed with our CHIMERA code and initiated from Woosley and Heger progenitors of mass 12, 15, 20, and 25 M{sub Sun }. All four models exhibit shock revival over {approx}200 ms (leading to the possibility of explosion), driven by neutrino energy deposition. Hydrodynamic instabilities that impart substantial asymmetries to the shock aid these revivals, with convection appearing first in the 12 M{sub Sun} model and the standing accretion shock instability appearing first in the 25 M{sub Sun} model. Three of the models have developed pronounced prolate morphologies (the 20 M{sub Sun} model has remained approximately spherical). By 500 ms after bounce the mean shock radii in all four models exceed 3000 km and the diagnostic explosion energies are 0.33, 0.66, 0.65, and 0.70 Bethe (B = 10{sup 51} erg) for the 12, 15, 20, and 25 M{sub Sun} models, respectively, and are increasing. The three least massive of our models are already sufficiently energetic to completely unbind the envelopes of their progenitors (i.e., to explode), as evidenced by our best estimate of their explosion energies, which first become positive at 320, 380, and 440 ms after bounce. By 850 ms the 12 M{sub Sun} diagnostic explosion energy has saturated at 0.38 B, and our estimate for the final kinetic energy of the ejecta is {approx}0.3 B, which is comparable to observations for lower mass progenitors.

  12. An expanded HST/WFC3 survey of M83: Project overview and targeted supernova remnant search

    SciTech Connect (OSTI)

    Blair, William P.; Kuntz, K. D.; Chandar, Rupali; Dopita, Michael A.; Ghavamian, Parviz; Hammer, Derek; Long, Knox S.; Whitmore, Bradley C.; Soria, Roberto; Frank Winkler, P. E-mail: kuntz@pha.jhu.edu E-mail: Michael.Dopita@anu.edu.au E-mail: long@stsci.edu E-mail: whitmore@stsci.edu E-mail: winkler@middlebury.edu

    2014-06-10

    We present an optical/NIR imaging survey of the face-on spiral galaxy M83, using data from the Hubble Space Telescope Wide Field Camera 3 (WFC3). Seven fields are used to cover a large fraction of the inner disk, with observations in nine broadband and narrowband filters. In conjunction with a deep Chandra survey and other new radio and optical ground-based work, these data enable a broad range of science projects to be pursued. We provide an overview of the WFC3 data and processing and then delve into one topic, the population of young supernova remnants (SNRs). We used a search method targeted toward soft X-ray sources to identify 26 new SNRs. Many compact emission nebulae detected in [Fe II] 1.644 μm align with known remnants and this diagnostic has also been used to identify many new remnants, some of which are hard to find with optical images. We include 37 previously identified SNRs that the data reveal to be <0.''5 in angular size and thus are difficult to characterize from ground-based data. The emission line ratios seen in most of these objects are consistent with shocks in dense interstellar material rather than showing evidence of ejecta. We suggest that the overall high elemental abundances in combination with high interstellar medium pressures in M83 are responsible for this result. Future papers will expand on different aspects of the these data including a more comprehensive analysis of the overall SNR population.

  13. Magnetically dominated jets inside collapsing stars as a model for gamma-ray bursts and supernova explosions

    SciTech Connect (OSTI)

    Uzdensky, Dmitri A.; MacFadyen, Andrew I.

    2007-05-15

    It has been suggested that magnetic fields play a dynamically important role in core-collapse explosions of massive stars. In particular, they may be important in the collapsar scenario for gamma-ray bursts (GRB), where the central engine is a hyperaccreting black hole or a millisecond magnetar. The present paper is focused on the magnetar scenario, with a specific emphasis on the interaction of the magnetar magnetosphere with the infalling stellar envelope. First, the 'pulsar-in-a-cavity' problem is introduced as a paradigm for a magnetar inside a collapsing star. The basic setup of this fundamental plasma-physics problem is described, outlining its main features, and simple estimates are derived for the evolution of the magnetic field. In the context of a collapsing star, it is proposed that, at first, the ram pressure of the infalling plasma acts to confine the magnetosphere, enabling a gradual buildup of the magnetic pressure. At some point, the growing magnetic pressure overtakes the (decreasing) ram pressure of the gas, resulting in a magnetically driven explosion. The explosion should be highly anisotropic, as the hoop stress of the toroidal field, confined by the surrounding stellar matter, collimates the magnetically dominated outflow into two beamed magnetic-tower jets. This creates a clean narrow channel for the escape of energy from the central engine through the star, as required for GRBs. In addition, the delayed onset of the collimated-explosion phase can explain the production of large quantities of nickel-56, as suggested by the GRB-supernova connection. Finally, the prospects for numerical simulations of this scenario are discussed.

  14. A multi-wavelength investigation of the radio-loud supernova PTF11qcj and its circumstellar environment

    SciTech Connect (OSTI)

    Corsi, A.; Ofek, E. O.; Gal-Yam, A.; Xu, D.; Frail, D. A.; Kulkarni, S. R.; Horesh, A.; Carpenter, J.; Arcavi, I.; Cao, Y.; Mooley, K.; Sesar, B.; Fox, D. B.; Kasliwal, M. M.; Sullivan, M.; Maguire, K.; Pan, Y.-C.; Cenko, S. B.; Sternberg, A.; Bersier, D.; and others

    2014-02-10

    We present the discovery, classification, and extensive panchromatic (from radio to X-ray) follow-up observations of PTF11qcj, a supernova (SN) discovered by the Palomar Transient Factory (PTF). Our observations with the Karl G. Jansky Very Large Array show that this event is radio-loud: PTF11qcj reached a radio peak luminosity comparable to that of the famous gamma-ray-burst-associated SN 1998bw (L {sub 5} {sub GHz} ? 10{sup 29} erg s{sup 1} Hz{sup 1}). PTF11qcj is also detected in X-rays with the Chandra Observatory, and in the infrared band with Spitzer. Our multi-wavelength analysis probes the SN interaction with circumstellar material. The radio observations suggest a progenitor mass-loss rate of ?10{sup 4} M {sub ?} yr{sup 1} (v{sub w} /1000 km s{sup 1}), and a velocity of ?0.3-0.5 c for the fastest moving ejecta (at ?10 days after explosion). However, these estimates are derived assuming the simplest model of SN ejecta interacting with a smooth circumstellar wind, and do not account for possible inhomogeneities in the medium and asphericity of the explosion. The radio data show deviations from such a simple model, as well as a late-time re-brightening. The X-ray flux from PTF11qcj is compatible with the high-frequency extrapolation of the radio synchrotron emission (within the large uncertainties). A light echo from pre-existing dust is in agreement with our infrared data. Our pre-explosion data from the PTF suggest that a precursor eruption of absolute magnitude M{sub r} ? 13 mag may have occurred ?2.5 yr prior to the SN explosion. Overall, PTF11qcj fits the expectations from the explosion of a Wolf-Rayet star. Precursor eruptions may be a feature characterizing the final pre-explosion evolution of such stars.

  15. Hydrogen-poor superluminous supernovae and long-duration gamma-ray bursts have similar host galaxies

    SciTech Connect (OSTI)

    Lunnan, R.; Chornock, R.; Berger, E.; Laskar, T.; Fong, W.; Sanders, N. E.; Challis, P. M.; Drout, M. R.; Foley, R. J.; Kirshner, R. P.; Leibler, C.; Marion, G. H.; Milisavljevic, D.; Narayan, G.; Rest, A.; Huber, M. E.; McCrum, M.; Smartt, S. J.; Smith, K. W.; Scolnic, D.; and others

    2014-06-01

    We present optical spectroscopy and optical/near-IR photometry of 31 host galaxies of hydrogen-poor superluminous supernovae (SLSNe), including 15 events from the Pan-STARRS1 Medium Deep Survey. Our sample spans the redshift range 0.1 ≲ z ≲ 1.6, and is the first comprehensive host galaxy study of this specific subclass of cosmic explosions. Combining the multi-band photometry and emission-line measurements, we determine the luminosities, stellar masses, star formation rates, and metallicities. We find that, as a whole, the hosts of SLSNe are a low-luminosity ((M{sub B} ) ≈ –17.3 mag), low stellar mass ((M {sub *}) ≈ 2 × 10{sup 8} M {sub ☉}) population, with a high median specific star formation rate ((sSFR) ≈ 2 Gyr{sup –1}). The median metallicity of our spectroscopic sample is low, 12 + log (O/H) ≈ 8.35 ≈ 0.45 Z {sub ☉}, although at least one host galaxy has solar metallicity. The host galaxies of H-poor SLSNe are statistically distinct from the hosts of GOODS core-collapse SNe (which cover a similar redshift range), but resemble the host galaxies of long-duration gamma-ray bursts (LGRBs) in terms of stellar mass, SFR, sSFR, and metallicity. This result indicates that the environmental causes leading to massive stars forming either SLSNe or LGRBs are similar, and in particular that SLSNe are more effectively formed in low metallicity environments. We speculate that the key ingredient is large core angular momentum, leading to a rapidly spinning magnetar in SLSNe and an accreting black hole in LGRBs.

  16. A new multi-dimensional general relativistic neutrino hydrodynamics code for core-collapse supernovae. IV. The neutrino signal

    SciTech Connect (OSTI)

    Mller, Bernhard [Monash Center for Astrophysics, School of Mathematical Sciences, Building 28, Monash University, Victoria 3800 (Australia); Janka, Hans-Thomas, E-mail: bernhard.mueller@monash.edu, E-mail: bjmuellr@mpa-garching.mpg.de, E-mail: thj@mpa-garching.mpg.de [Max-Planck-Institut fr Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany)

    2014-06-10

    Considering six general relativistic, two-dimensional (2D) supernova (SN) explosion models of progenitor stars between 8.1 and 27 M {sub ?}, we systematically analyze the properties of the neutrino emission from core collapse and bounce to the post-explosion phase. The models were computed with the VERTEX-COCONUT code, using three-flavor, energy-dependent neutrino transport in the ray-by-ray-plus approximation. Our results confirm the close similarity of the mean energies, (E), of ?-bar {sub e} and heavy-lepton neutrinos and even their crossing during the accretion phase for stars with M ? 10 M {sub ?} as observed in previous 1D and 2D simulations with state-of-the-art neutrino transport. We establish a roughly linear scaling of ?E{sub ?-bar{sub e}}? with the proto-neutron star (PNS) mass, which holds in time as well as for different progenitors. Convection inside the PNS affects the neutrino emission on the 10%-20% level, and accretion continuing beyond the onset of the explosion prevents the abrupt drop of the neutrino luminosities seen in artificially exploded 1D models. We demonstrate that a wavelet-based time-frequency analysis of SN neutrino signals in IceCube will offer sensitive diagnostics for the SN core dynamics up to at least ?10 kpc distance. Strong, narrow-band signal modulations indicate quasi-periodic shock sloshing motions due to the standing accretion shock instability (SASI), and the frequency evolution of such 'SASI neutrino chirps' reveals shock expansion or contraction. The onset of the explosion is accompanied by a shift of the modulation frequency below 40-50 Hz, and post-explosion, episodic accretion downflows will be signaled by activity intervals stretching over an extended frequency range in the wavelet spectrogram.

  17. A mid-life crisis? Sudden changes in radio and X-ray emission from supernova 1970G

    SciTech Connect (OSTI)

    Dittmann, J. A.; Soderberg, A. M.; Margutti, R.; Milisavljevic, D. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Chomiuk, L. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Goss, W. M. [National Radio Astronomy Observatory, Domenici Science Operations Center, Socorro, NM 87801 (United States); Chevalier, R. A., E-mail: jdittmann@cfa.harvard.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

    2014-06-10

    Supernovae (SNe) provide a backdrop from which we can probe the end state of stellar evolution in the final years before the progenitor star explodes. As the shock from the SN expands, the timespan of mass-loss history we are able to probe also extends, providing insight to rapid timescale processes that govern the end state of massive stars. While SNe transition into remnants on timescales of decades to centuries, observations of this phase are currently limited. Here, we present observations of SN 1970G, serendipitously observed during the monitoring campaign of SN 2011fe, which shares the same host galaxy. Utilizing the new Jansky Very Large Array (VLA) upgrade and a deep X-ray exposure taken by Chandra, we are able to recover this middle-aged SN and distinctly resolve it from the H II cloud with which it is associated. We find that the flux density of SN 1970G has changed significantly since it was last observedthe X-ray luminosity has increased by a factor of ?3, while we observe a significantly lower radio flux of only 27.5 ?Jy at 6.75 GHz, a level only detectable through the upgrades now in operation at the Jansky VLA. These changes suggest that SN 1970G has entered a new stage of evolution toward an SN remnant, and we may be detecting the turn-on of the pulsar wind nebula. Deep radio observations of additional middle-aged SNe with the improved radio facilities will provide a statistical census of the delicate transition period between SN and remnant.

  18. Hubble space telescope observations of the afterglow, supernova, and host galaxy associated with the extremely bright GRB 130427A

    SciTech Connect (OSTI)

    Levan, A. J. [Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom); Tanvir, N. R.; Wiersema, K. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH (United Kingdom); Fruchter, A. S.; Hounsell, R. A.; Graham, J. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Hjorth, J.; Fynbo, J. P. U. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Pian, E. [INAF, Trieste Astronomical Observatory, via G.B. Tiepolo 11, I-34143 Trieste (Italy); Mazzali, P. [Astrophysics Research Institute, Liverpool John Moores University, IC2 Liverpool Science Park 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Perley, D. A. [Department of Astronomy, California Institute of Technology, MC 249-17, 1200 East California Blvd., Pasadena, CA 91125 (United States); Cano, Z. [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, 107 Reykjavik (Iceland); Cenko, S. B. [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Kouveliotou, C. [Science and Technology Office, ZP12, NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States); Pe'er, A. [Department of Physics, University College Cork, Cork (Ireland); Misra, K., E-mail: a.j.levan@warwick.ac.uk [Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital-263 002 (India)

    2014-09-10

    We present Hubble Space Telescope (HST) observations of the exceptionally bright and luminous Swift gamma-ray burst (GRB), GRB 130427A. At z = 0.34, this burst affords an excellent opportunity to study the supernova (SN) and host galaxy associated with an intrinsically extremely luminous burst (E {sub iso} > 10{sup 54} erg): more luminous than any previous GRB with a spectroscopically associated SN. We use the combination of the image quality, UV capability, and invariant point-spread function of HST to provide the best possible separation of the afterglow, host, and SN contributions to the observed light ?17 rest-frame days after the burst, utilizing a host subtraction spectrum obtained one year later. Advanced Camera for Surveys grism observations show that the associated SN, SN 2013cq, has an overall spectral shape and luminosity similar to SN 1998bw (with a photospheric velocity, v {sub ph} ? 15, 000 km s{sup 1}). The positions of the bluer features are better matched by the higher velocity SN 2010bh (v {sub ph} ? 30, 000 km s{sup 1}), but this SN is significantly fainter and fails to reproduce the overall spectral shape, perhaps indicative of velocity structure in the ejecta. We find that the burst originated ?4 kpc from the nucleus of a moderately star forming (1 M {sub ?} yr{sup 1}), possibly interacting disk galaxy. The absolute magnitude, physical size, and morphology of this galaxy, as well as the location of the GRB within it, are also strikingly similar to those of GRB 980425/SN 1998bw. The similarity of the SNe and environment from both the most luminous and least luminous GRBs suggests that broadly similar progenitor stars can create GRBs across six orders of magnitude in isotropic energy.

  19. Pan-STARRS1 DISCOVERY OF TWO ULTRALUMINOUS SUPERNOVAE AT z Almost-Equal-To 0.9

    SciTech Connect (OSTI)

    Chomiuk, L.; Chornock, R.; Soderberg, A. M.; Berger, E.; Foley, R. J.; Kirshner, R. P.; Czekala, I.; Chevalier, R. A.; Huber, M. E.; Gezari, S.; Riess, A.; Rodney, S. A.; Narayan, G.; Stubbs, C. W.; Rest, A.; Smartt, S. J.; Tonry, J. L.; Burgett, W. S.; Chambers, K. C.; Wood-Vasey, W. M.; and others

    2011-12-20

    We present the discovery of two ultraluminous supernovae (SNe) at z Almost-Equal-To 0.9 with the Pan-STARRS1 Medium Deep Survey. These SNe, PS1-10ky and PS1-10awh, are among the most luminous SNe ever discovered, comparable to the unusual transients SN 2005ap and SCP 06F6. Like SN 2005ap and SCP 06F6, they show characteristic high luminosities (M{sub bol} Almost-Equal-To -22.5 mag), blue spectra with a few broad absorption lines, and no evidence for H or He. We have constructed a full multi-color light curve sensitive to the peak of the spectral energy distribution in the rest-frame ultraviolet, and we have obtained time series spectroscopy for these SNe. Given the similarities between the SNe, we combine their light curves to estimate a total radiated energy over the course of explosion of (0.9-1.4) Multiplication-Sign 10{sup 51} erg. We find photospheric velocities of 12,000-19,000 km s{sup -1} with no evidence for deceleration measured across {approx}3 rest-frame weeks around light curve peak, consistent with the expansion of an optically thick massive shell of material. We show that, consistent with findings for other ultraluminous SNe in this class, radioactive decay is not sufficient to power PS1-10ky, and we discuss two plausible origins for these events: the initial spin-down of a newborn magnetar in a core-collapse SN, or SN shock breakout from the dense circumstellar wind surrounding a Wolf-Rayet star.

  20. THREE-DIMENSIONAL SIMULATIONS OF THE THERMAL X-RAY EMISSION FROM YOUNG SUPERNOVA REMNANTS INCLUDING EFFICIENT PARTICLE ACCELERATION

    SciTech Connect (OSTI)

    Ferrand, Gilles; Safi-Harb, Samar; Decourchelle, Anne E-mail: samar@physics.umanitoba.ca

    2012-11-20

    Supernova remnants (SNRs) are believed to be the major contributors to Galactic cosmic rays. The detection of non-thermal emission from SNRs demonstrates the presence of energetic particles, but direct signatures of protons and other ions remain elusive. If these particles receive a sizeable fraction of the explosion energy, the morphological and spectral evolution of the SNR must be modified. To assess this, we run three-dimensional hydrodynamic simulations of a remnant coupled with a nonlinear acceleration model. We obtain the time-dependent evolution of the shocked structure, impacted by the Rayleigh-Taylor hydrodynamic instabilities at the contact discontinuity and by the back-reaction of particles at the forward shock. We then compute the progressive temperature equilibration and non-equilibrium ionization state of the plasma, and its thermal emission in each cell. This allows us to produce the first realistic synthetic maps of the projected X-ray emission from the SNR. Plasma conditions (temperature and ionization age) can vary widely over the projected surface of the SNR, especially between the ejecta and the ambient medium owing to their different composition. This demonstrates the need for spatially resolved spectroscopy. We find that the integrated emission is reduced with particle back-reaction, with the effect being more significant for the highest photon energies. Therefore, different energy bands, corresponding to different emitting elements, probe different levels of the impact of particle acceleration. Our work provides a framework for the interpretation of SNR observations with current X-ray missions (Chandra, XMM-Newton, and Suzaku) and with upcoming X-ray missions (such as Astro-H).

  1. TITLE AUTHORS SUBJECT SUBJECT RELATED DESCRIPTION PUBLISHER AVAILABILI...

    Office of Scientific and Technical Information (OSTI)

    High Statistics Study of Nearby Type a Supernovae QUEST Camera Short Term Maintenance Final Technical Report Baltay Charles ASTRONOMY AND ASTROPHYSICS Study of Type a Supernovae...

  2. Agreement Type Union

    National Nuclear Security Administration (NNSA)

    Type Union Local #/Name Number of Employees Project Labor Agreement International Association of Heat and Frost Insulators and Allied Workers 135 2 International Brothehood of Boilermakers, Iron Ship Builders, Blacksmith Forgers and Helpers 92 0 International Union of Bricklayers & Allied Craftsmen 13 0 Regional Council of Carpenters 1780 & 1977 13 Operative Plasterers and Cement Mason International Association Operative Plasterers and Cement Mason International Association 1

  3. TYPE OF OPERATION

    Office of Legacy Management (LM)

    ----------------- 0 Research & Development .a Production scale testing 0 Pilat Scale 0 Bench Scale Process 0 Thearetical Studies Cl Sample 84 Analysis 0 Production *i DiaposalKitorage Cl Facility Tybe q Government Sponsored Facility Other R.L- 6:e 14 1 1 ---------- --------- I I I TYPE OF CONTRACT ~-__-----------_ fl Prime *I 0 Subcantractbr Other infuriation (i.e., L.t + fixed fee, kit price, 0 Purchase Order time k mat*iik, gtc) /I -~---------'-t-----------~- ----------II----------------

  4. Energy.gov Page Types

    Broader source: Energy.gov [DOE]

    Learn about the standard page types available in the Energy.gov Drupal content management system. For information about other available page types, or to request a new kind of page type, contact...

  5. Distance-redshift relations in an anisotropic cosmological model

    SciTech Connect (OSTI)

    Menezes, R. S. Jr.; Pigozzo, C.; Carneiro, S. E-mail: cpigozzo@ufba.br

    2013-03-01

    In this paper we study an anisotropic model generated from a particular Bianchi type-III metric, which is a generalization of Gdel's metric and an exact solution of Einstein's field equations. We analyse type Ia supernova data, namely the SDSS sample calibrated with the MLCS2k2 fitter, and we verify in which ranges of distances and redshifts the anisotropy could be observed. We also consider, in a joint analysis, the position of the first peak in the CMB anisotropy spectrum, as well as current observational constraints on the Hubble constant. We conclude that a small anisotropy is permitted by the data, and that more accurate measurements of supernova distances above z = 2 might indicate the existence of such anisotropy in the universe.

  6. HOT GAS HALOS IN EARLY-TYPE FIELD GALAXIES

    SciTech Connect (OSTI)

    Mulchaey, John S.; Jeltema, Tesla E. E-mail: tesla@ucolick.or

    2010-05-20

    We use Chandra and XMM-Newton to study the hot gas content in a sample of field early-type galaxies. We find that the L {sub X}-L {sub K} relationship is steeper for field galaxies than for comparable galaxies in groups and clusters. The low hot gas content of field galaxies with L {sub K} {approx_lt} L {sub *} suggests that internal processes such as supernovae-driven winds or active galactic nucleus feedback expel hot gas from low-mass galaxies. Such mechanisms may be less effective in groups and clusters where the presence of an intragroup or intracluster medium can confine outflowing material. In addition, galaxies in groups and clusters may be able to accrete gas from the ambient medium. While there is a population of L {sub K} {approx_lt} L {sub *} galaxies in groups and clusters that retain hot gas halos, some galaxies in these rich environments, including brighter galaxies, are largely devoid of hot gas. In these cases, the hot gas halos have likely been removed via ram pressure stripping. This suggests a very complex interplay between the intragroup/intracluster medium and hot gas halos of galaxies in rich environments, with the ambient medium helping to confine or even enhance the halos in some cases and acting to remove gas in others. In contrast, the hot gas content of more isolated galaxies is largely a function of the mass of the galaxy, with more massive galaxies able to maintain their halos, while in lower mass systems the hot gas escapes in outflowing winds.

  7. Light-element nucleosynthesis in a molecular cloud interacting with a supernova remnant and the origin of beryllium-10 in the protosolar nebula

    SciTech Connect (OSTI)

    Tatischeff, Vincent; Duprat, Jean [Centre de Sciences Nuclaires et de Sciences de la Matire, IN2P3-CNRS and Univ Paris-Sud, F-91405 Orsay Cedex (France); De Srville, Nicolas, E-mail: Vincent.Tatischeff@csnsm.in2p3.fr [Institut de Physique Nuclaire d'Orsay, IN2P3-CNRS and Univ Paris-Sud, F-91405 Orsay Cedex (France)

    2014-12-01

    The presence of short-lived radionuclides (t {sub 1/2} < 10 Myr) in the early solar system provides important information about the astrophysical environment in which the solar system formed. The discovery of now extinct {sup 10}Be (t {sub 1/2} = 1.4 Myr) in calcium-aluminum-rich inclusions (CAIs) with Fractionation and Unidentified Nuclear isotope anomalies (FUN-CAIs) suggests that a baseline concentration of {sup 10}Be in the early solar system was inherited from the protosolar molecular cloud. In this paper, we investigate various astrophysical contexts for the nonthermal nucleosynthesis of {sup 10}Be by cosmic-ray-induced reactions. We first show that the {sup 10}Be recorded in FUN-CAIs cannot have been produced in situ by irradiation of the FUN-CAIs themselves. We then show that trapping of Galactic cosmic rays (GCRs) in the collapsing presolar cloud core induced a negligible {sup 10}Be contamination of the protosolar nebula, the inferred {sup 10}Be/{sup 9}Be ratio being at least 40 times lower than that recorded in FUN-CAIs ({sup 10}Be/{sup 9}Be ? 3 10{sup 4}). Irradiation of the presolar molecular cloud by background GCRs produced a steady-state {sup 10}Be/{sup 9}Be ratio ? 1.3 10{sup 4} at the time of the solar system formation, which suggests that the presolar cloud was irradiated by an additional source of CRs. Considering a detailed model for CR acceleration in a supernova remnant (SNR), we find that the {sup 10}Be abundance recorded in FUN-CAIs can be explained within two alternative scenarios: (1) the irradiation of a giant molecular cloud by CRs produced by ? 50 supernovae exploding in a superbubble of hot gas generated by a large star cluster of at least 20,000 members, and (2) the irradiation of the presolar molecular cloud by freshly accelerated CRs escaped from an isolated SNR at the end of the Sedov-Taylor phase. In the second picture, the SNR resulted from the explosion of a massive star that ran away from its parent OB association

  8. THE MID-INFRARED AND OPTICAL DECAY OF SN 2011fe

    SciTech Connect (OSTI)

    McClelland, Colin M.; Garnavich, Peter M.; Milne, Peter A.; Shappee, Benjamin J.; Pogge, Richard W.

    2013-04-20

    We measure the decay rate of the mid-IR luminosity from Type Ia supernova 2011fe between six months and one year after explosion using Spitzer/IRAC observations. The fading in the 3.6 {mu}m channel is 1.48 {+-} 0.02 mag/100{sup d}, which is similar to that seen in blue optical bands. The supernova brightness fades at 0.78 {+-} 0.02 mag/100{sup d} in the 4.5 {mu}m channel which is close to that observed in the near-IR. We argue that the difference is a result of doubly ionized iron-peak elements dominating the bluer IRAC band while singly ionized species are controlling the longer wavelength channel. To test this, we use Large Binocular Telescope spectra taken during the same phases to show that doubly ionized emission lines do fade more slowly than their singly ionized cousins. We also find that [Co III] emission fades at more than twice the radioactive decay rate due to the combination of decreasing excitation in the nebula, recombination and cobalt decaying to iron. The nebular emission velocities of [Fe III] and [Co III] lines show a smaller blueshift than emission from singly ionized atoms. The Si II velocity gradient near maximum light combined with our nebular velocity measurements suggest SN 2011fe was a typical member of the ''low velocity gradient'' class of Type Ia. Analyzing IRAC photometry from other supernovae we find that mid-IR color of Type Ia events is correlated with the early light curve width and can be used as an indicator of the radioactive nickel yield.

  9. Supernova Hunting with Supercomputers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Transient Factory (iPTF), which uses machine-learning algorithms running on NERSC ... Follow up observations with NASA's Swift Space Telescope showed ultraviolet signals ...

  10. Core-Collapse Supernovae

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Nordhaus.png Key Challenges: Couple hydrodynamics, nuclear reactions, and - eventually - general relativity and magnetism, to the non-thermal transport of six kinds of neutrinos...

  11. Supernova Neutrinos, LSND

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Certification Protocol Superior Energy Performance Certification Protocol Superior Energy Performance logo The Superior Energy Performance® (SEP(tm)) Certification Protocol describes the purpose of the SEP program and defines the steps required for participation-from initial application through certification by an ANSI-ANAB accredited Verification Body. Superior Energy Performance Certification Protocol (December 2012) (1.2 MB) More Documents & Publications Becoming a Certified Practitioner

  12. Supernovae and gamma-ray bursts: The moment of the formation of a black hole and a newly born neutron star

    SciTech Connect (OSTI)

    Ruffini, Remo, E-mail: ruffini@icra.it [Dip. di Fisica, Sapienza University of Rome and ICRA Piazzale Aldo Moro 5, I-00185, Rome (Italy); ICRANet, Piazzale della Repubblica 10, I-65122 Pescara (Italy); Universit de Nice Sophie Antipolis, Nice, CEDEX 2 Grand Chteau Parc Valros (Italy)

    2014-01-14

    We review recent progress in our understanding of the nature of gamma ray bursts (GRBs) and in particular, in the relationship between the short GRBs and the long GRBs. The coincidental occurence of a GRB with a Supernova (SN) is explained within the Induced Gravitational Collapse (IGC) paradigm, following the sequence: 1) an initial binary system consists in a compact Carbon-Oxygen (CO) core and a NS; 2) the CO core explodes giving origin to a SN and part of the SN ejecta accretes onto the NS which reaches its critical mass and collapses to a BH giving rise to a long GRB; 3) a new NS is generated by the SN as a remnant. The observational consequences of this scenario are outlined. The first example of a short GRB is given.

  13. CO J = 1-0 AND J = 2-1 LINE OBSERVATIONS OF THE MOLECULAR-CLOUD-BLOCKED SUPERNOVA REMNANT 3C434.1

    SciTech Connect (OSTI)

    Jeong, Il-Gyo; Koo, Bon-Chul; Cho, Wan-Kee; Kramer, Carsten; Stutzki, Juergen; Byun, Do-Young E-mail: koo@astro.snu.ac.kr

    2013-06-20

    We present the results of CO emission line observations toward the semicircular Galactic supernova remnant (SNR) 3C434.1 (G94.0+1.0). We mapped an area covering the whole SNR in the {sup 12}CO J = 1-0 emission line using the Seoul Radio Astronomy Observatory 6 m telescope and found a large molecular cloud superposed on the faint western part of the SNR. The cloud was elongated along the north-south direction and showed a very good spatial correlation with the radio features of the SNR. We carried out {sup 12}CO J = 2-1 line observations of this cloud using the Koelner Observatorium fuer Sub-Millimeter Astronomie 3 m telescope and found a region in which the {sup 12}CO J = 2-1 to J = 1-0 ratio was high ({approx}1.6). This higher excitation, together with the morphological relation, strongly suggested that the molecular cloud was interacting with the SNR. The systemic velocity of the molecular cloud (-13 km s{sup -1}) gave a kinematic distance of 3.0 kpc to the SNR-molecular cloud system. We derived the physical parameters of the SNR based on this new distance. We examined the variation of the radio spectral index over the remnant and found that it was flatter in the western part, wherein the SNR was interacting with the molecular cloud. We therefore propose that 3C434.1 is the remnant of a supernova explosion that occurred just outside the boundary of a relatively thin, sheet-like molecular cloud. We present a hydrodynamic model showing that its asymmetric radio morphology can result from its interaction with this blocking molecular cloud.

  14. THE INFLUENCE OF SUPERNOVA REMNANTS ON THE INTERSTELLAR MEDIUM IN THE LARGE MAGELLANIC CLOUD SEEN AT 20-600 μm WAVELENGTHS

    SciTech Connect (OSTI)

    Lakićević, Maša; Van Loon, Jacco Th.; Meixner, Margaret; Gordon, Karl; Roman-Duval, Julia; Seale, Jonathan; Bot, Caroline; Babler, Brian; Bolatto, Alberto; Engelbracht, Chad; Misselt, Karl; Montiel, Edward; Filipović, Miroslav; Hony, Sacha; Okumura, K.; Panuzzo, Pasquale; Sauvage, Marc; Patat, Ferdinando; Sonneborn, George; and others

    2015-01-20

    We present the analysis of supernova remnants (SNRs) in the Large Magellanic Cloud (LMC) and their influence on the environment at far-infrared (FIR) and submillimeter wavelengths. We use new observations obtained with the Herschel Space Observatory and archival data obtained with the Spitzer Space Telescope, to make the first FIR atlas of these objects. The SNRs are not clearly discernible at FIR wavelengths; however, their influence becomes apparent in maps of dust mass and dust temperature, which we constructed by fitting a modified blackbody to the observed spectral energy distribution in each sightline. Most of the dust that is seen is pre-existing interstellar dust in which SNRs leave imprints. The temperature maps clearly reveal SNRs heating surrounding dust, while the mass maps indicate the removal of 3.7{sub −2.5}{sup +7.5} M {sub ☉} of dust per SNR. This agrees with the calculations by others that significant amounts of dust are sputtered by SNRs. Under the assumption that dust is sputtered and not merely pushed away, we estimate a dust destruction rate in the LMC of 0.037{sub −0.025}{sup +0.075} M {sub ☉} yr{sup –1} due to SNRs, yielding an average lifetime for interstellar dust of 2{sub −1.3}{sup +4.0}×10{sup 7} yr. We conclude that sputtering of dust by SNRs may be an important ingredient in models of galactic evolution, that supernovae may destroy more dust than they produce, and that they therefore may not be net producers of long lived dust in galaxies.

  15. Computer Code Gives Astrophysicists First Full Simulation of Star's Final Hours

    ScienceCinema (OSTI)

    Applin, Bradford

    2013-05-29

    The precise conditions inside a white dwarf star in the hours leading up to its explosive end as a Type Ia supernova are one of the mysteries confronting astrophysicists studying these massive stellar explosions. But now, a team of researchers, composed of three applied mathematicians at the U.S. Department of Energy's (DOE) Lawrence Berkeley National Laboratory and two astrophysicists, has created the first full-star simulation of the hours preceding the largest thermonuclear explosions in the universe. http://www.lbl.gov/cs/Archive/news091509.html

  16. Fusion reactions in nuclear astrophysics: The MUSIC approach

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    reactions in nuclear astrophysics: The MUSIC approach The MUSIC approach Sergio Almaraz-Calderon Sergio Almaraz-Calderon Physics Division Argonne National Laboratory 2014 ATLAS USER'S MEETING 05/15/2014 Carbon burning reactions in the stars Carbon burning in massive stars Ignition phase of Type Ia supernovae X-ray binaries NASA/CXC/PSU/L University of Chicago Flash Center S. Almaraz-Calderon ATLAS user's meeting 05/15/2014 H. Schatz X-Ray Bursts and Superbursts ● H and He burning (rp-process)

  17. Maximum mass of stable magnetized highly super-Chandrasekhar white dwarfs: stable solutions with varying magnetic fields

    SciTech Connect (OSTI)

    Das, Upasana; Mukhopadhyay, Banibrata E-mail: bm@physics.iisc.ernet.in

    2014-06-01

    We address the issue of stability of recently proposed significantly super-Chandrasekhar white dwarfs. We present stable solutions of magnetostatic equilibrium models for super-Chandrasekhar white dwarfs pertaining to various magnetic field profiles. This has been obtained by self-consistently including the effects of the magnetic pressure gradient and total magnetic density in a general relativistic framework. We estimate that the maximum stable mass of magnetized white dwarfs could be more than 3 solar mass. This is very useful to explain peculiar, overluminous type Ia supernovae which do not conform to the traditional Chandrasekhar mass-limit.

  18. Tornado type wind turbines

    DOE Patents [OSTI]

    Hsu, Cheng-Ting

    1984-01-01

    A tornado type wind turbine has a vertically disposed wind collecting tower with spaced apart inner and outer walls and a central bore. The upper end of the tower is open while the lower end of the structure is in communication with a wind intake chamber. An opening in the wind chamber is positioned over a turbine which is in driving communication with an electrical generator. An opening between the inner and outer walls at the lower end of the tower permits radially flowing air to enter the space between the inner and outer walls while a vertically disposed opening in the wind collecting tower permits tangentially flowing air to enter the central bore. A porous portion of the inner wall permits the radially flowing air to interact with the tangentially flowing air so as to create an intensified vortex flow which exits out of the top opening of the tower so as to create a low pressure core and thus draw air through the opening of the wind intake chamber so as to drive the turbine.

  19. Observational constraints on late-time {lambda}(t) cosmology

    SciTech Connect (OSTI)

    Carneiro, S.; Pigozzo, C.; Dantas, M. A.; Alcaniz, J. S.

    2008-04-15

    The cosmological constant {lambda}, i.e., the energy density stored in the true vacuum state of all existing fields in the Universe, is the simplest and the most natural possibility to describe the current cosmic acceleration. However, despite its observational successes, such a possibility exacerbates the well-known {lambda} problem, requiring a natural explanation for its small, but nonzero, value. In this paper we study cosmological consequences of a scenario driven by a varying cosmological term, in which the vacuum energy density decays linearly with the Hubble parameter, {lambda}{proportional_to}H. We test the viability of this scenario and study a possible way to distinguish it from the current standard cosmological model by using recent observations of type Ia supernova (Supernova Legacy Survey Collaboration), measurements of the baryonic acoustic oscillation from the Sloan Digital Sky Survey, and the position of the first peak of the cosmic microwave background angular spectrum from the three-year Wilkinson Microwave Anisotropy Probe.

  20. TITLE AUTHORS SUBJECT SUBJECT RELATED DESCRIPTION PUBLISHER AVAILABILI...

    Office of Scientific and Technical Information (OSTI)

    Systematic Effects in Type a Supernovae Surveys from Host Galaxy Spectra Strauss Michael A Princeton University ASTRONOMY AND ASTROPHYSICS Cosmology supernovae stellar populations...

  1. Window Types | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Window Types Window Types A wood-frame window with insulated window glazing. | Photo courtesy of ©iStockphoto/chandlerphoto A wood-frame window with insulated window glazing. | Photo courtesy of ©iStockphoto/chandlerphoto Windows come in a number of different frame and glazing types. By combining an energy-efficient frame choice with a glazing type tailored to your climate and application, you can customize each of your home's windows. Types of Window Frames Improving the thermal resistance

  2. Types of Lighting in Commercial Buildings - Lighting Types

    U.S. Energy Information Administration (EIA) Indexed Site

    is termed fluorescence). A ballast is required to regulate and control the current and voltage. Two types of ballasts are used, magnetic and electronic. Electronic ballasts have...

  3. Luminosity distance in 'Swiss cheese' cosmology with randomized voids. I. Single void size

    SciTech Connect (OSTI)

    Vanderveld, R. Ali; Flanagan, Eanna E.; Wasserman, Ira

    2008-10-15

    Recently, there have been suggestions that the Type Ia supernova data can be explained using only general relativity and cold dark matter with no dark energy. In 'Swiss cheese' models of the Universe, the standard Friedmann-Robertson-Walker picture is modified by the introduction of mass-compensating spherical inhomogeneities, typically described by the Lemaitre-Tolman-Bondi metric. If these inhomogeneities correspond to underdense cores surrounded by mass-compensating overdense shells, then they can modify the luminosity distance-redshift relation in a way that can mimic accelerated expansion. It has been argued that this effect could be large enough to explain the supernova data without introducing dark energy or modified gravity. We show that the large apparent acceleration seen in some models can be explained in terms of standard weak field gravitational lensing together with insufficient randomization of void locations. The underdense regions focus the light less than the homogeneous background, thus dimming supernovae in a way that can mimic the effects of acceleration. With insufficient randomization of the spatial location of the voids and of the lines of sight, coherent defocusing can lead to anomalously large demagnification effects. We show that a proper randomization of the voids and lines of sight reduces the effect to the point that it can no longer explain the supernova data.

  4. VERY LATE PHOTOMETRY OF SN 2011fe

    SciTech Connect (OSTI)

    Kerzendorf, W. E. [Department of Astronomy and Astrophysics, University of Toronto, 50 Saint George Street, Toronto, ON M5S 3H4 (Canada); Taubenberger, S.; Seitenzahl, I. R.; Ruiter, A. J., E-mail: wkerzendorf@gmail.com [Max-Planck-Institut fr Astrophysik, Karl-Schwarzschild-Strae 1, D-85748 Garching (Germany)

    2014-12-01

    The Type Ia supernova SN 2011fe is one of the closest supernovae of the past decades. Due to its proximity and low dust extinction, this object provides a very rare opportunity to study the extremely late time evolution (>900 days) of thermonuclear supernovae. In this Letter, we present our photometric data of SN 2011fe taken at an unprecedented late epoch of ?930 days with GMOS-N mounted on the Gemini North telescope (g=23.43 0.28, r=24.14 0.14, i=23.91 0.18, and z=23.90 0.17) to study the energy production and retention in the ejecta of SN 2011fe. Together with previous measurements by other groups, our result suggests that the optical supernova light curve can still be explained by the full thermalization of the decay positrons of {sup 56}Co. This is in spite of theoretical predicted effects (e.g., infrared catastrophe, positron escape, and dust) that advocate a substantial energy redistribution and/or loss via various processes that result in a more rapid dimming at these very late epochs.

  5. BUILDING LATE-TYPE SPIRAL GALAXIES BY IN-SITU AND EX-SITU STAR FORMATION

    SciTech Connect (OSTI)

    Pillepich, Annalisa; Madau, Piero; Mayer, Lucio

    2015-02-01

    We analyze the formation and evolution of the stellar components in ''Eris'', a 120pc resolution cosmological hydrodynamic simulation of a late-type spiral galaxy. The simulation includes the effects of a uniform UV background, a delayed-radiative-cooling scheme for supernova feedback, and a star formation recipe based on a high gas density threshold. It allows a detailed study of the relative contributions of ''in-situ'' (within the main host) and ''ex-situ'' (within satellite galaxies) star formation to each major Galactic component in a close Milky Way analog. We investigate these two star-formation channels as a function of galactocentric distance, along different lines of sight above and along the disk plane, and as a function of cosmic time. We find that: (1) approximately 70% of today's stars formed in-situ; (2) more than two thirds of the ex-situ stars formed within satellites after infall; (3) the majority of ex-situ stars are found today in the disk and in the bulge; (4) the stellar halo is dominated by ex-situ stars, whereas in-situ stars dominate the mass profile at distances ? 5 kpc from the center at high latitudes; and (5) approximately 25% of the inner, r ? 20 kpc, halo is composed of in-situ stars that have been displaced from their original birth sites during Eris' early assembly history.

  6. DIORAMA Location Type User's Guide

    SciTech Connect (OSTI)

    Terry, James Russell

    2015-01-29

    The purpose of this report is to present the current design and implementation of the DIORAMA location type object (LocationType) and to provide examples and use cases. The LocationType object is included in the diorama-app package in the diorama::types namespace. Abstractly, the object is intended to capture the full time history of the location of an object or reference point. For example, a location may be speci ed as a near-Earth orbit in terms of a two-line element set, in which case the location type is capable of propagating the orbit both forward and backward in time to provide a location for any given time. Alternatively, the location may be speci ed as a xed set of geodetic coordinates (latitude, longitude, and altitude), in which case the geodetic location of the object is expected to remain constant for all time. From an implementation perspective, the location type is de ned as a union of multiple independent objects defi ned in the DIORAMA tle library. Types presently included in the union are listed and described in subsections below, and all conversions or transformation between these location types are handled by utilities provided by the tle library with the exception of the \\special-values" location type.

  7. Window Types | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    its U-factor. There are advantages and disadvantages to all types of frame materials, but vinyl, wood, fiberglass, and some composite frame materials provide greater...

  8. FERMI-LAT OBSERVATIONS OF SUPERNOVA REMNANTS INTERACTING WITH MOLECULAR CLOUDS: W41, MSH 17-39, AND G337.7-0.1

    SciTech Connect (OSTI)

    Castro, Daniel; Figueroa-Feliciano, Enectali; Slane, Patrick; Carlton, Ashley

    2013-09-01

    We report the detection of {gamma}-ray emission coincident with three supernova remnants (SNRs) using data from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. W41, G337.7-0.1, and MSH 17-39 are SNRs known to be interacting with molecular clouds, as evidenced by observations of hydroxyl (OH) maser emission at 1720 MHz in their directions and other observational information. SNR shocks are expected to be sites of cosmic-ray acceleration, and clouds of dense material can provide effective targets for production of {gamma}-rays from {pi}{sup 0}-decay. The observations reveal unresolved sources in the direction of G337.7-0.1 and MSH 17-39 and an extended source coincident with W41. We model their broadband emission (radio to {gamma}-ray) using a simple one-zone model, and after considering scenarios in which the MeV-TeV sources originate from either {pi}{sup 0}-decay or leptonic emission, we conclude that the {gamma}-rays are most likely produced through the hadronic channel.

  9. MULTI-WAVELENGTH OBSERVATIONS OF THE RADIO MAGNETAR PSR J1622-4950 AND DISCOVERY OF ITS POSSIBLY ASSOCIATED SUPERNOVA REMNANT

    SciTech Connect (OSTI)

    Anderson, Gemma E.; Gaensler, B. M.; Slane, Patrick O.; Drake, Jeremy J.; Rea, Nanda; Kaplan, David L.; Posselt, Bettina; Levin, Lina; Bailes, Matthew; Ramesh Bhat, N. D.; Johnston, Simon; Burke-Spolaor, Sarah; Murray, Stephen S.; Brogan, Crystal L.; Bates, Samuel; Benjamin, Robert A.; Burgay, Marta; D'Amico, Nichi; Esposito, Paolo; and others

    2012-05-20

    We present multi-wavelength observations of the radio magnetar PSR J1622-4950 and its environment. Observations of PSR J1622-4950 with Chandra (in 2007 and 2009) and XMM (in 2011) show that the X-ray flux of PSR J1622-4950 has decreased by a factor of {approx}50 over 3.7 years, decaying exponentially with a characteristic time of {tau} = 360 {+-} 11 days. This behavior identifies PSR J1622-4950 as a possible addition to the small class of transient magnetars. The X-ray decay likely indicates that PSR J1622-4950 is recovering from an X-ray outburst that occurred earlier in 2007, before the 2007 Chandra observations. Observations with the Australia Telescope Compact Array show strong radio variability, including a possible radio flaring event at least one and a half years after the 2007 X-ray outburst that may be a direct result of this X-ray event. Radio observations with the Molonglo Observatory Synthesis Telescope reveal that PSR J1622-4950 is 8' southeast of a diffuse radio arc, G333.9+0.0, which appears non-thermal in nature and which could possibly be a previously undiscovered supernova remnant (SNR). If G333.9+0.0 is an SNR then the estimates of its size and age, combined with the close proximity and reasonable implied velocity of PSR J1622-4950, suggest that these two objects could be physically associated.

  10. Archived Reference Building Type: Hospital

    Broader source: Energy.gov [DOE]

    Here you will find past versions of the commercial reference building models for existing buildings constructed before 1980, organized by building type and location. A summary ofbuilding types and climate zones is available for reference. Current versions are also available.

  11. Archived Reference Building Type: Hospital

    Broader source: Energy.gov [DOE]

    Here you will find past versions of the commercial reference building models for existing buildings constructed in or after 1980, organized by building type and location. A summary of building types and climate zones is available for reference. Current versions are also available.

  12. Archived Reference Building Type: Warehouse

    Broader source: Energy.gov [DOE]

    Here you will find past versions of the commercial reference building models for existing buildings constructed before 1980, organized by building type and location. A summary ofbuilding types and climate zones is available for reference. Current versions are also available.

  13. Archived Reference Building Type: Warehouse

    Broader source: Energy.gov [DOE]

    Here you will find past versions of the commercial reference building models for existing buildings constructed in or after 1980, organized by building type and location. A summary of building types and climate zones is available for reference. Current versions are also available.

  14. Archived Reference Building Type: Supermarket

    Broader source: Energy.gov [DOE]

    Here you will find past versions of the commercial reference building models for existing buildings constructed in or after 1980, organized by building type and location. A summary of building types and climate zones is available for reference. Current versions are also available.

  15. P-type gallium nitride

    DOE Patents [OSTI]

    Rubin, Michael; Newman, Nathan; Fu, Tracy; Ross, Jennifer; Chan, James

    1997-01-01

    Several methods have been found to make p-type gallium nitride. P-type gallium nitride has long been sought for electronic devices. N-type gallium nitride is readily available. Discovery of p-type gallium nitride and the methods for making it will enable its use in ultraviolet and blue light-emitting diodes and lasers. pGaN will further enable blue photocathode elements to be made. Molecular beam epitaxy on substrates held at the proper temperatures, assisted by a nitrogen beam of the proper energy produced several types of p-type GaN with hole concentrations of about 5.times.10.sup.11 /cm.sup.3 and hole mobilities of about 500 cm.sup.2 /V-sec, measured at 250.degree. K. P-type GaN can be formed of unintentionally-doped material or can be doped with magnesium by diffusion, ion implantation, or co-evaporation. When applicable, the nitrogen can be substituted with other group III elements such as Al.

  16. P-type gallium nitride

    DOE Patents [OSTI]

    Rubin, M.; Newman, N.; Fu, T.; Ross, J.; Chan, J.

    1997-08-12

    Several methods have been found to make p-type gallium nitride. P-type gallium nitride has long been sought for electronic devices. N-type gallium nitride is readily available. Discovery of p-type gallium nitride and the methods for making it will enable its use in ultraviolet and blue light-emitting diodes and lasers. pGaN will further enable blue photocathode elements to be made. Molecular beam epitaxy on substrates held at the proper temperatures, assisted by a nitrogen beam of the proper energy produced several types of p-type GaN with hole concentrations of about 5{times}10{sup 11} /cm{sup 3} and hole mobilities of about 500 cm{sup 2} /V-sec, measured at 250 K. P-type GaN can be formed of unintentionally-doped material or can be doped with magnesium by diffusion, ion implantation, or co-evaporation. When applicable, the nitrogen can be substituted with other group III elements such as Al. 9 figs.

  17. Can MONDian vector theories explain the cosmic speed up?

    SciTech Connect (OSTI)

    Cardone, Vincenzo F.; Radicella, Ninfa

    2009-09-15

    Generalized Einstein-Aether vector field models have been shown to provide, in the weak field regime, modifications to gravity which can be reconciled with the successful modified Newtonian dynamics (MOND) proposal. Very little is known, however, on the function F(K) defining the vector field Lagrangian so that an analysis of the viability of such theories at the cosmological scales has never been performed. As a first step along this route, we rely on the relation between F(K) and the MOND interpolating function {mu}(a/a{sub 0}) to assign the vector field Lagrangian thus obtaining what we refer to as MONDian vector models. Since they are able by construction to recover the MOND successes on galaxy scales, we investigate whether they can also drive the observed accelerated expansion by fitting the models to the type Ia supernovae data. Should this be the case, we have a unified framework where both dark energy and dark matter can be seen as different manifestations of a single vector field. It turns out that both MONDian vector models are able to well fit the low redshift data on type Ia supernovae, while some tension could be present in the high z regime.

  18. Power-law wrinkling turbulence-flame interaction model for astrophysical flames

    SciTech Connect (OSTI)

    Jackson, Aaron P.; Townsley, Dean M.; Calder, Alan C.

    2014-04-01

    We extend a model for turbulence-flame interactions (TFI) to consider astrophysical flames with a particular focus on combustion in Type Ia supernovae. The inertial range of the turbulent cascade is nearly always under-resolved in simulations of astrophysical flows, requiring the use of a model in order to quantify the effects of subgrid-scale wrinkling of the flame surface. We provide implementation details to extend a well-tested TFI model to low-Prandtl number flames for use in the compressible hydrodynamics code FLASH. A local, instantaneous measure of the turbulent velocity is calibrated for FLASH and verification tests are performed. Particular care is taken to consider the relation between the subgrid rms turbulent velocity and the turbulent flame speed, especially for high-intensity turbulence where the turbulent flame speed is not expected to scale with the turbulent velocity. Finally, we explore the impact of different TFI models in full-star, three-dimensional simulations of Type Ia supernovae.

  19. Property:Water Type | Open Energy Information

    Open Energy Info (EERE)

    Type Jump to: navigation, search Property Name Water Type Property Type String Pages using the property "Water Type" Showing 25 pages using this property. (previous 25) (next 25) 1...

  20. Toward connecting core-collapse supernova theory with observations. I. Shock revival in a 15 M {sub ☉} blue supergiant progenitor with SN 1987A energetics

    SciTech Connect (OSTI)

    Handy, Timothy; Plewa, Tomasz; Odrzywołek, Andrzej

    2014-03-10

    We study the evolution of the collapsing core of a 15 M {sub ☉} blue supergiant supernova progenitor from the core bounce until 1.5 s later. We present a sample of hydrodynamic models parameterized to match the explosion energetics of SN 1987A. We find the spatial model dimensionality to be an important contributing factor in the explosion process. Compared to two-dimensional (2D) simulations, our three-dimensional (3D) models require lower neutrino luminosities to produce equally energetic explosions. We estimate that the convective engine in our models is 4% more efficient in 3D than in 2D. We propose that the greater efficiency of the convective engine found in 3D simulations might be due to the larger surface-to-volume ratio of convective plumes, which aids in distributing energy deposited by neutrinos. We do not find evidence of the standing accretion shock instability or turbulence being a key factor in powering the explosion in our models. Instead, the analysis of the energy transport in the post-shock region reveals characteristics of penetrative convection. The explosion energy decreases dramatically once the resolution is inadequate to capture the morphology of convection on large scales. This shows that the role of dimensionality is secondary to correctly accounting for the basic physics of the explosion. We also analyze information provided by particle tracers embedded in the flow and find that the unbound material has relatively long residency times in 2D models, while in 3D a significant fraction of the explosion energy is carried by particles with relatively short residency times.