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  1. 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 ...

  2. Defining photometric peculiar type Ia supernovae

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    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.

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

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    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.

  4. 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.

  5. 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.

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

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    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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

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

    SciTech Connect (OSTI)

    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.

  13. 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.

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

    Office of Scientific and Technical Information (OSTI)

    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...

  15. 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...

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

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    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}.

  17. 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.

  18. 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.

  19. Signatures of a companion star in type Ia supernovae

    SciTech Connect (OSTI)

    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.

  20. 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.

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

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    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.

  2. Ideal bandpasses for type Ia supernova cosmology

    SciTech Connect (OSTI)

    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.

  3. 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.

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

    Office of Scientific and Technical Information (OSTI)

    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 ...

  5. 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.

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

    Office of Scientific and Technical Information (OSTI)

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

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

    Office of Scientific and Technical Information (OSTI)

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

  8. 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.

  9. 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.

  10. 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.

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

    Office of Scientific and Technical Information (OSTI)

    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 ...

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. 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...

  17. 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.

  18. 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.

  19. 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:

  20. 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.

  1. 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.

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

    Office of Scientific and Technical Information (OSTI)

    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

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

    Office of Scientific and Technical Information (OSTI)

    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

  4. 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.

  5. 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.

  6. 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}.

  7. 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.

  8. 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

  9. 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.

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

    Office of Scientific and Technical Information (OSTI)

    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...

  11. 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}.

  12. Low Mach Number Modeling of Type Ia Supernovae

    SciTech Connect (OSTI)

    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.

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

    Office of Scientific and Technical Information (OSTI)

    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. ...

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

    Office of Scientific and Technical Information (OSTI)

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

  15. 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.

  16. 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 ...

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. SNE TRAFIC GENERATOR

    Energy Science and Technology Software Center (OSTI)

    003027MLTPL00 Network Traffic Generator for Low-rate Small Network Equipment Software http://eln.lbl.gov/sne_traffic_gen.html

  6. 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}.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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 ...

  13. 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.

  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. 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.

  16. 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...

  17. 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.

  18. 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).

  19. 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.

  20. 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

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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. ...

  10. 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.

  11. 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%.

  12. 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.

  13. 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 ...

  14. 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; ...

  15. 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.

  16. 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.

  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. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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 ...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. 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...

  18. 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...

  19. 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.

  20. 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. ; ...

  1. 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 ...

  2. 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. ...

  3. 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, ...

  4. 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 ...

  5. 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, ...

  6. 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. ...

  7. 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, ...

  8. 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...

  9. 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 ...

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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....

  20. 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

  1. 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.

  2. 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 »

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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 ...

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  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. 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.

  18. 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.

  19. 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...

  20. 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...

  1. 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.

  2. 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.

  3. 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

  4. 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.

  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. 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.

  7. 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

  8. 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.

  9. 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

  10. 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 ...

  11. 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. ...

  12. 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, ...

  13. 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, ...

  14. 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, ...

  15. 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 ...

  16. 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. ...

  17. 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 ...

  18. 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. ...

  19. 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 ...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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 ...

  12. 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, ...

  13. 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 ...

  14. 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 ☉}.

  15. 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:...

  16. 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

  17. 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

  18. 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) ...

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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/

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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 ...

  3. 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,...

  4. 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 ...

  5. 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

  6. 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 ...

  7. 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.

  8. 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 ...

  9. 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...

  10. 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 ...

  11. 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 ...

  12. 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 ...

  13. 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...

  14. 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...

  15. 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.

  16. 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.

  17. 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.)

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  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. 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.

  9. 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.

  10. 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.