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Sample records for redshift space distortions

  1. Redshift-space distortions in massive neutrino and evolving dark...

    Office of Scientific and Technical Information (OSTI)

    Title: Redshift-space distortions in massive neutrino and evolving dark energy cosmologies Authors: Upadhye, Amol ; Kwan, Juliana ; Pope, Adrian ; Heitmann, Katrin ; Habib, Salman ...

  2. Nonlinear stochastic growth rates and redshift space distortions

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

    Jennings, Elise; Jennings, David

    2015-04-09

    The linear growth rate is commonly defined through a simple deterministic relation between the velocity divergence and the matter overdensity in the linear regime. We introduce a formalism that extends this to a nonlinear, stochastic relation between ? ? ?(x,t)/aH and ?. This provides a new phenomenological approach that examines the conditional mean (???), together with the fluctuations of ? around this mean. We measure these stochastic components using N-body simulations and find they are non-negative and increase with decreasing scale from ~10% at kmorerelation and nonlinearity are more pronounced for halos, M ? 5 x 10Mh?, compared to the dark matter at z 0 and 1. Nonlinear growth effects manifest themselves as a rotation of the mean (???) away from the linear theory prediction fLT?, where fLT is the linear growth rate. This rotation increases with wavenumber, k, and we show that it can be well-described by second order Lagrangian perturbation theory (2LPT) for k LT from two point statistics in redshift space. Given that the relationship between ? and ? is stochastic and nonlinear, this will have implications for the interpretation and precision of fLT extracted using models which assume a linear, deterministic expression.less

  3. Nonlinear stochastic growth rates and redshift space distortions

    SciTech Connect (OSTI)

    Jennings, Elise; Jennings, David

    2015-04-09

    The linear growth rate is commonly defined through a simple deterministic relation between the velocity divergence and the matter overdensity in the linear regime. We introduce a formalism that extends this to a nonlinear, stochastic relation between ? ? ?(x,t)/aH and ?. This provides a new phenomenological approach that examines the conditional mean (???), together with the fluctuations of ? around this mean. We measure these stochastic components using N-body simulations and find they are non-negative and increase with decreasing scale from ~10% at k<0.2hMpc? to 25% at k ~ 0.45hMpc? at z 0. Both the stochastic relation and nonlinearity are more pronounced for halos, M ? 5 x 10Mh?, compared to the dark matter at z 0 and 1. Nonlinear growth effects manifest themselves as a rotation of the mean (???) away from the linear theory prediction fLT?, where fLT is the linear growth rate. This rotation increases with wavenumber, k, and we show that it can be well-described by second order Lagrangian perturbation theory (2LPT) for k < 0.1 hMpc?. The stochasticity in the ? ? relation is not so simply described by 2LPT, and we discuss its impact on measurements of fLT from two point statistics in redshift space. Given that the relationship between ? and ? is stochastic and nonlinear, this will have implications for the interpretation and precision of fLT extracted using models which assume a linear, deterministic expression.

  4. Non-linear stochastic growth rates and redshift space distortions

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

    Jennings, Elise; Jennings, David

    2015-04-09

    The linear growth rate is commonly defined through a simple deterministic relation between the velocity divergence and the matter overdensity in the linear regime. We introduce a formalism that extends this to a non-linear, stochastic relation between θ = ∇ ∙ v(x,t)/aH and δ. This provides a new phenomenological approach that examines the conditional mean <θ|δ>, together with the fluctuations of θ around this mean. We also measure these stochastic components using N-body simulations and find they are non-negative and increase with decreasing scale from ~10 per cent at k < 0.2 h Mpc-1 to 25 per cent at kmore » ~ 0.45 h Mpc-1 at z = 0. Both the stochastic relation and non-linearity are more pronounced for haloes, M ≤ 5 × 1012 M⊙ h-1, compared to the dark matter at z = 0 and 1. Non-linear growth effects manifest themselves as a rotation of the mean <θ|δ> away from the linear theory prediction -fLTδ, where fLT is the linear growth rate. This rotation increases with wavenumber, k, and we show that it can be well-described by second-order Lagrangian perturbation theory (2LPT) fork < 0.1 h Mpc-1. Furthermore, the stochasticity in the θ – δ relation is not so simply described by 2LPT, and we discuss its impact on measurements of fLT from two-point statistics in redshift space. Furthermore, given that the relationship between δ and θ is stochastic and non-linear, this will have implications for the interpretation and precision of fLT extracted using models which assume a linear, deterministic expression.« less

  5. Disentangling Redshift-Space Distortions and Nonlinear Bias using the 2D Power Spectrum

    SciTech Connect (OSTI)

    Jennings, Elise; Wechsler, Risa H.

    2015-08-07

    We present the nonlinear 2D galaxy power spectrum, P(k, ), in redshift space, measured from the Dark Sky simulations, using galaxy catalogs constructed with both halo occupation distribution and subhalo abundance matching methods, chosen to represent an intermediate redshift sample of luminous red galaxies. We find that the information content in individual (cosine of the angle to the line of sight) bins is substantially richer then multipole moments, and show that this can be used to isolate the impact of nonlinear growth and redshift space distortion (RSD) effects. Using the < 0.2 simulation data, which we show is not impacted by RSD effects, we can successfully measure the nonlinear bias to an accuracy of ~ 5% at k < 0.6hMpc-1 . This use of individual bins to extract the nonlinear bias successfully removes a large parameter degeneracy when constraining the linear growth rate of structure. We carry out a joint parameter estimation, using the low simulation data to constrain the nonlinear bias, and > 0.2 to constrain the growth rate and show that f can be constrained to ~ 26(22)% to a kmax < 0.4(0.6)hMpc-1 from clustering alone using a simple dispersion model, for a range of galaxy models. Our analysis of individual bins also reveals interesting physical effects which arise simply from different methods of populating halos with galaxies. We also find a prominent turnaround scale, at which RSD damping effects are greater then the nonlinear growth, which differs not only for each bin but also for each galaxy model. These features may provide unique signatures which could be used to shed light on the galaxydark matter connection. Furthermore, the idea of separating nonlinear growth and RSD effects making use of the full information in the 2D galaxy power spectrum yields significant improvements in constraining cosmological parameters and may be a promising probe of galaxy formation models.

  6. Redshift distortions of galaxy correlation functions

    SciTech Connect (OSTI)

    Fry, J.N. Florida Univ., Gainesville, FL . Dept. of Physics); Gaztanaga, E. Oxford Univ. . Dept. of Physics)

    1993-05-12

    To examine how peculiar velocities can affect the 2-, 3-, and 4-point correlation functions, we evaluate volume-average correlations for configurations that emphasize and minimize distortions for four different volume-limited samples from each of the CfA, SSRS, and IRAS redshift catalogs. We present the results as the correlation length r[sub 0] and power index [gamma] of the 2-point correlation, [anti [Xi

  7. Dark matter and halo bispectrum in redshift space: theory and applications

    SciTech Connect (OSTI)

    Gil-Marn, Hctor; Percival, Will [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth PO1 3FX (United Kingdom); Wagner, Christian [Max-Planck-Institut fr Astrophysik, Karl-Schwarzschild Str. 1, 85741 Garching (Germany); Norea, Jorge [Department of Theoretical Physics and Center for Astroparticle Physics (CAP), 24 quai E. Ansermet, CH-1211 Geneva 4 (Switzerland); Verde, Licia, E-mail: hector.gil@port.ac.uk, E-mail: cwagner@mpa-garching.mpg.de, E-mail: jorge.norena@unige.ch, E-mail: liciaverde@icc.ub.edu, E-mail: will.percival@port.ac.uk [ICREA Instituci Catalana de Recerca i Estudis Avanats, Passeig Llus Companys 23, E-08010 Barcelona (Spain)

    2014-12-01

    We present a phenomenological modification of the standard perturbation theory prediction for the bispectrum in redshift space that allows us to extend the model to mildly non-linear scales over a wide range of redshifts, z?1.5. Our model require 18 free parameters that are fitted to N-body simulations using the shapes k{sub 2}/k{sub 1}=1,1.5,2.0,2.5. We find that we can describe the bispectrum of dark matter particles with ?5% accuracy for k{sub i}?<0.10h/Mpc at z=0, for k{sub i}?<0.15h/Mpc at z=0.5, for k{sub i}?<0.17h/Mpc at z=1.0 and for k{sub i}?<0.20h/Mpc at z=1.5. For very squeezed triangles with k{sub 1}=k{sub 2}?>0.1hMpc{sup -1} and k{sub 3}?0.02hMpc{sup -1}, however, neither SPT nor the proposed fitting formula are able to describe the measured dark matter bispectrum with this accuracy. We show that the fitting formula is sufficiently general that can be applied to other intermediate shapes such as k{sub 2}/k{sub 1}=1.25,1.75,and2.25. We also test that the fitting formula is able to describe with similar accuracy the bispectrum of cosmologies with different ?{sub m}, in the range 0.2?redshift space power spectrum monopole and quadrupole with the bispectrum monopole for both dark matter particles and haloes. We find that the combination of these three statistics can break the degeneracy between b{sub 1}, f and ?{sub 8}. For dark matter particles the new model can be used to recover f and ?{sub 8} with ?1% accuracy. For dark matter haloes we find that f and ?{sub 8} present larger systematic shifts, ?10%. The systematic offsets arise because of limitations in the modelling of the interplay between bias and redshift space distortions, and represent a limitation as the statistical errors of forthcoming surveys reach this level. Conveniently, we find that these residual systematics are mitigated for combinations of parameters. In particular, the quantity f?{sub 8} is still recovered with ?1% accuracy for the particular halo population and cosmology studied. The improvement on the modelling of the bispectrum presented in this paper will be useful for extracting information from current and future galaxy surveys.

  8. Early-type galaxies at intermediate redshift observed with Hubble space telescope WFC3: perspectives on recent star formation

    SciTech Connect (OSTI)

    Rutkowski, Michael J.; Jeong, Hyunjin; Yi, Sukyoung K.; Cohen, Seth H.; Windhorst, Rogier A.; Kaviraj, Sugata; Ryan, Russell E. Jr.; Koekemoer, Anton; Hathi, Nimish P.; Dopita, Michael A.

    2014-12-01

    We present an analysis of the stellar populations of 102 visually selected early-type galaxies (ETGs) with spectroscopic redshifts (0.35 ? z ? 1.5) from observations in the Early Release Science program with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). We fit one- and two-component synthetic stellar models to the ETGs UV-optical-near-IR spectral energy distributions and find that a large fraction (?40%) are likely to have experienced a minor (f{sub YC} ? 10% of stellar mass) burst of recent (t{sub YC} ? 1 Gyr) star formation. The measured age and mass fraction of the young stellar populations do not strongly trend with measurements of galaxy morphology. We note that massive (M > 10{sup 10.5} M {sub ?}) recent star-forming ETGs appear to have larger sizes. Furthermore, high-mass, quiescent ETGs identified with likely companions populate a distinct region in the size-mass parameter space, in comparison with the distribution of massive ETGs with evidence of recent star formation (RSF). We conclude that both mechanisms of quenching star formation in disk-like ETGs and (gas-rich, minor) merger activity contribute to the formation of young stars and the size-mass evolution of intermediate redshift ETGs. The number of ETGs for which we have both HST WFC3 panchromatic (especially UV) imaging and spectroscopically confirmed redshifts is relatively small, therefore, a conclusion about the relative roles of both of these mechanisms remains an open question.

  9. Testing cosmic geometry without dynamic distortions using voids

    SciTech Connect (OSTI)

    Hamaus, Nico; Sutter, P.M.; Lavaux, Guilhem; Wandelt, Benjamin D. E-mail: sutter@iap.fr E-mail: wandelt@iap.fr

    2014-12-01

    We propose a novel technique to probe the expansion history of the Universe based on the clustering statistics of cosmic voids. In particular, we compute their two-point statistics in redshift space on the basis of realistic mock galaxy catalogs and apply the Alcock-Paczynski test. In contrast to galaxies, we find void auto-correlations to be marginally affected by peculiar motions, providing a model-independent measure of cosmological parameters without systematics from redshift-space distortions. Because only galaxy-galaxy and void-galaxy correlations have been considered in these types of studies before, the presented method improves both statistical and systematic uncertainties on the product of angular diameter distance and Hubble rate, furnishing the potentially cleanest probe of cosmic geometry available to date.

  10. Cosmological constraints from the redshift dependence of the Alcock-Paczynski test: galaxy density gradient field

    SciTech Connect (OSTI)

    Li, Xiao-Dong; Park, Changbom; Forero-Romero, J. E.; Kim, Juhan E-mail: cbp@kias.re.kr E-mail: kjhan@kias.re.kr

    2014-12-01

    We propose a method based on the redshift dependence of the Alcock-Paczynski (AP) test to measure the expansion history of the universe. It uses the isotropy of the galaxy density gradient field to constrain cosmological parameters. If the density parameter ? {sub m} or the dark energy equation of state w are incorrectly chosen, the gradient field appears to be anisotropic with the degree of anisotropy varying with redshift. We use this effect to constrain the cosmological parameters governing the expansion history of the universe. Although redshift-space distortions (RSD) induced by galaxy peculiar velocities also produce anisotropies in the gradient field, these effects are close to uniform in magnitude over a large range of redshift. This makes the redshift variation of the gradient field anisotropy relatively insensitive to the RSD. By testing the method on mock surveys drawn from the Horizon Run 3 cosmological N-body simulations, we demonstrate that the cosmological parameters can be estimated without bias. Our method is complementary to the baryon acoustic oscillation or topology methods as it depends on D{sub AH} , the product of the angular diameter distance and the Hubble parameter.

  11. Combining weak-lensing tomography and spectroscopic redshift surveys

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

    Cai, Yan -Chuan; Bernstein, Gary

    2012-05-11

    Redshift space distortion (RSD) is a powerful way of measuring the growth of structure and testing General Relativity, but it is limited by cosmic variance and the degeneracy between galaxy bias b and the growth rate factor f. The cross-correlation of lensing shear with the galaxy density field can in principle measure b in a manner free from cosmic variance limits, breaking the f-b degeneracy and allowing inference of the matter power spectrum from the galaxy survey. We analyze the growth constraints from a realistic tomographic weak lensing photo-z survey combined with a spectroscopic galaxy redshift survey over the samemore » sky area. For sky coverage fsky = 0.5, analysis of the transverse modes measures b to 2-3% accuracy per Δz = 0.1 bin at z < 1 when ~10 galaxies arcmin–2 are measured in the lensing survey and all halos with M > Mmin = 1013h–1M⊙ have spectra. For the gravitational growth parameter parameter γ (f = Ωγm), combining the lensing information with RSD analysis of non-transverse modes yields accuracy σ(γ) ≈ 0.01. Adding lensing information to the RSD survey improves \\sigma(\\gamma) by an amount equivalent to a 3x (10x) increase in RSD survey area when the spectroscopic survey extends down to halo mass 1013.5 (1014) h–1 M⊙. We also find that the σ(γ) of overlapping surveys is equivalent to that of surveys 1.5-2 times larger if they are separated on the sky. This gain is greatest when the spectroscopic mass threshold is 1013 -1014 h–1 M⊙, similar to LRG surveys. The gain of overlapping surveys is reduced for very deep or very shallow spectroscopic surveys, but any practical surveys are more powerful when overlapped than when separated. As a result, the gain of overlapped surveys is larger in the case when the primordial power spectrum normalization is uncertain by > 0.5%.« less

  12. Probing correlations of early magnetic fields using ?-distortion

    SciTech Connect (OSTI)

    Ganc, Jonathan; Sloth, Martin S. E-mail: sloth@cp3.dias.sdu.dk

    2014-08-01

    The damping of a non-uniform magnetic field between the redshifts of about 10{sup 4} and 10{sup 6} injects energy into the photon-baryon plasma and causes the CMB to deviate from a perfect blackbody spectrum, producing a so-called ?-distortion. We can calculate the correlation (?T) of this distortion with the temperature anisotropy T of the CMB to search for a correlation (B{sup 2}?) between the magnetic field B and the curvature perturbation ?; knowing the (B{sup 2}?) correlation would help us distinguish between different models of magnetogenesis. Since the perturbations which produce the ?-distortion will be much smaller scale than the relevant density perturbations, the observation of this correlation is sensitive to the squeezed limit of (B{sup 2}?), which is naturally parameterized by b{sub NL} (a parameter defined analogously to f{sub NL}). We find that a PIXIE-like CMB experiments has a signal to noise S/N?1.0נb{sub NL}( B-tilde {sub ?}/10nG){sup 2}, where B-tilde {sub ?} is the magnetic field's strength on ?-distortion scales normalized to today's redshift; thus, a 10 nG field would be detectable with b{sub NL}=O(1). However, if the field is of inflationary origin, we generically expect it to be accompanied by a curvature bispectrum (?{sup 3}) induced by the magnetic field. For sufficiently small magnetic fields, the signal (B{sup 2}?) will dominate, but for B-tilde {sub ?}?>1 nG, one would have to consider the specifics of the inflationary magnetogenesis model. We also discuss the potential post-magnetogenesis sources of a (B{sup 2}?) correlation and explain why there will be no contribution from the evolution of the magnetic field in response to the curvature perturbation.

  13. A large-scale structure at redshift 1.71 in the Lockman Hole

    SciTech Connect (OSTI)

    Henry, J. Patrick; Hasinger, Gnther; Suh, Hyewon; Aoki, Kentaro; Finoguenov, Alexis; Fotopoulou, Sotiria; Salvato, Mara; Tanaka, Masayuki

    2014-01-01

    We previously identified LH146, a diffuse X-ray source in the Lockman Hole, as a galaxy cluster at redshift 1.753. The redshift was based on one spectroscopic value, buttressed by seven additional photometric redshifts. We confirm here the previous spectroscopic redshift and present concordant spectroscopic redshifts for an additional eight galaxies. The average of these nine redshifts is 1.714 0.012 (error on the mean). Scrutiny of the galaxy distribution in redshift space and the plane of the sky shows that there are two concentrations of galaxies near the X-ray source. In addition, there are three diffuse X-ray sources spread along the axis connecting the galaxy concentrations. LH146 is one of these three and lies approximately at the center of the two galaxy concentrations and the outer two diffuse X-ray sources. We thus conclude that LH146 is at the redshift initially reported but it is not a single virialized galaxy cluster, as previously assumed. Rather, it appears to mark the approximate center of a larger region containing more objects. For brevity, we refer to all these objects and their alignments as a large-scale structure. The exact nature of LH146 itself remains unclear.

  14. PULSAR PAIR CASCADES IN A DISTORTED MAGNETIC DIPOLE FIELD

    SciTech Connect (OSTI)

    Harding, Alice K.; Muslimov, Alex G.

    2011-01-01

    We investigate the effect of a distorted neutron star dipole magnetic field on pulsar pair cascade multiplicity and pair death lines. Using a simple model for a distorted dipole field that produces an offset polar cap (PC), we derive the accelerating electric field above the PC in space-charge-limited flow. We find that even a modest azimuthally asymmetric distortion can significantly increase the accelerating electric field on one side of the PC and, combined with a smaller field line radius of curvature, leads to larger pair multiplicity. The death line for producing pairs by curvature radiation moves downward in the P- P-dot diagram, allowing high pair multiplicities in a larger percentage of the radio pulsar population. These results could have important implications for the radio pulsar population, high energy pulsed emission, and the pulsar contribution to cosmic ray positrons.

  15. Space

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

    Space Space The Lab has explored space for more than 50 years and prompted many discoveries. Climb aboard our newest instruments and learn more about the planets and stars Curious about Mars and if life ever existed on the planet? Now you can learn all about the Red Planet and the Los Alamos technologies on board the Curiosity rover exploring Mars. Travel to Mars Curious about Mars and if life ever existed on the planet? Now you can learn all about the Red Planet and the Los Alamos technologies

  16. SPECTROSCOPIC REDSHIFTS OF GALAXIES WITHIN THE FRONTIER FIELDS

    SciTech Connect (OSTI)

    Ebeling, Harald; Ma, Cheng-Jiun; Barrett, Elizabeth

    2014-04-01

    We present a catalog of 1921 spectroscopic redshifts measured in the fields of the massive galaxy clusters MACSJ0416.12403 (z = 0.397), MACSJ0717.5+3745 (z = 0.546), and MACSJ1149.5+2223 (z = 0.544), i.e., three of the four clusters selected by Space Telescope Science Institute as the targets of the Frontier Fields (FFs) initiative for studies of the distant Universe via gravitational lensing. Compiled in the course of the Massive Cluster Survey project (MACS) that detected the FF clusters, this catalog is provided to the community for three purposes: (1) to allow the identification of cluster members for studies of the galaxy population of these extreme systems, (2) to facilitate the removal of unlensed galaxies and thus reduce shear dilution in weak-lensing analyses, and (3) to improve the calibration of photometric redshifts based on both ground- and spacebased observations of the FF clusters.

  17. Gravitational Redshift of Galaxies in Clusters from the Sloan...

    Office of Scientific and Technical Information (OSTI)

    Gravitational Redshift of Galaxies in Clusters from the Sloan Digital Sky Survey and the Baryon Oscillation Spectroscopic Survey Title: Gravitational Redshift of Galaxies in ...

  18. THE REDSHIFT EVOLUTION OF THE RELATION BETWEEN STELLAR MASS,...

    Office of Scientific and Technical Information (OSTI)

    REDSHIFT EVOLUTION OF THE RELATION BETWEEN STELLAR MASS, STAR FORMATION RATE, AND GAS METALLICITY OF GALAXIES Citation Details In-Document Search Title: THE REDSHIFT EVOLUTION OF ...

  19. Type Ia supernova rate measurements to redshift 2.5 from CANDELS: Searching

    Office of Scientific and Technical Information (OSTI)

    for prompt explosions in the early universe (Journal Article) | SciTech Connect Type Ia supernova rate measurements to redshift 2.5 from CANDELS: Searching for prompt explosions in the early universe Citation Details In-Document Search Title: Type Ia supernova rate measurements to redshift 2.5 from CANDELS: Searching for prompt explosions in the early universe The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) was a multi-cycle treasury program on the Hubble Space

  20. ACCOUNTING FOR COSMIC VARIANCE IN STUDIES OF GRAVITATIONALLY LENSED HIGH-REDSHIFT GALAXIES IN THE HUBBLE FRONTIER FIELD CLUSTERS

    SciTech Connect (OSTI)

    Robertson, Brant E.; Stark, Dan P.; Ellis, Richard S.; Dunlop, James S.; McLure, Ross J.; McLeod, Derek

    2014-12-01

    Strong gravitational lensing provides a powerful means for studying faint galaxies in the distant universe. By magnifying the apparent brightness of background sources, massive clusters enable the detection of galaxies fainter than the usual sensitivity limit for blank fields. However, this gain in effective sensitivity comes at the cost of a reduced survey volume and, in this Letter, we demonstrate that there is an associated increase in the cosmic variance uncertainty. As an example, we show that the cosmic variance uncertainty of the high-redshift population viewed through the Hubble Space Telescope Frontier Field cluster Abell 2744 increases from ?35% at redshift z ? 7 to ? 65% at z ? 10. Previous studies of high-redshift galaxies identified in the Frontier Fields have underestimated the cosmic variance uncertainty that will affect the ultimate constraints on both the faint-end slope of the high-redshift luminosity function and the cosmic star formation rate density, key goals of the Frontier Field program.

  1. REDSHIFT CATALOG FOR SWIFT LONG GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Xiao Limin; Schaefer, Bradley E., E-mail: lxiao1@lsu.edu [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States)

    2011-04-20

    We present a catalog of the redshifts for most long-duration gamma-ray bursts (GRBs) by Swift from 2004 December 20 to 2008 July 23 (258 bursts in total). All available information is collected, including spectroscopic redshifts, photometric redshift limits, and redshifts calculated from various luminosity relations. Error bars for the redshifts derived from the luminosity relations are asymmetric, with tails extended to the high-redshift end, and this effect is evaluated by looking at the 30% of Swift bursts with spectroscopic redshifts. A simulation is performed to eliminate this asymmetric effect, and the resultant redshift distribution is deconvolved. We test and confirm this simulation on the sample of bursts with known spectroscopic redshifts and then apply it to the 70% of Swift bursts that do not have spectroscopic measures. A final intrinsic redshift distribution is then made for almost all Swift bursts, and the efficiency of the spectroscopic detections is evaluated. The efficiency of spectroscopic redshifts varies from near unity at low redshift to 0.5 at z = 1, to near 0.3 at z = 4, and to 0.1 at z = 6. We also find that the fraction of GRBs with z>5 is {approx}10%, and this fraction is compared with simulations from a cosmological model.

  2. Reflective optical imaging system with balanced distortion

    SciTech Connect (OSTI)

    Chapman, Henry N.; Hudyma, Russell M.; Shafer, David R.; Sweeney, Donald W.

    1999-01-01

    An optical system compatible with short wavelength (extreme ultraviolet) An optical system compatible with short wavelength (extreme ultraviolet) radiation comprising four reflective elements for projecting a mask image onto a substrate. The four optical elements comprise, in order from object to image, convex, concave, convex and concave mirrors. The optical system is particularly suited for step and scan lithography methods. The invention enables the use of larger slit dimensions associated with ring field scanning optics, improves wafer throughput and allows higher semiconductor device density. The inventive optical system is characterized by reduced dynamic distortion because the static distortion is balanced across the slit width.

  3. Zigzag laser with reduced optical distortion

    DOE Patents [OSTI]

    Albrecht, Georg F. (Livermore, CA); Comaskey, Brian (Stockton, CA); Sutton, Steven B. (Manteca, CA)

    1994-01-01

    The architecture of the present invention has been driven by the need to solve the beam quality problems inherent in Brewster's angle tipped slab lasers. The entrance and exit faces of a solid state slab laser are cut perpendicular with respect to the pump face, thus intrinsically eliminating distortion caused by the unpumped Brewster's angled faces. For a given zigzag angle, the residual distortions inherent in the remaining unpumped or lightly pumped ends may be reduced further by tailoring the pump intensity at these ends.

  4. Zigzag laser with reduced optical distortion

    DOE Patents [OSTI]

    Albrecht, G.F.; Comaskey, B.; Sutton, S.B.

    1994-04-19

    The architecture of the present invention has been driven by the need to solve the beam quality problems inherent in Brewster's angle tipped slab lasers. The entrance and exit faces of a solid state slab laser are cut perpendicular with respect to the pump face, thus intrinsically eliminating distortion caused by the unpumped Brewster's angled faces. For a given zigzag angle, the residual distortions inherent in the remaining unpumped or lightly pumped ends may be reduced further by tailoring the pump intensity at these ends. 11 figures.

  5. Reflective optical imaging systems with balanced distortion

    DOE Patents [OSTI]

    Hudyma, Russell M. (San Ramon, CA)

    2001-01-01

    Optical systems compatible with extreme ultraviolet radiation comprising four reflective elements for projecting a mask image onto a substrate are described. The four optical elements comprise, in order from object to image, convex, concave, convex and concave mirrors. The optical systems are particularly suited for step and scan lithography methods. The invention enables the use of larger slit dimensions associated with ring field scanning optics, improves wafer throughput, and allows higher semiconductor device density. The inventive optical systems are characterized by reduced dynamic distortion because the static distortion is balanced across the slit width.

  6. On the recovery of the local group motion from galaxy redshift surveys

    SciTech Connect (OSTI)

    Nusser, Adi; Davis, Marc; Branchini, Enzo E-mail: mdavis@berkeley.edu

    2014-06-20

    There is an ?150 km s{sup 1} discrepancy between the measured motion of the Local Group (LG) of galaxies with respect to the cosmic microwave background and the linear theory prediction based on the gravitational force field of the large-scale structure in full-sky redshift surveys. We perform a variety of tests which show that the LG motion cannot be recovered to better than 150-200 km s{sup 1} in amplitude and within ?10 in direction. The tests rely on catalogs of mock galaxies identified in the Millennium simulation using semi-analytic galaxy formation models. We compare these results to the K{sub s} = 11.75 Two-Mass Galaxy Redshift Survey, which provides the deepest and most complete all-sky spatial distribution of galaxies with spectroscopic redshifts available thus far. In our analysis, we use a new concise relation for deriving the LG motion and bulk flow from the true distribution of galaxies in redshift space. Our results show that the main source of uncertainty is the small effective depth of surveys like the Two-Mass Redshift Survey (2MRS), which prevents a proper sampling of the large-scale structure beyond ?100 h {sup 1} Mpc. Deeper redshift surveys are needed to reach the 'convergence scale' of ?250 h {sup 1} Mpc in a ?CDM universe. Deeper surveys would also mitigate the impact of the 'Kaiser rocket' which, in a survey like 2MRS, remains a significant source of uncertainty. Thanks to the quiet and moderate density environment of the LG, purely dynamical uncertainties of the linear predictions are subdominant at the level of ?90 km s{sup 1}. Finally, we show that deviations from linear galaxy biasing and shot noise errors provide a minor contribution to the total error budget.

  7. ON THE REDSHIFT OF THE VERY HIGH ENERGY BLAZAR 3C 66A

    SciTech Connect (OSTI)

    Furniss, A.; Williams, D. A. [Santa Cruz Institute of Particle Physics and Department of Physics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States)] [Santa Cruz Institute of Particle Physics and Department of Physics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Fumagalli, M. [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)] [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Danforth, C. [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States)] [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Prochaska, J. X. [Department of Astronomy and Astrophysics, UCO/Lick Observatory, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States)] [Department of Astronomy and Astrophysics, UCO/Lick Observatory, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States)

    2013-03-20

    As a bright gamma-ray source, 3C 66A is of great interest to the high-energy astrophysics community, having a potential for placing cosmological constraints on models for the extragalactic background light (EBL) and the processes which contribute to this photon field. No firm spectroscopic redshift measurement has been possible for this blazar due to a lack of intrinsic emission and absorption features in optical spectra. We present new far-ultraviolet spectra from the Hubble Space Telescope/Cosmic Origins Spectrograph (HST/COS) of the BL Lac object 3C 66A covering the wavelength range 1132-1800 A. The data show a smooth continuum with intergalactic medium absorption features which can be used to place a firm lower limit on the blazar redshift of z {>=} 0.3347. An upper limit is set by statistically treating the non-detection of additional absorbers beyond z = 0.3347, indicating a redshift of less than 0.41 at 99% confidence and ruling out z {>=} 0.444 at 99.9% confidence. We conclude by showing how the redshift limits derived from the COS spectra remove the potential for this gamma-ray emitting blazar to place an upper limit on the flux of the EBL using high energy data from a flare in 2009 October.

  8. The Efficacy of Galaxy Shape Parameters in Photometric Redshift Estimation:

    Office of Scientific and Technical Information (OSTI)

    A Neural Network Approach (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: The Efficacy of Galaxy Shape Parameters in Photometric Redshift Estimation: A Neural Network Approach Citation Details In-Document Search Title: The Efficacy of Galaxy Shape Parameters in Photometric Redshift Estimation: A Neural Network Approach We present a determination of the effects of including galaxy morphological parameters in photometric redshift estimation with an

  9. Prediction of Part Distortion in Die Casting

    SciTech Connect (OSTI)

    R. Allen Miller

    2005-03-30

    The die casting process is one of the net shape manufacturing techniques and is widely used to produce high production castings with tight tolerances for many industries. An understanding of the stress distribution and the deformation pattern of parts produced by die casting will result in less deviation from the part design specification, a better die design and eventually more productivity and cost savings. This report presents methods that can be used to simulate the die casting process in order to predict the deformation and stresses in the produced part and assesses the degree to which distortion modeling is practical for die casting at the current time. A coupled thermal-mechanical finite elements model was used to simulate the die casting process. The simulation models the effect of thermal and mechanical interaction between the casting and the die. It also includes the temperature dependant material properties of the casting. Based on a designed experiment, a sensitivity analysis was conducted on the model to investigate the effect of key factors. These factors include the casting material model, material properties and thermal interaction between casting and dies. To verify the casting distortion predictions, it was compared against the measured dimensions of produced parts. The comparison included dimensions along and across the parting plane and the flatness of one surface.

  10. Compact quiescent galaxies at intermediate redshifts {sup ,}

    SciTech Connect (OSTI)

    Hsu, Li-Yen; Stockton, Alan; Shih, Hsin-Yi

    2014-12-01

    From several searches of the area common to the Sloan Digital Sky Survey and the United Kingdom Infrared Telescope Infrared Deep Sky Survey, we have selected 22 luminous galaxies between z ? 0.4 and z ? 0.9 that have colors and sizes similar to those of the compact quiescent galaxies at z > 2. By exploring structural parameters and stellar populations, we found that most of these galaxies actually formed most of their stars at z < 2 and are generally less compact than those found at z > 2. Several of these young objects are disk-like or possibly prolate. This lines up with several previous studies that found that massive quiescent galaxies at high redshifts often have disk-like morphologies. If these galaxies were to be confirmed to be disk-like, their formation mechanism must be able to account for both compactness and disks. On the other hand, if these galaxies were to be confirmed to be prolate, the fact that prolate galaxies do not exist in the local universe would indicate that galaxy formation mechanisms have evolved over cosmic time. We also found five galaxies forming over 80% of their stellar masses at z > 2. Three of these galaxies appear to have been modified to have spheroid-like morphologies, in agreement with the scenario of 'inside-out' buildup of massive galaxies. The remaining galaxies, SDSS J014355.21+133451.4 and SDSS J115836.93+021535.1, have truly old stellar populations and disk-like morphologies. These two objects would be good candidates for nearly unmodified compact quiescent galaxies from high redshifts that are worth future study.

  11. Catastrophic photometric redshift errors: Weak-lensing survey requirements

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

    Bernstein, Gary; Huterer, Dragan

    2010-01-11

    We study the sensitivity of weak lensing surveys to the effects of catastrophic redshift errors - cases where the true redshift is misestimated by a significant amount. To compute the biases in cosmological parameters, we adopt an efficient linearized analysis where the redshift errors are directly related to shifts in the weak lensing convergence power spectra. We estimate the number Nspec of unbiased spectroscopic redshifts needed to determine the catastrophic error rate well enough that biases in cosmological parameters are below statistical errors of weak lensing tomography. While the straightforward estimate of Nspec is ~106 we find that using onlymore » the photometric redshifts with z ≤ 2.5 leads to a drastic reduction in Nspec to ~ 30,000 while negligibly increasing statistical errors in dark energy parameters. Therefore, the size of spectroscopic survey needed to control catastrophic errors is similar to that previously deemed necessary to constrain the core of the zs – zp distribution. We also study the efficacy of the recent proposal to measure redshift errors by cross-correlation between the photo-z and spectroscopic samples. We find that this method requires ~ 10% a priori knowledge of the bias and stochasticity of the outlier population, and is also easily confounded by lensing magnification bias. In conclusion, the cross-correlation method is therefore unlikely to supplant the need for a complete spectroscopic redshift survey of the source population.« less

  12. Harmonic and interharmonic distortion modeling in multiconverter systems

    SciTech Connect (OSTI)

    Carbone, R.; Morrison, R.E.; Testa, A.; Menniti, D.

    1995-07-01

    The problem of modeling multiconverter systems in presence of harmonic and interharmonic distortion is considered. Specifically, current source rectifiers are considered as distortion sources some supply d.c. motors and the remaining supplying inverters feeding a.c. machines. The classical analogue, frequency domain and time domain models proposed in the literature to study harmonic distortion in a multiconverter system are considered and for each model suitable extension to include the interharmonic distortion are presented and critically analyzed. The results of several experiments are reported to show the usefulness and to compare the accuracy of the different extensions considered.

  13. COMPARING DENSE GALAXY CLUSTER REDSHIFT SURVEYS WITH WEAK-LENSING MAPS

    SciTech Connect (OSTI)

    Hwang, Ho Seong; Geller, Margaret J.; Zahid, H. Jabran; Diaferio, Antonaldo; Rines, Kenneth J. E-mail: mgeller@cfa.harvard.edu E-mail: diaferio@ph.unito.it

    2014-12-20

    We use dense redshift surveys of nine galaxy clusters at z ∼ 0.2 to compare the galaxy distribution in each system with the projected matter distribution from weak lensing. By combining 2087 new MMT/Hectospec redshifts and the data in the literature, we construct spectroscopic samples within the region of weak-lensing maps of high (70%-89%) and uniform completeness. With these dense redshift surveys, we construct galaxy number density maps using several galaxy subsamples. The shape of the main cluster concentration in the weak-lensing maps is similar to the global morphology of the number density maps based on cluster members alone, mainly dominated by red members. We cross-correlate the galaxy number density maps with the weak-lensing maps. The cross-correlation signal when we include foreground and background galaxies at 0.5z {sub cl} < z < 2z {sub cl} is 10%-23% larger than for cluster members alone at the cluster virial radius. The excess can be as high as 30% depending on the cluster. Cross-correlating the galaxy number density and weak-lensing maps suggests that superimposed structures close to the cluster in redshift space contribute more significantly to the excess cross-correlation signal than unrelated large-scale structure along the line of sight. Interestingly, the weak-lensing mass profiles are not well constrained for the clusters with the largest cross-correlation signal excesses (>20% for A383, A689, and A750). The fractional excess in the cross-correlation signal including foreground and background structures could be a useful proxy for assessing the reliability of weak-lensing cluster mass estimates.

  14. Bulgeless galaxies at intermediate redshift: Sample selection, color properties, and the existence of powerful active galactic nuclei

    SciTech Connect (OSTI)

    Bizzocchi, Luca; Leonardo, Elvira; Grossi, Marco; Afonso, Jos; Fernandes, Cristina; Retr, Joo; Filho, Mercedes E.; Lobo, Catarina; Griffith, Roger L.; Anton, Sonia; Bell, Eric F.; Brinchmann, Jarle; Henriques, Bruno; Messias, Hugo

    2014-02-10

    We present a catalog of bulgeless galaxies, which includes 19,225 objects selected in four of the deepest, largest multi-wavelength data sets availableCOSMOS, AEGIS, GEMS, and GOODSat intermediate redshift (0.4 ? z ? 1.0). The morphological classification was provided by the Advanced Camera for Surveys General Catalog (ACS-GC), which used publicly available data obtained with the ACS instrument on the Hubble Space Telescope. Rest-frame photometric quantities were derived using kcorrect. We analyze the properties of the sample and the evolution of pure-disk systems with redshift. Very massive [log (M {sub *}/M {sub ?}) > 10.5] bulgeless galaxies contribute to ?30% of the total galaxy population number density at z ? 0.7, but their number density drops substantially with decreasing redshift. We show that only a negligible fraction of pure disks appear to be quiescent systems, and red sequence bulgeless galaxies show indications of dust-obscured star formation. X-ray catalogs were used to search for X-ray emission within our sample. After visual inspection and detailed parametric morphological fitting we identify 30 active galactic nuclei (AGNs) that reside in galaxies without a classical bulge. The finding of such peculiar objects at intermediate redshift shows that while AGN growth in merger-free systems is a rare event (0.2% AGN hosts in this sample of bulgeless galaxies), it can indeed happen relatively early in the history of the universe.

  15. Flow Distortion Study Completed for the Chesapeake Light Tower...

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

    With the completion of a flow distortion study, a first stage-gate has been passed in the ... for resource assessment and to support research and development to advance offshore wind ...

  16. Overcoming residual stresses and machining distortion in the production of

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

    aluminum alloy satellite boxes. (Technical Report) | SciTech Connect Overcoming residual stresses and machining distortion in the production of aluminum alloy satellite boxes. Citation Details In-Document Search Title: Overcoming residual stresses and machining distortion in the production of aluminum alloy satellite boxes. × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information

  17. Ultra-lightweight telescope with MEMS adaptive optic for distortion

    Office of Scientific and Technical Information (OSTI)

    correction. (Technical Report) | SciTech Connect Technical Report: Ultra-lightweight telescope with MEMS adaptive optic for distortion correction. Citation Details In-Document Search Title: Ultra-lightweight telescope with MEMS adaptive optic for distortion correction. Recent world events have underscored the need for a satellite based persistent global surveillance capability. To be useful, the satellite must be able to continuously monitor objects the size of a person anywhere on the globe

  18. Ultra-lightweight telescope with MEMS adaptive optic for distortion

    Office of Scientific and Technical Information (OSTI)

    correction. (Technical Report) | SciTech Connect Ultra-lightweight telescope with MEMS adaptive optic for distortion correction. Citation Details In-Document Search Title: Ultra-lightweight telescope with MEMS adaptive optic for distortion correction. × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional

  19. HERSCHEL OBSERVATIONS OF FAR-INFRARED COOLING LINES IN INTERMEDIATE REDSHIFT (ULTRA)-LUMINOUS INFRARED GALAXIES

    SciTech Connect (OSTI)

    Rigopoulou, D.; Magdis, G. E.; Thatte, N.; Hopwood, R.; Clements, D.; Swinyard, B. M.; Pearson, C.; Farrah, D.; Huang, J.-S.; Alonso-Herrero, A.; Bock, J. J.; Cooray, A.; Griffin, M. J.; Oliver, S.; Smith, A.; Wang, L.; Riechers, D.; Scott, D.; Vaccari, M.; Valtchanov, I.

    2014-01-20

    We report the first results from a spectroscopic survey of the [C II] 158?m line from a sample of intermediate redshift (0.2 10{sup 11.5} L {sub ?}), using the Spectral and Photometric Imaging REceiver-Fourier Transform Spectrometer on board the Herschel Space Observatory. This is the first survey of [C II] emission, an important tracer of star formation, at a redshift range where the star formation rate density of the universe increases rapidly. We detect strong [C II] 158?m line emission from over 80% of the sample. We find that the [C II] line is luminous, in the range (0.8-4) 10{sup 3} of the far-infrared continuum luminosity of our sources, and appears to arise from photodissociation regions on the surface of molecular clouds. The L{sub [C} {sub II]}/L {sub IR} ratio in our intermediate redshift (U)LIRGs is on average ?10times larger than that of local ULIRGs. Furthermore, we find that the L{sub [C} {sub II]}/L {sub IR} and L{sub [CII]}/L{sub CO(1-0)} ratios in our sample are similar to those of local normal galaxies and high-z star-forming galaxies. ULIRGs at z ? 0.5 show many similarities to the properties of local normal and high-z star-forming galaxies. Our findings strongly suggest that rapid evolution in the properties of the star-forming regions of (U)LIRGs is likely to have occurred in the last 5 billion years.

  20. THE SPITZER HIGH-REDSHIFT RADIO GALAXY SURVEY

    SciTech Connect (OSTI)

    De Breuck, Carlos; Galametz, Audrey; Vernet, Joel; Seymour, Nick; Stern, Daniel; Eisenhardt, P. R. M.; Willner, S. P.; Fazio, G. G.; Lacy, Mark; Rettura, Alessandro; Rocca-Volmerange, Brigitte

    2010-12-10

    We present results from a comprehensive imaging survey of 70 radio galaxies at redshifts 1 < z < 5.2 using all three cameras on board the Spitzer Space Telescope. The resulting spectral energy distributions unambiguously show a stellar population in 46 sources and hot dust emission associated with the active nucleus in 59. Using a new rest-frame S{sub 3{sub {mu}m}}/S{sub 1.6{sub {mu}m}} versus S{sub 5{sub {mu}m}}/S{sub 3{sub {mu}m}} criterion, we identify 42 sources where the rest-frame 1.6 {mu}m emission from the stellar population can be measured. For these radio galaxies, the median stellar mass is high, 2 x 10{sup 11} M{sub sun}, and remarkably constant within the range 1 < z < 3. At z>3, there is tentative evidence for a factor of two decrease in stellar mass. This suggests that radio galaxies have assembled the bulk of their stellar mass by z {approx} 3, but confirmation by more detailed decomposition of stellar and active galactic nucleus (AGN) emission is needed. The rest-frame 500 MHz radio luminosities are only marginally correlated with stellar mass but are strongly correlated with the rest-frame 5 {mu}m hot dust luminosity. This suggests that the radio galaxies have a large range of Eddington ratios. We also present new Very Large Array 4.86 and 8.46 GHz imaging of 14 radio galaxies and find that radio core dominance-an indicator of jet orientation-is strongly correlated with hot dust luminosity. While all of our targets were selected as narrow-lined, type 2 AGNs, this result can be understood in the context of orientation-dependent models if there is a continuous distribution of orientations from obscured type 2 to unobscured type 1 AGNs rather than a clear dichotomy. Finally, four radio galaxies have nearby (<6'') companions whose mid-IR colors are suggestive of their being AGNs. This may indicate an association between radio galaxy activity and major mergers.

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

    SciTech Connect (OSTI)

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

    2014-07-01

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

  2. ULTRAVIOLET SPECTROSCOPY OF RAPIDLY ROTATING SOLAR-MASS STARS: EMISSION-LINE REDSHIFTS AS A TEST OF THE SOLAR-STELLAR CONNECTION

    SciTech Connect (OSTI)

    Linsky, Jeffrey L.; Bushinsky, Rachel; Ayres, Tom; France, Kevin

    2012-07-20

    We compare high-resolution ultraviolet spectra of the Sun and thirteen solar-mass main-sequence stars with different rotational periods that serve as proxies for their different ages and magnetic field structures. In this, the second paper in the series, we study the dependence of ultraviolet emission-line centroid velocities on stellar rotation period, as rotation rates decrease from that of the Pleiades star HII314 (P{sub rot} = 1.47 days) to {alpha} Cen A (P{sub rot} = 28 days). Our stellar sample of F9 V to G5 V stars consists of six stars observed with the Cosmic Origins Spectrograph on the Hubble Space Telescope (HST) and eight stars observed with the Space Telescope Imaging Spectrograph on HST. We find a systematic trend of increasing redshift with more rapid rotation (decreasing rotation period) that is similar to the increase in line redshift between quiet and plage regions on the Sun. The fastest-rotating solar-mass star in our study, HII314, shows significantly enhanced redshifts at all temperatures above log T = 4.6, including the corona, which is very different from the redshift pattern observed in the more slowly rotating stars. This difference in the redshift pattern suggests that a qualitative change in the magnetic-heating process occurs near P{sub rot} = 2 days. We propose that HII314 is an example of a solar-mass star with a magnetic heating rate too large for the physical processes responsible for the redshift pattern to operate in the same way as for the more slowly rotating stars. HII314 may therefore lie above the high activity end of the set of solar-like phenomena that is often called the 'solar-stellar connection'.

  3. Identifying high-redshift gamma-ray bursts with RATIR

    SciTech Connect (OSTI)

    Littlejohns, O. M.; Butler, N. R. [School of Earth and Space Exploration, Arizona State University, AZ 85287 (United States); Cucchiara, A. [Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Watson, A. M.; Lee, W. H.; Richer, M. G.; De Diego, J. A.; Georgiev, L.; Gonzlez, J.; Romn-Ziga, C. G. [Instituto de Astronoma, Universidad Nacional Autnoma de Mxico, Apartado Postal 70-264, 04510 Mxico, D. F. (Mexico); Kutyrev, A. S.; Troja, E.; Gehrels, N.; Moseley, H. [NASA, Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Klein, C. R.; Fox, O. D.; Bloom, J. S. [Astronomy Department, University of California, Berkeley, CA 94720-7450 (United States); Prochaska, J. X.; Ramirez-Ruiz, E. [Department of Astronomy and Astrophysics, UCO/Lick Observatory, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States)

    2014-07-01

    We present a template-fitting algorithm for determining photometric redshifts, z {sub phot}, of candidate high-redshift gamma-ray bursts (GRBs). Using afterglow photometry, obtained by the Reionization and Transients InfraRed (RATIR) camera, this algorithm accounts for the intrinsic GRB afterglow spectral energy distribution, host dust extinction, and the effect of neutral hydrogen (local and cosmological) along the line of sight. We present the results obtained by this algorithm and the RATIR photometry of GRB 130606A, finding a range of best-fit solutions, 5.6 < z {sub phot} < 6.0, for models of several host dust extinction laws (none, the Milky Way, Large Magellanic Clouds, and Small Magellanic Clouds), consistent with spectroscopic measurements of the redshift of this GRB. Using simulated RATIR photometry, we find that our algorithm provides precise measures of z {sub phot} in the ranges of 4 < z {sub phot} ? 8 and 9 < z {sub phot} < 10 and can robustly determine when z {sub phot} > 4. Further testing highlights the required caution in cases of highly dust-extincted host galaxies. These tests also show that our algorithm does not erroneously find z {sub phot} < 4 when z {sub sim} > 4, thereby minimizing false negatives and allowing us to rapidly identify all potential high-redshift events.

  4. EVOLUTION OF GALAXY LUMINOSITY FUNCTION USING PHOTOMETRIC REDSHIFTS

    SciTech Connect (OSTI)

    Ramos, B. H. F.; Pellegrini, P. S.; Da Costa, L. N.; Maia, M. A. G.; Ogando, R. L. C.; De Simoni, F.; Benoist, C.; Makler, M.; Mesquita, A. A. E-mail: pssp@linea.gov.br E-mail: maia@linea.gov.br E-mail: fsimoni@linea.gov.br E-mail: martin@cbpf.br

    2011-08-15

    We examine the impact of using photometric redshifts for studying the evolution of both the global galaxy luminosity function (LF) and that for different galaxy types. To this end, we compare the LFs obtained using photometric redshifts from the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) D1 field with those from the spectroscopic survey VIMOS VLT Deep Survey (VVDS) comprising {approx}4800 galaxies. We find that for z {<=} 2.0, in the interval of magnitudes considered by this survey, the LFs obtained using photometric and spectroscopic redshifts show a remarkable agreement. This good agreement led us to use all four Deep fields of the CFHTLS comprising {approx}386,000 galaxies to compute the LF of the combined fields and directly estimate the error in the parameters based on the field-to-field variation. We find that the characteristic absolute magnitude M* of Schechter fits fades by {approx}0.7 mag from z {approx} 1.8 to z {approx} 0.3, while the characteristic density {phi}* increases by a factor of {approx}4 in the same redshift interval. We use the galaxy classification provided by the template fitting program used to compute photometric redshifts and split the sample into galaxy types. We find that these Schechter parameters evolve differently for each galaxy type, an indication that their evolution is a combination of several effects: galaxy merging, star formation quenching, and mass assembly. All these results are compatible with those obtained by different spectroscopic surveys such as VVDS, DEEP2, and zCosmos, which reinforces the fact that photometric redshifts can be used to study galaxy evolution, at least for the redshift bins adopted so far. This is of great interest since future very large imaging surveys containing hundreds of millions of galaxies will allow us to obtain important precise measurements to constrain the evolution of the LF and to explore the dependence of this evolution on morphology and/or color helping constrain the mechanisms of galaxy evolution.

  5. A hydrodynamical approach to CMB ?-distortion from primordial perturbations

    SciTech Connect (OSTI)

    Pajer, Enrico; Zaldarriaga, Matias E-mail: matiasz@ias.edu

    2013-02-01

    Spectral distortion of the cosmic microwave background provides a unique opportunity to probe primordial perturbations on very small scales by performing large-scale measurements. We discuss in a systematic and pedagogic way all the relevant physical phenomena involved in the production and evolution of the ?-type spectral distortion. Our main results agree with previous estimates (in particular we show that a recently found factor of 3/4 arises from relativistic corrections to the wave energy). We also discuss several subleading corrections such as adiabatic cooling and the effects of bulk viscosity, baryon loading and photon heat conduction. Finally we provide formulae for the spatial dependence of ?-distortions and its transfer function between the end of the ?-era and now.

  6. Low thermal distortion Extreme-UV lithography reticle and method

    DOE Patents [OSTI]

    Gianoulakis, Steven E. (Albuquerque, NM); Ray-Chaudhuri, Avijit K. (Livermore, CA)

    2002-01-01

    Thermal distortion of reticles or masks can be significantly reduced by emissivity engineering, i.e., the selective placement or omission of coatings on the reticle. Reflective reticles so fabricated exhibit enhanced heat transfer thereby reducing the level of thermal distortion and ultimately improving the quality of the transcription of the reticle pattern onto the wafer. Reflective reticles include a substrate having an active region that defines the mask pattern and non-active region(s) that are characterized by a surface that has a higher emissivity than that of the active region. The non-active regions are not coated with the radiation reflective material.

  7. Low thermal distortion extreme-UV lithography reticle

    DOE Patents [OSTI]

    Gianoulakis, Steven E. (Albuquerque, NM); Ray-Chaudhuri, Avijit K. (Livermore, CA)

    2002-01-01

    Thermal distortion of reticles or masks can be significantly reduced by emissivity engineering, i.e., the selective placement or omission of coatings on the reticle. Reflective reticles so fabricated exhibit enhanced heat transfer thereby reducing the level of thermal distortion and ultimately improving the quality of the transcription of the reticle pattern onto the wafer. Reflective reticles include a substrate having an active region that defines the mask pattern and non-active region(s) that are characterized by a surface that has a higher emissivity than that of the active region. The non-active regions are not coated with the radiation reflective material.

  8. Low thermal distortion extreme-UV lithography reticle

    DOE Patents [OSTI]

    Gianoulakis, Steven E. (Albuquerque, NM); Ray-Chaudhuri, Avijit K. (Livermore, CA)

    2001-01-01

    Thermal distortion of reticles or masks can be significantly reduced by emissivity engineering, i.e., the selective placement or omission of coatings on the reticle. Reflective reticles so fabricated exhibit enhanced heat transfer thereby reducing the level of thermal distortion and ultimately improving the quality of the transcription of the reticle pattern onto the wafer. Reflective reticles include a substrate having an active region that defines the mask pattern and non-active region(s) that are characterized by a surface that has a higher emissivity than that of the active region. The non-active regions are not coated with the radiation reflective material.

  9. Spatial density fluctuations and selection effects in galaxy redshift surveys

    SciTech Connect (OSTI)

    Labini, Francesco Sylos; Tekhanovich, Daniil; Baryshev, Yurij V. E-mail: d.tekhanovich@spbu.ru

    2014-07-01

    One of the main problems of observational cosmology is to determine the range in which a reliable measurement of galaxy correlations is possible. This corresponds to determining the shape of the correlation function, its possible evolution with redshift and the size and amplitude of large scale structures. Different selection effects, inevitably entering in any observation, introduce important constraints in the measurement of correlations. In the context of galaxy redshift surveys selection effects can be caused by observational techniques and strategies and by implicit assumptions used in the data analysis. Generally all these effects are taken into account by using pair-counting algorithms to measure two-point correlations. We review these methods stressing that they are based on the a-priori assumption that galaxy distribution is spatially homogeneous inside a given sample. We show that, when this assumption is not satisfied by the data, results of the correlation analysis are affected by finite size effects. In order to quantify these effects, we introduce a new method based on the computation of the gradient of galaxy counts along tiny cylinders. We show, by using artificial homogeneous and inhomogeneous point distributions, that this method identifies redshift dependent selection effects and disentangles them from the presence of large scale density fluctuations. We then apply this new method to several redshift catalogs and we find evidence that galaxy distribution, in those samples where selection effects are small enough, is characterized by power-law correlations with exponent ?=0.9 up to 20 Mpc/h followed by a change of slope that, in the range 20100 Mpc/h, corresponds to a power-law exponent ?=0.25. Whether a crossover to spatial uniformity occurs at ?100 Mpc/h or larger scales cannot be clarified by the present data.

  10. System for interferometric distortion measurements that define an optical path

    DOE Patents [OSTI]

    Bokor, Jeffrey; Naulleau, Patrick

    2003-05-06

    An improved phase-shifting point diffraction interferometer can measure both distortion and wavefront aberration. In the preferred embodiment, the interferometer employs an object-plane pinhole array comprising a plurality of object pinholes located between the test optic and the source of electromagnetic radiation and an image-plane mask array that is positioned in the image plane of the test optic. The image-plane mask array comprises a plurality of test windows and corresponding reference pinholes, wherein the positions of the plurality of pinholes in the object-plane pinhole array register with those of the plurality of test windows in image-plane mask array. Electromagnetic radiation that is directed into a first pinhole of object-plane pinhole array thereby creating a first corresponding test beam image on the image-plane mask array. Where distortion is relatively small, it can be directly measured interferometrically by measuring the separation distance between and the orientation of the test beam and reference-beam pinhole and repeating this process for at least one other pinhole of the plurality of pinholes of the object-plane pinhole array. Where the distortion is relative large, it can be measured by using interferometry to direct the stage motion, of a stage supporting the image-plane mask array, and then use the final stage motion as a measure of the distortion.

  11. Confronting X-Ray Emission Models with theHighest-Redshift Kiloparsec-Scale Jets: The z = 3.89 Jet in Quasar 1745+624

    SciTech Connect (OSTI)

    Cheung, C.C.; Stawarz, L.; Siemiginowska, A.; /Harvard-Smithsonian Ctr. Astrophys.

    2006-06-28

    A newly identified kiloparsec-scale X-ray jet in the high-redshift z=3.89 quasar 1745+624 is studied with multi-frequency Very Large Array, Hubble Space Telescope, and Chandra X-ray imaging data. This is only the third large-scale X-ray jet beyond z > 3 known and is further distinguished as being the most luminous relativistic jet observed at any redshift, exceeding 10{sup 45} erg/s in both the radio and X-ray bands. Apart from the jet's extreme redshift, luminosity, and high inferred equipartition magnetic field (in comparison to local analogues), its basic properties such as X-ray/radio morphology and radio polarization are similar to lower-redshift examples. Its resolved linear structure and the convex broad-band spectral energy distributions of three distinct knots are also a common feature among known powerful X-ray jets at lower-redshift. Relativistically beamed inverse Compton and ''non-standard'' synchrotron models have been considered to account for such excess X-ray emission in other jets; both models are applicable to this high-redshift example but with differing requirements for the underlying jet physical properties, such as velocity, energetics, and electron acceleration processes. One potentially very important distinguishing characteristic between the two models is their strongly diverging predictions for the X-ray/radio emission with increasing redshift. This is considered, though with the limited sample of three z > 3 jets it is apparent that future studies targeted at very high-redshift jets are required for further elucidation of this issue. Finally, from the broad-band jet emission we estimate the jet kinetic power to be no less than 10{sup 46} erg/s, which is about 10% of the Eddington luminosity corresponding to this galaxy's central supermassive black hole mass M{sub BH} {approx}> 10{sup 9} M{sub {circle_dot}} estimated here via the virial relation. The optical luminosity of the quasar core is about ten times over Eddington, hence the inferred jet power seems to be much less than that available from mass accretion. The apparent super-Eddington accretion rate may however suggest contribution of the unresolved jet emission to the observed optical flux of the nucleus.

  12. Welding Induced Alignment Distortion in Dual-in-Line LD Packages

    SciTech Connect (OSTI)

    Liu, Wenning N.; Sun, Xin; Khaleel, Mohammad A.; Shi, Frank G.

    2007-11-11

    The tolerance for the movement of a single mode fiber relative to the laser is extremely tight, a submicron movement can often lead to a significant misalignment and thus the reduction in the power coupled into the fiber. Among various fiber pigtailing assembly technologies, pulsed laser welding is the method with submicron accuracy and is most conducive to automation. However, the melting-solidification process during laser welding can often distort the pre-achieved fiber-optic alignment. This Welding-Induced-Alignment-Distortion (WIAD) is a serious concern and significantly affects the yield for single mode fiber pigtailing to a semiconductor laser. In this paper, effect of laser welding sequence on WIAD in a dual-in-line packager is numerically investigated by means of Finite Element Method (FEM). Optimal welding sequence may minimize WIAD in dual-in-line package. Additionally, unsymmetrical space between fiber and U-channel induced by laser welding of U-channelto-plate in DIP LD packages is found to have obvious effect on WIAD.

  13. Superconductivity Distorted by the Coexisting Pseudogap in the Antinodal

    Office of Scientific and Technical Information (OSTI)

    Region of Bi1.5Pb0.55Sr1.6La0.4CuO6+\delta: A Photon-Energy-Dependent Angle-Resolved Photoemission Study (Journal Article) | SciTech Connect Superconductivity Distorted by the Coexisting Pseudogap in the Antinodal Region of Bi1.5Pb0.55Sr1.6La0.4CuO6+\delta: A Photon-Energy-Dependent Angle-Resolved Photoemission Study Citation Details In-Document Search Title: Superconductivity Distorted by the Coexisting Pseudogap in the Antinodal Region of Bi1.5Pb0.55Sr1.6La0.4CuO6+\delta: A

  14. Breast tissue decomposition with spectral distortion correction: A postmortem study

    SciTech Connect (OSTI)

    Ding, Huanjun; Zhao, Bo; Baturin, Pavlo; Behroozi, Farnaz; Molloi, Sabee

    2014-10-15

    Purpose: To investigate the feasibility of an accurate measurement of water, lipid, and protein composition of breast tissue using a photon-counting spectral computed tomography (CT) with spectral distortion corrections. Methods: Thirty-eight postmortem breasts were imaged with a cadmium-zinc-telluride-based photon-counting spectral CT system at 100 kV. The energy-resolving capability of the photon-counting detector was used to separate photons into low and high energy bins with a splitting energy of 42 keV. The estimated mean glandular dose for each breast ranged from 1.8 to 2.2 mGy. Two spectral distortion correction techniques were implemented, respectively, on the raw images to correct the nonlinear detector response due to pulse pileup and charge-sharing artifacts. Dual energy decomposition was then used to characterize each breast in terms of water, lipid, and protein content. In the meantime, the breasts were chemically decomposed into their respective water, lipid, and protein components to provide a gold standard for comparison with dual energy decomposition results. Results: The accuracy of the tissue compositional measurement with spectral CT was determined by comparing to the reference standard from chemical analysis. The averaged root-mean-square error in percentage composition was reduced from 15.5% to 2.8% after spectral distortion corrections. Conclusions: The results indicate that spectral CT can be used to quantify the water, lipid, and protein content in breast tissue. The accuracy of the compositional analysis depends on the applied spectral distortion correction technique.

  15. THE FIRST HIGH-REDSHIFT QUASAR FROM Pan-STARRS

    SciTech Connect (OSTI)

    Morganson, Eric; De Rosa, Gisella; Decarli, Roberto; Walter, Fabian; Rix, Hans-Walter; Chambers, Ken; Burgett, William; Flewelling, Heather; Hodapp, Klaus; Kaiser, Nick; Magnier, Eugene; Sweeney, Bill; Waters, Christopher; McGreer, Ian; Fan, Xiaohui; Greiner, Jochen; Price, Paul

    2012-06-15

    We present the discovery of the first high-redshift (z > 5.7) quasar from the Panoramic Survey Telescope and Rapid Response System 1 (Pan-STARRS1 or PS1). This quasar was initially detected as an i{sub P1} dropout in PS1, confirmed photometrically with the SAO Wide-field InfraRed Camera at Arizona's Multiple Mirror Telescope (MMT) and the Gamma-Ray Burst Optical/Near-Infrared Detector at the MPG 2.2 m telescope in La Silla. The quasar was verified spectroscopically with the MMT Spectrograph, Red Channel and the Cassegrain Twin Spectrograph at the Calar Alto 3.5 m telescope. Its near-infrared spectrum was taken at the Large Binocular Telescope Observatory (LBT) with the LBT Near-Infrared Spectroscopic Utility with Camera and Integral Field Unit for Extragalactic Research. It has a redshift of 5.73, an AB z{sub P1} magnitude of 19.4, a luminosity of 3.8 Multiplication-Sign 10{sup 47} erg s{sup -1}, and a black hole mass of 6.9 Multiplication-Sign 10{sup 9} M{sub Sun }. It is a broad absorption line quasar with a prominent Ly{beta} peak and a very blue continuum spectrum. This quasar is the first result from the PS1 high-redshift quasar search that is projected to discover more than 100 i{sub P1} dropout quasars and could potentially find more than 10 z{sub P1} dropout (z > 6.8) quasars.

  16. Photometric Redshifts for the Dark Energy Survey and VISTA and Implications

    Office of Scientific and Technical Information (OSTI)

    for Large Scale Structure (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Photometric Redshifts for the Dark Energy Survey and VISTA and Implications for Large Scale Structure Citation Details In-Document Search Title: Photometric Redshifts for the Dark Energy Survey and VISTA and Implications for Large Scale Structure We conduct a detailed analysis of the photometric redshift requirements for the proposed Dark Energy Survey (DES) using two sets of mock

  17. Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides

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

    Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print Wednesday, 28 February 2007 00:00 "Ferroelectricity," by analogy to ferromagnetism, is defined as the presence of spontaneous electrical polarization in a material, often arising from distortions in the material's crystal structure. In oxides of the metals lead and bismuth, such distortions were for many years attributed to the existence of

  18. DETERMINING THE LUMINOSITY FUNCTION OF SWIFT LONG GAMMA-RAY BURSTS WITH PSEUDO-REDSHIFTS

    SciTech Connect (OSTI)

    Tan Weiwei; Yu Yunwei [Institute of Astrophysics, Central China Normal University, Wuhan (China); Cao Xiaofeng, E-mail: yuyw@phy.ccnu.edu.cn [School of Physics, Huazhong University of Science and Technology, Wuhan (China)

    2013-07-20

    The determination of the luminosity function (LF) of gamma-ray bursts (GRBs) is an important role for the cosmological applications of the GRBs, which, however, is seriously hindered by some selection effects due to redshift measurements. In order to avoid these selection effects, we suggest calculating pseudo-redshifts for Swift GRBs according to the empirical L-E{sub p} relationship. Here, such a L-E{sub p} relationship is determined by reconciling the distributions of pseudo- and real redshifts of redshift-known GRBs. The values of E{sub p} taken from Butler's GRB catalog are estimated with Bayesian statistics rather than observed. Using the GRB sample with pseudo-redshifts of a relatively large number, we fit the redshift-resolved luminosity distributions of the GRBs with a broken-power-law LF. The fitting results suggest that the LF could evolve with redshift by a redshift-dependent break luminosity, e.g., L{sub b} = 1.2 Multiplication-Sign 10{sup 51}(1 + z){sup 2} erg s{sup -1}. The low- and high-luminosity indices are constrained to 0.8 and 2.0, respectively. It is found that the proportional coefficient between the GRB event rate and the star formation rate should correspondingly decrease with increasing redshifts.

  19. The SDSS Coadd: A Galaxy Photometric Redshift Catalog

    SciTech Connect (OSTI)

    Reis, Ribamar R.R.; Soares-Santos, Marcelle; Annis, James; Dodelson, Scott; Hao, Jiangang; Johnston, David; Kubo, Jeffrey; Lin, Huan; Seo, Hee-Jong; Simet, Melanie; /Chicago U.

    2011-11-01

    We present and describe a catalog of galaxy photometric redshifts (photo-z's) for the Sloan Digital Sky Survey (SDSS) Coadd Data. We use the Artificial Neural Network (ANN) technique to calculate photo-z's and the Nearest Neighbor Error (NNE) method to estimate photo-z errors for {approx} 13 million objects classified as galaxies in the coadd with r < 24.5. The photo-z and photo-z error estimators are trained and validated on a sample of {approx} 89, 000 galaxies that have SDSS photometry and spectroscopic redshifts measured by the SDSS Data Release 7 (DR7), the Canadian Network for Observational Cosmology Field Galaxy Survey (CNOC2), the Deep Extragalactic Evolutionary Probe Data Release 3(DEEP2 DR3), the SDSS-III's Baryon Oscillation Spectroscopic Survey (BOSS), the Visible imaging Multi-Object Spectrograph - Very Large Telescope Deep Survey (VVDS) and the WiggleZ Dark Energy Survey. For the best ANN methods we have tried, we find that 68% of the galaxies in the validation set have a photo-z error smaller than {sigma}{sub 68} = 0.036. After presenting our results and quality tests, we provide a short guide for users accessing the public data.

  20. One dimensional wavefront distortion sensor comprising a lens array system

    DOE Patents [OSTI]

    Neal, Daniel R. (Tijeras, NM); Michie, Robert B. (Albuquerque, NM)

    1996-01-01

    A 1-dimensional sensor for measuring wavefront distortion of a light beam as a function of time and spatial position includes a lens system which incorporates a linear array of lenses, and a detector system which incorporates a linear array of light detectors positioned from the lens system so that light passing through any of the lenses is focused on at least one of the light detectors. The 1-dimensional sensor determines the slope of the wavefront by location of the detectors illuminated by the light. The 1 dimensional sensor has much greater bandwidth that 2 dimensional systems.

  1. One dimensional wavefront distortion sensor comprising a lens array system

    DOE Patents [OSTI]

    Neal, D.R.; Michie, R.B.

    1996-02-20

    A 1-dimensional sensor for measuring wavefront distortion of a light beam as a function of time and spatial position includes a lens system which incorporates a linear array of lenses, and a detector system which incorporates a linear array of light detectors positioned from the lens system so that light passing through any of the lenses is focused on at least one of the light detectors. The 1-dimensional sensor determines the slope of the wavefront by location of the detectors illuminated by the light. The 1 dimensional sensor has much greater bandwidth that 2 dimensional systems. 8 figs.

  2. Distance-redshift relations in an anisotropic cosmological model

    SciTech Connect (OSTI)

    Menezes, R. S. Jr.; Pigozzo, C.; Carneiro, S. E-mail: cpigozzo@ufba.br

    2013-03-01

    In this paper we study an anisotropic model generated from a particular Bianchi type-III metric, which is a generalization of Gdel's metric and an exact solution of Einstein's field equations. We analyse type Ia supernova data, namely the SDSS sample calibrated with the MLCS2k2 fitter, and we verify in which ranges of distances and redshifts the anisotropy could be observed. We also consider, in a joint analysis, the position of the first peak in the CMB anisotropy spectrum, as well as current observational constraints on the Hubble constant. We conclude that a small anisotropy is permitted by the data, and that more accurate measurements of supernova distances above z = 2 might indicate the existence of such anisotropy in the universe.

  3. RECONSTRUCTING REDSHIFT DISTRIBUTIONS WITH CROSS-CORRELATIONS: TESTS AND AN OPTIMIZED RECIPE

    SciTech Connect (OSTI)

    Matthews, Daniel J.; Newman, Jeffrey A., E-mail: djm70@pitt.ed, E-mail: janewman@pitt.ed [Department of Physics and Astronomy, University of Pittsburgh, 3941 O'Hara Street, Pittsburgh, PA 15260 (United States)

    2010-09-20

    Many of the cosmological tests to be performed by planned dark energy experiments will require extremely well-characterized photometric redshift measurements. Current estimates for cosmic shear are that the true mean redshift of the objects in each photo-z bin must be known to better than 0.002(1 + z), and the width of the bin must be known to {approx}0.003(1 + z) if errors in cosmological measurements are not to be degraded significantly. A conventional approach is to calibrate these photometric redshifts with large sets of spectroscopic redshifts. However, at the depths probed by Stage III surveys (such as DES), let alone Stage IV (LSST, JDEM, and Euclid), existing large redshift samples have all been highly (25%-60%) incomplete, with a strong dependence of success rate on both redshift and galaxy properties. A powerful alternative approach is to exploit the clustering of galaxies to perform photometric redshift calibrations. Measuring the two-point angular cross-correlation between objects in some photometric redshift bin and objects with known spectroscopic redshift, as a function of the spectroscopic z, allows the true redshift distribution of a photometric sample to be reconstructed in detail, even if it includes objects too faint for spectroscopy or if spectroscopic samples are highly incomplete. We test this technique using mock DEEP2 Galaxy Redshift survey light cones constructed from the Millennium Simulation semi-analytic galaxy catalogs. From this realistic test, which incorporates the effects of galaxy bias evolution and cosmic variance, we find that the true redshift distribution of a photometric sample can, in fact, be determined accurately with cross-correlation techniques. We also compare the empirical error in the reconstruction of redshift distributions to previous analytic predictions, finding that additional components must be included in error budgets to match the simulation results. This extra error contribution is small for surveys that sample large areas of sky (>{approx}10{sup 0}-100{sup 0}), but dominant for {approx}1 deg{sup 2} fields. We conclude by presenting a step-by-step, optimized recipe for reconstructing redshift distributions from cross-correlation information using standard correlation measurements.

  4. Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides

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

    Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print "Ferroelectricity," by analogy to ferromagnetism, is defined as the presence of spontaneous electrical polarization in a material, often arising from distortions in the material's crystal structure. In oxides of the metals lead and bismuth, such distortions were for many years attributed to the existence of "lone pair" electrons: pairs of chemically inert, nonbonding valence electrons in hybrid orbitals

  5. Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides

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

    Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print "Ferroelectricity," by analogy to ferromagnetism, is defined as the presence of spontaneous electrical polarization in a material, often arising from distortions in the material's crystal structure. In oxides of the metals lead and bismuth, such distortions were for many years attributed to the existence of "lone pair" electrons: pairs of chemically inert, nonbonding valence electrons in hybrid orbitals

  6. Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides

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

    Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides Print "Ferroelectricity," by analogy to ferromagnetism, is defined as the presence of spontaneous electrical polarization in a material, often arising from distortions in the material's crystal structure. In oxides of the metals lead and bismuth, such distortions were for many years attributed to the existence of "lone pair" electrons: pairs of chemically inert, nonbonding valence electrons in hybrid orbitals

  7. LUMINOSITY DISTRIBUTION OF GAMMA-RAY BURST HOST GALAXIES AT REDSHIFT...

    Office of Scientific and Technical Information (OSTI)

    LUMINOSITY DISTRIBUTION OF GAMMA-RAY BURST HOST GALAXIES AT REDSHIFT z 1 IN COSMOLOGICAL ... Citation Details In-Document Search Title: LUMINOSITY DISTRIBUTION OF GAMMA-RAY BURST HOST ...

  8. Estimating luminosities and stellar masses of galaxies photometrically without determining redshifts

    SciTech Connect (OSTI)

    Hsieh, B. C.; Yee, H. K. C. E-mail: hyee@astro.utoronto.ca

    2014-09-10

    Large direct imaging surveys usually use a template-fitting technique to estimate photometric redshifts for galaxies, which are then applied to derive important galaxy properties such as luminosities and stellar masses. These estimates can be noisy and suffer from systematic biases because of the possible mis-selection of templates and the propagation of the photometric redshift uncertainty. We introduce an algorithm, the Direct Empirical Photometric method (DEmP), that can be used to directly estimate these quantities using training sets, bypassing photometric redshift determination. DEmP also applies two techniques to minimize the effects arising from the non-uniform distribution of training set galaxy redshifts from a flux-limited sample. First, for each input galaxy, fitting is performed using a subset of the training set galaxies with photometry and colors closest to those of the input galaxy. Second, the training set is artificially resampled to produce a flat distribution in redshift or other properties, e.g., luminosity. To test the performance of DEmP, we use a four filter-band mock catalog to examine its ability to recover redshift, luminosity, stellar mass, and luminosity and stellar mass functions. We also compare the results to those from two publicly available template-fitting methods, finding that the DEmP algorithm outperforms both. We find that resampling the training set to have a uniform redshift distribution produces the best results not only in photometric redshift, but also in estimating luminosity and stellar mass. The DEmP method is especially powerful in estimating quantities such as near-IR luminosities and stellar mass using only data from a small number of optical bands.

  9. Gravitational Redshift of Galaxies in Clusters from the Sloan Digital Sky

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

    Survey and the Baryon Oscillation Spectroscopic Survey (Journal Article) | DOE PAGES Gravitational Redshift of Galaxies in Clusters from the Sloan Digital Sky Survey and the Baryon Oscillation Spectroscopic Survey Title: Gravitational Redshift of Galaxies in Clusters from the Sloan Digital Sky Survey and the Baryon Oscillation Spectroscopic Survey Authors: Sadeh, Iftach ; Feng, Low Lerh ; Lahav, Ofer Publication Date: 2015-02-20 OSTI Identifier: 1181622 Type: Publisher's Accepted Manuscript

  10. LUMINOSITY DISTRIBUTION OF GAMMA-RAY BURST HOST GALAXIES AT REDSHIFT z = 1

    Office of Scientific and Technical Information (OSTI)

    IN COSMOLOGICAL SMOOTHED PARTICLE HYDRODYNAMIC SIMULATIONS: IMPLICATIONS FOR THE METALLICITY DEPENDENCE OF GRBs (Journal Article) | SciTech Connect LUMINOSITY DISTRIBUTION OF GAMMA-RAY BURST HOST GALAXIES AT REDSHIFT z = 1 IN COSMOLOGICAL SMOOTHED PARTICLE HYDRODYNAMIC SIMULATIONS: IMPLICATIONS FOR THE METALLICITY DEPENDENCE OF GRBs Citation Details In-Document Search Title: LUMINOSITY DISTRIBUTION OF GAMMA-RAY BURST HOST GALAXIES AT REDSHIFT z = 1 IN COSMOLOGICAL SMOOTHED PARTICLE

  11. Photometric Redshifts for the Dark Energy Survey and VISTA and Implications

    Office of Scientific and Technical Information (OSTI)

    for Large Scale Structure (Journal Article) | SciTech Connect Photometric Redshifts for the Dark Energy Survey and VISTA and Implications for Large Scale Structure Citation Details In-Document Search Title: Photometric Redshifts for the Dark Energy Survey and VISTA and Implications for Large Scale Structure × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is

  12. Gravitational Redshift of Galaxies in Clusters from the Sloan Digital Sky

    Office of Scientific and Technical Information (OSTI)

    Survey and the Baryon Oscillation Spectroscopic Survey (Journal Article) | SciTech Connect Gravitational Redshift of Galaxies in Clusters from the Sloan Digital Sky Survey and the Baryon Oscillation Spectroscopic Survey Citation Details In-Document Search Title: Gravitational Redshift of Galaxies in Clusters from the Sloan Digital Sky Survey and the Baryon Oscillation Spectroscopic Survey Authors: Sadeh, Iftach ; Feng, Low Lerh ; Lahav, Ofer Publication Date: 2015-02-20 OSTI Identifier:

  13. Gravitational Redshift of Galaxies in Clusters from the Sloan Digital Sky

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

    Survey and the Baryon Oscillation Spectroscopic Survey (Journal Article) | SciTech Connect Gravitational Redshift of Galaxies in Clusters from the Sloan Digital Sky Survey and the Baryon Oscillation Spectroscopic Survey Citation Details In-Document Search Title: Gravitational Redshift of Galaxies in Clusters from the Sloan Digital Sky Survey and the Baryon Oscillation Spectroscopic Survey Authors: Sadeh, Iftach ; Feng, Low Lerh ; Lahav, Ofer Publication Date: 2015-02-20 OSTI Identifier:

  14. THE REDSHIFT EVOLUTION OF THE RELATION BETWEEN STELLAR MASS, STAR FORMATION

    Office of Scientific and Technical Information (OSTI)

    RATE, AND GAS METALLICITY OF GALAXIES (Journal Article) | SciTech Connect REDSHIFT EVOLUTION OF THE RELATION BETWEEN STELLAR MASS, STAR FORMATION RATE, AND GAS METALLICITY OF GALAXIES Citation Details In-Document Search Title: THE REDSHIFT EVOLUTION OF THE RELATION BETWEEN STELLAR MASS, STAR FORMATION RATE, AND GAS METALLICITY OF GALAXIES We investigate the relation between stellar mass (M{sub *}), star formation rate (SFR), and metallicity (Z) of galaxies, the so-called fundamental

  15. SHELS: A complete galaxy redshift survey with R ? 20.6

    SciTech Connect (OSTI)

    Geller, Margaret J.; Hwang, Ho Seong; Fabricant, Daniel G.; Kurtz, Michael J.; Dell'Antonio, Ian P.; Zahid, Harus Jabran E-mail: hhwang@cfa.harvard.edu E-mail: mkurtz@cfa.harvard.edu E-mail: jabran@ifa.hawaii.edu

    2014-08-01

    The SHELS (Smithsonian Hectospec Lensing Survey) is a complete redshift survey covering two well-separated fields (F1 and F2) of the Deep Lens Survey to a limiting R = 20.6. Here we describe the redshift survey of the F2 field (R.A.{sub 2000} = 09{sup h}19{sup m}32.4 and decl.{sub 2000} = +3000'00''). The survey includes 16,294 new redshifts measured with the Hectospec on the MMT. The resulting survey of the 4deg{sup 2} F2 field is 95% complete to R = 20.6, currently the densest survey to this magnitude limit. The median survey redshift is z = 0.3; the survey provides a view of structure in the range 0.1 ? z ? 0.6. An animation displays the large-scale structure in the survey region. We provide a redshift, spectral index D {sub n}4000, and stellar mass for each galaxy in the survey. We also provide a metallicity for each galaxy in the range 0.2 redshift. The known evolutionary and stellar mass dependent properties of the galaxy population are cleanly evident in the data. We also show that the mass-metallicity relation previously determined from these data is robust to the analysis approach.

  16. THE MICRO-ARCSECOND SCINTILLATION-INDUCED VARIABILITY (MASIV) SURVEY. III. OPTICAL IDENTIFICATIONS AND NEW REDSHIFTS

    SciTech Connect (OSTI)

    Pursimo, Tapio; Ojha, Roopesh; Rickett, Barney J.; Dutka, Michael S.; Koay, Jun Yi; Bignall, Hayley E.; Macquart, Jean-Pierre; Lovell, James E. J.; Kedziora-Chudczer, Lucyna

    2013-04-10

    Intraday variability (IDV) of the radio emission from active galactic nuclei is now known to be predominantly due to interstellar scintillation (ISS). The MASIV (The Micro-Arcsecond Scintillation-Induced Variability) survey of 443 flat spectrum sources revealed that the IDV is related to the radio flux density and redshift. A study of the physical properties of these sources has been severely handicapped by the absence of reliable redshift measurements for many of these objects. This paper presents 79 new redshifts and a critical evaluation of 233 redshifts obtained from the literature. We classify spectroscopic identifications based on emission line properties, finding that 78% of the sources have broad emission lines and are mainly FSRQs. About 16% are weak lined objects, chiefly BL Lacs, and the remaining 6% are narrow line objects. The gross properties (redshift, spectroscopic class) of the MASIV sample are similar to those of other blazar surveys. However, the extreme compactness implied by ISS favors FSRQs and BL Lacs in the MASIV sample as these are the most compact object classes. We confirm that the level of IDV depends on the 5 GHz flux density for all optical spectral types. We find that BL Lac objects tend to be more variable than broad line quasars. The level of ISS decreases substantially above a redshift of about two. The decrease is found to be generally consistent with ISS expected for beamed emission from a jet that is limited to a fixed maximum brightness temperature in the source rest frame.

  17. Virtually distortion-free imaging system for large field, high resolution lithography

    DOE Patents [OSTI]

    Hawryluk, A.M.; Ceglio, N.M.

    1993-01-05

    Virtually distortion free large field high resolution imaging is performed using an imaging system which contains large field distortion or field curvature. A reticle is imaged in one direction through the optical system to form an encoded mask. The encoded mask is then imaged back through the imaging system onto a wafer positioned at the reticle position.

  18. Epitaxial growth of NiTiO3 with a distorted ilmenite structure

    SciTech Connect (OSTI)

    Varga, Tamas; Droubay, Timothy C.; Bowden, Mark E.; Nachimuthu, Ponnusamy; Shutthanandan, V.; Bolin, Trudy B.; Shelton, William A.; Chambers, Scott A.

    2012-06-30

    MTiO3 (M = Fe, Mn, Ni) compounds have received recent attention as possible candidates for new multiferroic materials capable of magnetization switching by application of an electric field. Epitaxial Ni1-xTi1-yO3 films of different thickness and composition were deposited on Al2O3(0001) by pulsed laser deposition, and characterized using several techniques. Structural parameters for the metastable LiNbO3-type NiTiO3 structure with the space group R3c were predicted using density functional theory calculations, and compared with the experimental results. Our structural data from x-ray diffraction and x-ray absorption spectroscopy indicate that epitaxial ilmenite-type NiTiO3 films were successfully grown. Furthermore, lattice strain exerted by the sapphire substrate results in a distorted ilmenite structure similar to the LiNbO3-type one. Our results demonstrate the potential of oxide heteroepitaxy to stabilize metastable multiferroic phases that may be difficult to prepare or are inaccessible in the bulk.

  19. RUNAWAY STARS AND THE ESCAPE OF IONIZING RADIATION FROM HIGH-REDSHIFT GALAXIES

    SciTech Connect (OSTI)

    Conroy, Charlie; Kratter, Kaitlin M.

    2012-08-20

    Approximately 30% of all massive stars in the Galaxy are runaways with velocities exceeding 30 km s{sup -1}. Their high speeds allow them to travel {approx}0.1-1 kpc away from their birthplace before they explode at the end of their several Myr lifetimes. At high redshift, when galaxies were much smaller than in the local universe, runaways could venture far from the dense inner regions of their host galaxies. From these large radii, and therefore low column densities, much of their ionizing radiation is able to escape into the intergalactic medium. Runaways may therefore significantly enhance the overall escape fraction of ionizing radiation, f{sub esc}, from small galaxies at high redshift. We present simple models of the high-redshift runaway population and its impact on f{sub esc} as a function of halo mass, size, and redshift. We find that the inclusion of runaways enhances f{sub esc} by factors of Almost-Equal-To 1.1-8, depending on halo mass, galaxy geometry, and the mechanism of runaway production, implying that runaways may contribute 50%-90% of the total ionizing radiation escaping from high-redshift galaxies. Runaways may therefore play an important role in reionizing the universe.

  20. Investigation of redshift- and duration-dependent clustering of gamma-ray bursts

    SciTech Connect (OSTI)

    Ukwatta, T. N.; Wo?niak, P. R.

    2015-11-05

    Gamma-ray bursts (GRBs) are detectable out to very large distances and as such are potentially powerful cosmological probes. Historically, the angular distribution of GRBs provided important information about their origin and physical properties. As a general population, GRBs are distributed isotropically across the sky. However, there are published reports that once binned by duration or redshift, GRBs display significant clustering. We have studied the redshift- and duration-dependent clustering of GRBs using proximity measures and kernel density estimation. Utilizing bursts detected by Burst and Transient Source Experiment, Fermi/gamma-ray burst monitor, and Swift/Burst Alert Telescope, we found marginal evidence for clustering in very short duration GRBs lasting less than 100 ms. As a result, our analysis provides little evidence for significant redshift-dependent clustering of GRBs.

  1. Investigation of redshift- and duration-dependent clustering of gamma-ray bursts

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

    Ukwatta, T. N.; Woźniak, P. R.

    2015-11-05

    Gamma-ray bursts (GRBs) are detectable out to very large distances and as such are potentially powerful cosmological probes. Historically, the angular distribution of GRBs provided important information about their origin and physical properties. As a general population, GRBs are distributed isotropically across the sky. However, there are published reports that once binned by duration or redshift, GRBs display significant clustering. We have studied the redshift- and duration-dependent clustering of GRBs using proximity measures and kernel density estimation. Utilizing bursts detected by Burst and Transient Source Experiment, Fermi/gamma-ray burst monitor, and Swift/Burst Alert Telescope, we found marginal evidence for clustering inmore » very short duration GRBs lasting less than 100 ms. As a result, our analysis provides little evidence for significant redshift-dependent clustering of GRBs.« less

  2. Correction of MRI-induced geometric distortions in whole-body...

    Office of Scientific and Technical Information (OSTI)

    Title: Correction of MRI-induced geometric distortions in whole-body small animal PET-MRI Purpose: The fusion of positron emission tomography (PET) and magnetic resonance imaging ...

  3. A restoration model of distorted electron density in wave-cutoff probe measurement

    SciTech Connect (OSTI)

    Jun, Hyun-Su Lee, Yun-Seong

    2014-02-15

    This study investigates the problem of electron density distortion and how the density can be restored in a wave-cutoff probe. Despite recent plasma diagnostics research using a wave-cutoff probe, the problem of electron density distortion caused by plasma conditions has not been resolved. Experimental results indicate that electron density measured using the wave-cutoff method is highly susceptible to variations in the probe tip gap. This electron density distortion is caused by the bulk plasma disturbance between probe tips, and it must be removed for calculating the absolute electron density. To do this, a detailed analytic model was developed using the power balance equation near probe tips. This model demonstrates the characteristics of plasma distortion in wave-cutoff probe measurement and successfully restored the absolute value of electron density with varying probe tip gaps.

  4. DISSECTING PHOTOMETRIC REDSHIFT FOR ACTIVE GALACTIC NUCLEUS USING XMM- AND CHANDRA-COSMOS SAMPLES

    SciTech Connect (OSTI)

    Salvato, M.; Hasinger, G.; Ilbert, O.; Rau, A.; Brusa, M.; Bongiorno, A.; Civano, F.; Elvis, M.; Zamorani, G.; Vignali, C.; Comastri, A.; Bardelli, S.; Bolzonella, M.; Cappelluti, N.; Aussel, H.; Le Floc'h, E.; Mainieri, V.; Capak, P.; Caputi, K.; and others

    2011-12-01

    In this paper, we release accurate photometric redshifts for 1692 counterparts to Chandra sources in the central square degree of the Cosmic Evolution Survey (COSMOS) field. The availability of a large training set of spectroscopic redshifts that extends to faint magnitudes enabled photometric redshifts comparable to the highest quality results presently available for normal galaxies. We demonstrate that morphologically extended, faint X-ray sources without optical variability are more accurately described by a library of normal galaxies (corrected for emission lines) than by active galactic nucleus (AGN) dominated templates, even if these sources have AGN-like X-ray luminosities. Preselecting the library on the bases of the source properties allowed us to reach an accuracy {sigma}{sub {Delta}z/(1+z{sub s{sub p{sub e{sub c)}}}}}{approx}0.015 with a fraction of outliers of 5.8% for the entire Chandra-COSMOS sample. In addition, we release revised photometric redshifts for the 1735 optical counterparts of the XMM-detected sources over the entire 2 deg{sup 2} of COSMOS. For 248 sources, our updated photometric redshift differs from the previous release by {Delta}z > 0.2. These changes are predominantly due to the inclusion of newly available deep H-band photometry (H{sub AB} = 24 mag). We illustrate once again the importance of a spectroscopic training sample and how an assumption about the nature of a source together, with the number and the depth of the available bands, influences the accuracy of the photometric redshifts determined for AGN. These considerations should be kept in mind when defining the observational strategies of upcoming large surveys targeting AGNs, such as eROSITA at X-ray energies and the Australian Square Kilometre Array Pathfinder Evolutionary Map of the Universe in the radio band.

  5. The fate of high redshift massive compact galaxies in dense environments

    SciTech Connect (OSTI)

    Kaufmann, Tobias; Mayer, Lucio; Carollo, Marcella; Feldmann, Robert; /Fermilab /Chicago U., KICP

    2012-01-01

    Massive compact galaxies seem to be more common at high redshift than in the local universe, especially in denser environments. To investigate the fate of such massive galaxies identified at z {approx} 2 we analyse the evolution of their properties in three cosmological hydrodynamical simulations that form virialized galaxy groups of mass {approx} 10{sup 13} M{sub {circle_dot}} hosting a central massive elliptical/S0 galaxy by redshift zero. We find that at redshift {approx} 2 the population of galaxies with M{sub *} > 2 x 10{sup 10} M{sub {circle_dot}} is diverse in terms of mass, velocity dispersion, star formation and effective radius, containing both very compact and relatively extended objects. In each simulation all the compact satellite galaxies have merged into the central galaxy by redshift 0 (with the exception of one simulation where one of such satellite galaxy survives). Satellites of similar mass at z = 0 are all less compact than their high redshift counterparts. They form later than the galaxies in the z = 2 sample and enter the group potential at z < 1, when dynamical friction times are longer than the Hubble time. Also, by z = 0 the central galaxies have increased substantially their characteristic radius via a combination of in situ star formation and mergers. Hence in a group environment descendants of compact galaxies either evolve towards larger sizes or they disappear before the present time as a result of the environment in which they evolve. Since the group-sized halos that we consider are representative of dense environments in the {Lambda}CDM cosmology, we conclude that the majority of high redshift compact massive galaxies do not survive until today as a result of the environment.

  6. Distorted spin dependent spectral function of {sup 3}He and semi-inclusive

    Office of Scientific and Technical Information (OSTI)

    deep inelastic scattering processes (Journal Article) | SciTech Connect Distorted spin dependent spectral function of {sup 3}He and semi-inclusive deep inelastic scattering processes Citation Details In-Document Search Title: Distorted spin dependent spectral function of {sup 3}He and semi-inclusive deep inelastic scattering processes The spin dependent spectral function, relevant to describe polarized electron scattering off polarized {sup 3}He, is studied, within the Plane Wave Impulse

  7. A study of astrometric distortions due to "tree rings" in CCD sensors

    Office of Scientific and Technical Information (OSTI)

    using LSST Photon Simulator (Journal Article) | SciTech Connect A study of astrometric distortions due to "tree rings" in CCD sensors using LSST Photon Simulator Citation Details In-Document Search This content will become publicly available on May 22, 2016 Title: A study of astrometric distortions due to "tree rings" in CCD sensors using LSST Photon Simulator Imperfections in the production process of thick CCDs lead to circularly symmetric dopant concentration

  8. Photon and neutrino redshift in the field of braneworld compact stars

    SciTech Connect (OSTI)

    Hladk, Jan; Stuchlk, Zden?k E-mail: zdenek.stuchlik@fpf.slu.cz

    2011-07-01

    We study gravitational redshift of photons and neutrinos radiated by the braneworld neutron or quark stars that are considered in the framework of the simple model of the internal spacetime with uniform distribution of energy density, and the external spacetime described by the Reissner-Nordstrm geometry characterized by the braneworld ''tidal'' charge b. For negative tidal charges, the external spacetime is of the black-hole type, while for positive tidal charges, the external spacetime can be of both black-hole and naked-singularity type. We consider also extremely compact stars allowing existence of trapped null geodesics in their interior. We assume radiation of photons from the surface at radius R, neutrinos from the whole compact star interior, and their motion along radial null geodesics of the spacetime. In dependency on the compact stars parameters b and R, the photon surface redshift is related to the range of the neutrino internal redshift and the signatures of the tidal charge and possible existence of extremely compact stars are discussed. When both surface (photon) and internal (neutrino) redshift are given by observations, both compact star parameters R and b can be determined in the framework of our simple model.

  9. A SIMPLE TECHNIQUE FOR PREDICTING HIGH-REDSHIFT GALAXY EVOLUTION

    SciTech Connect (OSTI)

    Behroozi, Peter S.; Silk, Joseph

    2015-01-20

    We show that the ratio of galaxies' specific star formation rates (SSFRs) to their host halos' specific mass accretion rates (SMARs) strongly constrains how the galaxies' stellar masses, SSFRs, and host halo masses evolve over cosmic time. This evolutionary constraint provides a simple way to probe z > 8 galaxy populations without direct observations. Tests of the method with galaxy properties at z = 4 successfully reproduce the known evolution of the stellar mass-halo mass (SMHM) relation, galaxy SSFRs, and the cosmic star formation rate (CSFR) for 5 < z < 8. We then predict the continued evolution of these properties for 8 < z < 15. In contrast to the nonevolution in the SMHM relation at z < 4, the median galaxy mass at fixed halo mass increases strongly at z > 4. We show that this result is closely linked to the flattening in galaxy SSFRs at z > 2 compared to halo SMARs; we expect that average galaxy SSFRs at fixed stellar mass will continue their mild evolution to z ? 15. The expected CSFR shows no breaks or features at z > 8.5; this constrains both reionization and the possibility of a steep falloff in the CSFR at z = 9-10. Finally, we make predictions for stellar mass and luminosity functions for the James Webb Space Telescope, which should be able to observe one galaxy with M {sub *} ? 10{sup 8} M {sub ?} per 10{sup 3}Mpc{sup 3} at z = 9.6 and one such galaxy per 10{sup 4}Mpc{sup 3} at z = 15.

  10. Impact of the MLC on the MRI field distortion of a prototype MRI-linac

    SciTech Connect (OSTI)

    Kolling, Stefan; Keall, Paul; Oborn, Brad

    2013-12-15

    Purpose: To cope with intrafraction tumor motion, integrated MRI-linac systems for real-time image guidance are currently under development. The multileaf collimator (MLC) is a key component in every state-of-the-art radiotherapy treatment system, allowing for accurate field shaping and tumor tracking. This work quantifies the magnetic impact of a widely used MLC on the MRI field homogeneity for such a modality.Methods: The finite element method was employed to model a MRI-linac assembly comprised of a 1.0?T split-bore MRI magnet and the key ferromagnetic components of a Varian Millennium 120 MLC, namely, the leaves and motors. Full 3D magnetic field maps of the system were generated. From these field maps, the peak-to-peak distortion within the MRI imaging volume was evaluated over a 30?cm diameter sphere volume (DSV) around the isocenter and compared to a maximum preshim inhomogeneity of 300??T. Five parametric studies were performed: (1) The source-to-isocenter distance (SID) was varied from 100 to 200?cm, to span the range of a compact system to that with lower magnetic coupling. (2) The MLC model was changed from leaves only to leaves with motors, to determine the contribution to the total distortion caused by MLC leaves and motors separately. (3) The system was configured in the inline or perpendicular orientation, i.e., the linac treatment beam was oriented parallel or perpendicular to the magnetic field direction. (4) The treatment field size was varied from 0 0 to 2020?cm{sup 2}, to span the range of clinical treatment fields. (5) The coil currents were scaled linearly to produce magnetic field strengths B{sub 0} of 0.5, 1.0, and 1.5?T, to estimate how the MLC impact changes with B{sub 0}.Results: (1) The MLC-induced MRI field distortion fell continuously with increasing SID. (2) MLC leaves and motors were found to contribute to the distortion in approximately equal measure. (3) Due to faster falloff of the fringe field, the field distortion was generally smaller in the perpendicular beam orientation. The peak-to-peak DSV distortion was below 300??T at SID?130?cm (perpendicular) and SID?140?cm (inline) for the 1.0?T design. (4) The simulation of different treatment fields was identified to cause dynamic changes in the field distribution. However, the estimated residual distortion was below 1.2?mm geometric distortion at SID?120?cm (perpendicular) and SID?130?cm (inline) for a 10?mT/m frequency-encoding gradient. (5) Due to magnetic saturation of the MLC materials, the field distortion remained constant at B{sub 0}>1.0?T.Conclusions: This work shows that the MRI field distortions caused by the MLC cannot be ignored and must be thoroughly investigated for any MRI-linac system. The numeric distortion values obtained for our 1.0?T magnet may vary for other magnet designs with substantially different fringe fields, however the concept of modest increases in the SID to reduce the distortion to a shimmable level is generally applicable.

  11. Correction of MRI-induced geometric distortions in whole-body small animal

    Office of Scientific and Technical Information (OSTI)

    PET-MRI (Journal Article) | SciTech Connect Correction of MRI-induced geometric distortions in whole-body small animal PET-MRI Citation Details In-Document Search Title: Correction of MRI-induced geometric distortions in whole-body small animal PET-MRI Purpose: The fusion of positron emission tomography (PET) and magnetic resonance imaging (MRI) data can be a challenging task in whole-body PET-MRI. The quality of the registration between these two modalities in large field-of-views (FOV) is

  12. High redshift signatures in the 21 cm forest due to cosmic string wakes

    SciTech Connect (OSTI)

    Tashiro, Hiroyuki; Sekiguchi, Toyokazu; Silk, Joseph E-mail: toyokazu.sekiguchi@nagoya-u.jp

    2014-01-01

    Cosmic strings induce minihalo formation in the early universe. The resultant minihalos cluster in string wakes and create a ''21 cm forest'' against the cosmic microwave background (CMB) spectrum. Such a 21 cm forest can contribute to angular fluctuations of redshifted 21 cm signals integrated along the line of sight. We calculate the root-mean-square amplitude of the 21 cm fluctuations due to strings and show that these fluctuations can dominate signals from minihalos due to primordial density fluctuations at high redshift (z?>10), even if the string tension is below the current upper bound, G? < 1.5 10{sup ?7}. Our results also predict that the Square Kilometre Array (SKA) can potentially detect the 21 cm fluctuations due to strings with G? ? 7.5 10{sup ?8} for the single frequency band case and 4.0 10{sup ?8} for the multi-frequency band case.

  13. Confined Space Imager (CSI) Software

    Energy Science and Technology Software Center (OSTI)

    2013-07-03

    The software provides real-time image capture, enhancement, and display, and sensor control for the Confined Space Imager (CSI) sensor system The software captures images over a Cameralink connection and provides the following image enhancements: camera pixel to pixel non-uniformity correction, optical distortion correction, image registration and averaging, and illumination non-uniformity correction. The software communicates with the custom CSI hardware over USB to control sensor parameters and is capable of saving enhanced sensor images to anmore » external USB drive. The software provides sensor control, image capture, enhancement, and display for the CSI sensor system. It is designed to work with the custom hardware.« less

  14. THE EGNoG SURVEY: MOLECULAR GAS IN INTERMEDIATE-REDSHIFT STAR-FORMING GALAXIES

    SciTech Connect (OSTI)

    Bauermeister, A.; Blitz, L.; Wright, M.; Bolatto, A.; Teuben, P.; Bureau, M.; Leroy, A.; Ostriker, E.; Wong, T.

    2013-05-10

    We present the Evolution of molecular Gas in Normal Galaxies (EGNoG) survey, an observational study of molecular gas in 31 star-forming galaxies from z = 0.05 to z = 0.5, with stellar masses of (4-30) Multiplication-Sign 10{sup 10} M{sub Sun} and star formation rates of 4-100 M{sub Sun} yr{sup -1}. This survey probes a relatively un-observed redshift range in which the molecular gas content of galaxies is expected to have evolved significantly. To trace the molecular gas in the EGNoG galaxies, we observe the CO(J = 1 {yields} 0) and CO(J = 3 {yields} 2) rotational lines using the Combined Array for Research in Millimeter-wave Astronomy (CARMA). We detect 24 of 31 galaxies and present resolved maps of 10 galaxies in the lower redshift portion of the survey. We use a bimodal prescription for the CO to molecular gas conversion factor, based on specific star formation rate, and compare the EGNoG galaxies to a large sample of galaxies assembled from the literature. We find an average molecular gas depletion time of 0.76 {+-} 0.54 Gyr for normal galaxies and 0.06 {+-} 0.04 Gyr for starburst galaxies. We calculate an average molecular gas fraction of 7%-20% at the intermediate redshifts probed by the EGNoG survey. By expressing the molecular gas fraction in terms of the specific star formation rate and molecular gas depletion time (using typical values), we also calculate the expected evolution of the molecular gas fraction with redshift. The predicted behavior agrees well with the significant evolution observed from z {approx} 2.5 to today.

  15. Redshift Distributions of Galaxies in the DES Science Verification Shear Catalogue and Implications for Weak Lensing

    SciTech Connect (OSTI)

    Bonnett, C.

    2015-07-21

    We present photometric redshift estimates for galaxies used in the weak lensing analysis of the Dark Energy Survey Science Verification (DES SV) data. Four model- or machine learning-based photometric redshift methods { annz2, bpz calibrated against BCC-U fig simulations, skynet, and tpz { are analysed. For training, calibration, and testing of these methods, we also construct a catalogue of spectroscopically confirmed galaxies matched against DES SV data. The performance of the methods is evalu-ated against the matched spectroscopic catalogue, focusing on metrics relevant for weak lensing analyses, with additional validation against COSMOS photo-zs. From the galaxies in the DES SV shear catalogue, which have mean redshift 0.72 0.01 over the range 0:3 < z < 1:3, we construct three tomographic bins with means of z = {0.45; 0.67,1.00g}. These bins each have systematic uncertainties ?z ? 0.05 in the mean of the fiducial skynet photo-z n(z). We propagate the errors in the redshift distributions through to their impact on cosmological parameters estimated with cosmic shear, and find that they cause shifts in the value of ?8 of approx. 3%. This shift is within the one sigma statistical errors on ?8 for the DES SV shear catalog. We also found that further study of the potential impact of systematic differences on the critical surface density, ?crit, contained levels of bias safely less than the statistical power of DES SV data. We recommend a final Gaussian prior for the photo-z bias in the mean of n(z) of width 0:05 for each of the three tomographic bins, and show that this is a sufficient bias model for the corresponding cosmology analysis.

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

    SciTech Connect (OSTI)

    Inserra, C.; Smartt, S. J., E-mail: c.inserra@qub.ac.uk [Astrophysics Research Centre, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom)

    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 ?M {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.

  17. GRB 120521C at z ? 6 and the properties of high-redshift ?-ray bursts

    SciTech Connect (OSTI)

    Laskar, Tanmoy; Berger, Edo; Zauderer, B. Ashley; Margutti, Raffaella; Fong, Wen-fai [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Tanvir, Nial; Wiersema, Klaas [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Levan, Andrew [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Perley, Daniel [Department of Astronomy, California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Menten, Karl [Max-Planck-Institut fr Radioastronomie, Auf dem Hgel 69, D-53121 Bonn (Germany); Hrudkova, Marie [Isaac Newton Group of Telescopes, Apartado de Correos 321, E-387 00 Santa Cruz de la Palma, Canary Islands (Spain)

    2014-01-20

    We present optical, near-infrared, and radio observations of the afterglow of GRB 120521C. By modeling the multi-wavelength data set, we derive a photometric redshift of z ? 6.0, which we confirm with a low signal-to-noise ratio spectrum of the afterglow. We find that a model with a constant-density environment provides a good fit to the afterglow data, with an inferred density of n ? 0.05 cm{sup 3}. The radio observations reveal the presence of a jet break at t {sub jet} ? 7 d, corresponding to a jet opening angle of ?{sub jet} ? 3. The beaming-corrected ?-ray and kinetic energies are E {sub ?} ? E{sub K} ? 3 10{sup 50} erg. We quantify the uncertainties in our results using a detailed Markov Chain Monte Carlo analysis, which allows us to uncover degeneracies between the physical parameters of the explosion. To compare GRB 120521C to other high-redshift bursts in a uniform manner we re-fit all available afterglow data for the two other bursts at z ? 6 with radio detections (GRBs 050904 and 090423). We find a jet break at t {sub jet} ? 15 d for GRB 090423, in contrast to previous work. Based on these three events, we find that ?-ray bursts (GRBs) at z ? 6 appear to explode in constant-density environments, and exhibit a wide range of energies and densities that span the range inferred for lower redshift bursts. On the other hand, we find a hint for narrower jets in the z ? 6 bursts, potentially indicating a larger true event rate at these redshifts. Overall, our results indicate that long GRBs share a common progenitor population at least to z ? 8.

  18. DUST FORMATION, EVOLUTION, AND OBSCURATION EFFECTS IN THE VERY HIGH-REDSHIFT UNIVERSE

    SciTech Connect (OSTI)

    Dwek, Eli; Benford, Dominic J. [Observational Cosmology Lab., Code 665, NASA at Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Staguhn, Johannes; Su, Ting [Also at Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218, USA. (United States); Arendt, Richard G. [Also at CRESST, University of Maryland Baltimore County, Baltimore, MD 21250, USA. (United States); Kovacks, Attila, E-mail: eli.dwek@nasa.gov [Also at Astronomy Department, CalTech, Pasadena, CA 90025, USA. (United States)

    2014-06-20

    The evolution of dust at redshifts z ? 9, and consequently the dust properties, differs greatly from that in the local universe. In contrast to the local universe, core collapse supernovae (CCSNe) are the only source of thermally condensed dust. Because of the low initial dust-to-gas mass ratio, grain destruction rates are low, so that CCSNe are net producers of interstellar dust. Galaxies with large initial gas mass or high mass infall rate will therefore have a more rapid net rate of dust production compared to galaxies with lower gas mass, even at the same star formation rate. The dust composition is dominated by silicates, which exhibit a strong rise in the UV opacity near the Lyman break. This ''silicate-UV break'' may be confused with the Lyman break, resulting in a misidentification of a galaxy's photometric redshift. In this Letter we demonstrate these effects by analyzing the spectral energy distribution of MACS1149-JD, a lensed galaxy at z = 9.6. A potential 2mm counterpart of MACS1149-JD has been identified with GISMO. While additional observations are required to corroborate this identification, we use this possible association to illustrate the physical processes and the observational effects of dust in the very high-redshift universe.

  19. BRIGHT HOT IMPACTS BY ERUPTED FRAGMENTS FALLING BACK ON THE SUN: UV REDSHIFTS IN STELLAR ACCRETION

    SciTech Connect (OSTI)

    Reale, F.; Orlando, S.; Testa, P.; Landi, E.; Schrijver, C. J.

    2014-12-10

    A solar eruption after a flare on 2011 June 7 produced EUV-bright impacts of fallbacks far from the eruption site, observed with the Solar Dynamics Observatory. These impacts can be taken as a template for the impact of stellar accretion flows. Broad redshifted UV lines have been commonly observed in young accreting stars. Here we study the emission from the impacts in the Atmospheric Imaging Assembly's UV channels and compare the inferred velocity distribution to stellar observations. We model the impacts with two-dimensional hydrodynamic simulations. We find that the localized UV 1600 emission and its timing with respect to the EUV emission can be explained by the impact of a cloud of fragments. The first impacts produce strong initial upflows. The following fragments are hit and shocked by these upflows. The UV emission comes mostly from the shocked front shell of the fragments while they are still falling, and is therefore redshifted when observed from above. The EUV emission instead continues from the hot surface layer that is fed by the impacts. Fragmented accretion can therefore explain broad redshifted UV lines (e.g., C IV 1550 ) to speeds around 400km s{sup 1} observed in accreting young stellar objects.

  20. Simulation of Distortion and Residual Stress Development During Heat Treatment of Steel Castings

    SciTech Connect (OSTI)

    Christoph Beckermann; Kent Carlson

    2011-07-22

    Heat treatment and associated processing, such as quenching, are critical during high strength steel casting production. These processes must be managed closely to prevent thermal and residual stresses that may result in distortion, cracking (particularly after machining), re-work, and weld repair. The risk of casting distortion limits aggressive quenching that can be beneficial to the process and yield an improved outcome. As a result of these distortions, adjustments must be made to the casting or pattern design, or tie bars must be added. Straightening castings after heat treatments can be both time-consuming and expensive. Residual stresses may reduce a casting???¢????????s overall service performance, possibly resulting in catastrophic failure. Stress relieving may help, but expends additional energy in the process. Casting software is very limited in predicting distortions during heat treatment, so corrective measures most often involve a tedious trial-and-error procedure. An extensive review of existing heat treatment residual stress and distortion modeling revealed that it is vital to predict the phase transformations and microstructure of the steel along with the thermal stress development during heat treatment. After reviewing the state-of-the-art in heat treatment residual stress and distortion modeling, an existing commercial code was selected because of its advanced capabilities in predicting phase transformations, the evolving microstructure and related properties along with thermal stress development during heat treatment. However, this software was developed for small parts created from forgings or machined stock, and not for steel castings. Therefore, its predictive capabilities for heat treatment of steel castings were investigated. Available experimental steel casting heat treatment data was determined to be of insufficient detail and breadth, and so new heat treatment experiments were designed and performed, casting and heat treating modified versions of the Navy-C ring (a classical test shape for heat treatment experiments) for several carbon and low alloy steels in order to generate data necessary to validate the code. The predicted distortions were in reasonable agreement with the experimentally measured values. However, the final distortions in the castings were small, making it difficult to determine how accurate the predictions truly are. It is recommended that further validation of the software be performed with the aid of additional experiments with large production steel castings that experience significant heat treatment distortions. It is apparent from this research that the mechanical properties of the bonded sand used for cores and sand molds are key in producing accurate stress simulation results. Because of this, experiments were performed to determine the temperature-dependent elastic modulus of a resin-bonded sand commonly utilized in the steel casting industry. The elastic modulus was seen to vary significantly with heating and cooling rates. Also, the retained room temperature elastic modulus after heating was seen to degrade significantly when the sand was heated above 125???????°C. The elastic modulus curves developed in this work can readily be utilized in casting simulation software. Additional experiments with higher heating rates are recommended to determine the behavior of the elastic modulus in the sand close to the mold-metal interface. The commercial heat treatment residual stress and distortion code, once fully validated, is expected to result in an estimated energy savings of 2.15 trillion BTU???¢????????s/year. Along with these energy savings, reduction of scrap and improvement in casting yield will result in a reduction of the environmental emissions associated with the melting and pouring of the metal which will be saved as a result of this technology.

  1. A far-infrared spectroscopic survey of intermediate redshift (ultra) luminous infrared galaxies

    SciTech Connect (OSTI)

    Magdis, Georgios E.; Rigopoulou, D.; Hopwood, R.; Clements, D.; Huang, J.-S.; Farrah, D.; Pearson, C.; Alonso-Herrero, Almudena; Bock, J. J.; Cooray, A.; Griffin, M. J.; Oliver, S.; Perez Fournon, I.; Riechers, D.; Swinyard, B. M.; Thatte, N.; Scott, D.; Valtchanov, I.; Vaccari, M.

    2014-11-20

    We present Herschel far-IR photometry and spectroscopy as well as ground-based CO observations of an intermediate redshift (0.21 ? z ? 0.88) sample of Herschel-selected (ultra)-luminous infrared galaxies (L {sub IR} > 10{sup 11.5} L {sub ?}). With these measurements, we trace the dust continuum, far-IR atomic line emission, in particular [C II] 157.7 ?m, as well as the molecular gas of z ? 0.3 luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs) and perform a detailed investigation of the interstellar medium of the population. We find that the majority of Herschel-selected intermediate redshift (U)LIRGs have L {sub C} {sub II}/L {sub FIR} ratios that are a factor of about 10 higher than that of local ULIRGs and comparable to that of local normal and high-z star-forming galaxies. Using our sample to bridge local and high-z [C II] observations, we find that the majority of galaxies at all redshifts and all luminosities follow an L {sub C} {sub II}L {sub FIR} relation with a slope of unity, from which local ULIRGs and high- z active-galactic-nucleus-dominated sources are clear outliers. We also confirm that the strong anti-correlation between the L {sub C} {sub II}/L {sub FIR} ratio and the far-IR color L {sub 60}/L {sub 100} observed in the local universe holds over a broad range of redshifts and luminosities, in the sense that warmer sources exhibit lower L {sub C} {sub II}/L {sub FIR} at any epoch. Intermediate redshift ULIRGs are also characterized by large molecular gas reservoirs and by lower star formation efficiencies compared to that of local ULIRGs. The high L {sub C} {sub II}/L {sub FIR} ratios, the moderate star formation efficiencies (L {sub IR}/L{sub CO}{sup ?} or L {sub IR}/M{sub H{sub 2}}), and the relatively low dust temperatures of our sample (which are also common characteristics of high-z star-forming galaxies with ULIRG-like luminosities) indicate that the evolution of the physical properties of (U)LIRGs between the present day and z > 1 is already significant by z ? 0.3.

  2. A REDSHIFT SURVEY OF HERSCHEL FAR-INFRARED SELECTED STARBURSTS AND IMPLICATIONS FOR OBSCURED STAR FORMATION

    SciTech Connect (OSTI)

    Casey, C. M.; Budynkiewicz, J.; Berta, S.; Lutz, D.; Magnelli, B.; Bethermin, M.; Le Floc'h, E.; Magdis, G.; Burgarella, D.; Chapin, E.; Chapman, S. C.; Clements, D. L.; Conley, A.; Conselice, C. J.; Cooray, A.; Farrah, D.; Hatziminaoglou, E.; Ivison, R. J.; and others

    2012-12-20

    We present Keck spectroscopic observations and redshifts for a sample of 767 Herschel-SPIRE selected galaxies (HSGs) at 250, 350, and 500 {mu}m, taken with the Keck I Low Resolution Imaging Spectrometer and the Keck II DEep Imaging Multi-Object Spectrograph. The redshift distribution of these SPIRE sources from the Herschel Multitiered Extragalactic Survey peaks at z = 0.85, with 731 sources at z < 2 and a tail of sources out to z {approx} 5. We measure more significant disagreement between photometric and spectroscopic redshifts (({Delta}z/(1 + z{sub spec})) = 0.29) than is seen in non-infrared selected samples, likely due to enhanced star formation rates and dust obscuration in infrared-selected galaxies. The infrared data are used to directly measure integrated infrared luminosities and dust temperatures independent of radio or 24 {mu}m flux densities. By probing the dust spectral energy distribution (SED) at its peak, we estimate that the vast majority (72%-83%) of z < 2 Herschel-selected galaxies would drop out of traditional submillimeter surveys at 0.85-1 mm. We find that dust temperature traces infrared luminosity, due in part to the SPIRE wavelength selection biases, and partially from physical effects. As a result, we measure no significant trend in SPIRE color with redshift; if dust temperature were independent of luminosity or redshift, a trend in SPIRE color would be expected. Composite infrared SEDs are constructed as a function of infrared luminosity, showing the increase in dust temperature with luminosity, and subtle change in near-infrared and mid-infrared spectral properties. Moderate evolution in the far-infrared (FIR)/radio correlation is measured for this partially radio-selected sample, with q{sub IR}{proportional_to}(1 + z){sup -0.30{+-}0.02} at z < 2. We estimate the luminosity function and implied star formation rate density contribution of HSGs at z < 1.6 and find overall agreement with work based on 24 {mu}m extrapolations of the LIRG, ULIRG, and total infrared contributions. This work significantly increased the number of spectroscopically confirmed infrared-luminous galaxies at z >> 0 and demonstrates the growing importance of dusty starbursts for galaxy evolution studies and the build-up of stellar mass throughout cosmic time.

  3. Galaxy Mergers and Dark Matter Halo Mergers in LCDM: Mass, Redshift, and Mass-Ratio Dependence

    SciTech Connect (OSTI)

    Stewart, Kyle R.; Bullock, James S.; Barton, Elizabeth J.; Wechsler, Risa H.; /KIPAC, Menlo Park /SLAC

    2009-08-03

    We employ a high-resolution LCDM N-body simulation to present merger rate predictions for dark matter halos and investigate how common merger-related observables for galaxies - such as close pair counts, starburst counts, and the morphologically disturbed fraction - likely scale with luminosity, stellar mass, merger mass ratio, and redshift from z = 0 to z = 4. We provide a simple 'universal' fitting formula that describes our derived merger rates for dark matter halos a function of dark halo mass, merger mass ratio, and redshift, and go on to predict galaxy merger rates using number density-matching to associate halos with galaxies. For example, we find that the instantaneous merger rate of m/M > 0.3 mass ratio events into typical L {approx}> fL{sub *} galaxies follows the simple relation dN/dt {approx_equal} 0.03(1+f)Gyr{sup -1} (1+z){sup 2.1}. Despite the rapid increase in merger rate with redshift, only a small fraction of > 0.4L{sub *} high-redshift galaxies ({approx} 3% at z = 2) should have experienced a major merger (m/M > 0.3) in the very recent past (t < 100 Myr). This suggests that short-lived, merger-induced bursts of star formation should not contribute significantly to the global star formation rate at early times, in agreement with observational indications. In contrast, a fairly high fraction ({approx} 20%) of those z = 2 galaxies should have experienced a morphologically transformative merger within a virial dynamical time. We compare our results to observational merger rate estimates from both morphological indicators and pair-fraction based determinations between z = 0-2 and show that they are consistent with our predictions. However, we emphasize that great care must be made in these comparisons because the predicted observables depend very sensitively on galaxy luminosity, redshift, overall mass ratio, and uncertain relaxation timescales for merger remnants. We show that the majority of bright galaxies at z = 3 should have undergone a major merger (> 0.3) in the last 700 Myr and conclude that mergers almost certainly play an important role in delivering baryons and influencing the kinematic properties of Lyman Break Galaxies (LBGs).

  4. InP quantum dots: Electronic structure, surface effects, and the redshifted emission

    SciTech Connect (OSTI)

    Fu, H.; Zunger, A.

    1997-07-01

    We present pseudopotential plane-wave electronic-structure calculations on InP quantum dots in an effort to understand quantum confinement and surface effects and to identify the origin of the long-lived and redshifted luminescence. We find that (i) unlike the case in small GaAs dots, the lowest unoccupied state of InP dots is the {Gamma}{sub 1c}-derived direct state rather than the X{sub 1c}-derived indirect state and (ii) unlike the prediction of {bold k}{center_dot}{bold p} models, the highest occupied state in InP dots has a 1sd-type envelope function rather than a (dipole-forbidden) 1pf envelope function. Thus explanations (i) and (ii) to the long-lived redshifted emission in terms of an orbitally forbidden character can be excluded. Furthermore, (iii) fully passivated InP dots have no surface states in the gap. However, (iv) removal of the anion-site passivation leads to a P dangling bond (DB) state just above the valence band, which will act as a trap for photogenerated holes. Similarly, (v) removal of the cation-site passivation leads to an In dangling-bond state below the conduction band. While the energy of the In DB state depends only weakly on quantum size, its radiative lifetime increases with quantum size. The calculated {approximately}300-meV redshift and the {approximately}18 times longer radiative lifetime relative to the dot-interior transition for the 26-{Angstrom} dot with an In DB are in good agreement with the observations of full-luminescence experiments for unetched InP dots. Yet, (vi) this type of redshift due to surface defect is inconsistent with that measured in {ital selective} excitation for HF-etched InP dots. (vii) The latter type of ({open_quotes}resonant{close_quotes}) redshift is compatible with the calculated {ital screened} singlet-triplet splitting in InP dots, suggesting that the slow emitting state seen in selective excitation could be a triplet state. {copyright} {ital 1997} {ital The American Physical Society}

  5. THE GEOMETRY EFFECTS OF AN EXPANDING UNIVERSE ON THE DETECTION OF COOL NEUTRAL GAS AT HIGH REDSHIFT

    SciTech Connect (OSTI)

    Curran, S. J.

    2012-03-20

    Recent high-redshift surveys for 21 cm absorption in damped Ly{alpha} absorption systems (DLAs) take the number of published searches at z{sub abs} > 2 to 25, the same number as at z{sub abs} < 2, although the detection rate at high redshift remains significantly lower (20% compared to 60%). Using the known properties of the DLAs to estimate the unknown profile widths of the 21 cm non-detections and including the limits via a survival analysis, we show that the mean spin temperature/covering factor degeneracy at high redshift is, on average, double that of the low-redshift sample. This value is significantly lower than the previous factor of eight for the spin temperatures and is about the same factor as in the angular diameter distance ratios between the low- and high-redshift samples. That is, without the need for the several pivotal assumptions, which lead to an evolution in the spin temperature, we show that the observed distribution of 21 cm detections in DLAs can be accounted for by the geometry effects of an expanding universe. That is, as yet there is no evidence of the spin temperature of gas-rich galaxies evolving with redshift.

  6. DIFFUSE FAR-UV LINE EMISSION FROM THE LOW-REDSHIFT LYMAN BREAK GALAXY ANALOG KISSR242

    SciTech Connect (OSTI)

    France, Kevin; Nell, Nicholas; Green, James C. [Center for Astrophysics and Space Astronomy, 389 UCB, University of Colorado, Boulder, CO 80309 (United States); Leitherer, Claus, E-mail: kevin.france@colorado.ed [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2010-10-10

    We present new ultraviolet (UV) observations of the luminous compact blue galaxy KISSR242, obtained with the Hubble Space Telescope-Cosmic Origins Spectrograph (HST-COS). We identify multiple resolved sub-arcsecond near-UV sources within the COS aperture. The far-UV spectroscopic data show strong outflow absorption lines, consistent with feedback processes related to an episode of massive star formation. O I, C II, and Si II-Si IV are observed with a mean outflow velocity (v {sub out}) = -60 km s{sup -1}. We also detect faint fine-structure emission lines of singly ionized silicon for the first time in a low-redshift starburst galaxy. These emissions have been seen previously in deep Lyman break galaxy surveys at z {approx} 3. The Si II* lines are at the galaxy rest velocity, and they exhibit a quantitatively different line profile from the absorption features. These lines have a width of {approx}75 km s{sup -1}, too broad for point-like emission sources such as the H II regions surrounding individual star clusters. The size of the Si II* emitting region is estimated to be {approx}250 pc. We discuss the possibility of this emission arising in overlapping super star cluster H II regions, but find this explanation to be unlikely in light of existing far-UV observations of local star-forming galaxies. We suggest that the observed Si II* emission originates in a diffuse warm halo populated by interstellar gas driven out by intense star formation and/or accreted during a recent interaction that may be fueling the present starburst episode in KISSR242.

  7. dgtoexo2: A Distorted Grid Output File to Exodus II Finite Element Database Conversion Utility

    SciTech Connect (OSTI)

    Moffat, H.K.

    1998-12-01

    This report describes how to obtain publication-quality graphics from distorted grid electronic structure codes using the combination of the conversion utility, dgtoexo2, and mustafa, an AVS Express application. dgtoexo2 converts scalar function results from a format applicable to distorted grid codes into the Exodus II unstructured finite element data representation. nmstafa can read Exodus II files and use the AVS Express engine to visualize data on unix and Windows NT platforms. Though not designed for the purpose, the dgtoexo2/EXOdUS II/mustafa combination is sufficiently versatile to provide for the specialized graphics needs of electronic structure codes. The combination also scales well, producing robust performance for problems involving millions of grid points.

  8. A new reversal mode in exchange coupled antiferromagnetic/ferromagnetic disks: distorted viscous vortex

    SciTech Connect (OSTI)

    Gilbert, Dustin A.; Ye, Li; Varea, Aïda; Agramunt-Puig, Sebastià; del Valle, Nuria; Navau, Carles; López-Barbera, José Francisco; Buchanan, Kristen S.; Hoffmann, Axel; Sánchez, Alvar; Sort, Jordi; Liu, Kai; Nogués, Josep

    2015-04-28

    Magnetic vortices have generated intense interest in recent years due to their unique reversal mechanisms, fascinating topological properties, and exciting potential applications. In addition, the exchange coupling of magnetic vortices to antiferromagnets has also been shown to lead to a range of novel phenomena and functionalities. Here we report a new magnetization reversal mode of magnetic vortices in exchange coupled Ir20Mn80/Fe20Ni80 microdots: distorted viscous vortex reversal. In contrast to the previously known or proposed reversal modes, the vortex is distorted close to the interface and viscously dragged due to the uncompensated spins of a thin antiferromagnet, which leads to unexpected asymmetries in the annihilation and nucleation fields. These results provide a deeper understanding of the physics of exchange coupled vortices and may also have important implications for applications involving exchange coupled nanostructures.

  9. A PARAMETRIC STUDY OF POSSIBLE SOLUTIONS TO THE HIGH-REDSHIFT OVERPRODUCTION OF STARS IN MODELED DWARF GALAXIES

    SciTech Connect (OSTI)

    White, Catherine E.; Somerville, Rachel S.; Ferguson, Henry C.

    2015-02-01

    Both numerical hydrodynamic and semi-analytic cosmological models of galaxy formation struggle to match observed star formation histories of galaxies in low-mass halos (M {sub H} ? 10{sup 11} M {sub ?}), predicting more star formation at high redshift and less star formation at low redshift than observed. The fundamental problem is that galaxies' gas accretion and star formation rates are too closely coupled in the models: the accretion rate largely drives the star formation rate. Observations point to gas accretion rates that outpace star formation at high redshift, resulting in a buildup of gas and a delay in star formation until lower redshifts. We present three empirical adjustments of standard recipes in a semi-analytic model motivated by three physical scenarios that could cause this decoupling: (1) the mass-loading factors of outflows driven by stellar feedback may have a steeper dependence on halo mass at earlier times, (2) the efficiency of star formation may be lower in low-mass halos at high redshift, and (3) gas may not be able to accrete efficiently onto the disk in low-mass halos at high redshift. These new recipes, once tuned, better reproduce the evolution of f {sub *}? M {sub *}/M {sub H} as a function of halo mass as derived from abundance matching over redshifts z = 0 to 3, though they have different effects on cold gas fractions, star formation rates, and metallicities. Changes to gas accretion and stellar-driven winds are promising, while direct modification of the star formation timescale requires drastic measures that are not physically well motivated.

  10. Spectroscopic manifestations of local crystal distortions in excited 4f states in crystals of huntite structure

    SciTech Connect (OSTI)

    Malakhovskii, A. V.; Gnatchenko, S. L.; Kachur, I. S.; Piryatinskaya, V. G.; Sukhachev, A. L.; Sokolov, A. E.; Strokova, A. Ya.; Kartashev, A. V.; Temerov, V. L.

    2013-01-15

    Optical absorption spectra of YbAl{sub 3}(BO{sub 3}){sub 4}, TmAl{sub 3}(BO{sub 3}){sub 4} and TbFe{sub 3}(BO{sub 3}){sub 4} trigonal crystals have been studied in temperature range 2-300 K. Temperature behavior of absorption lines parameters has shown, that during some f-f transitions the local environment of rare earth ions undergo distortions, which are absent in the ground state.

  11. Lattice distortions and oxygen vacancies produced in Au+ irradiated nano-crystalline cubic zirconia

    SciTech Connect (OSTI)

    Edmondson, Philip D; Weber, William J; Namavar, Fereydoon; Zhang, Yanwen

    2011-01-01

    The structural impact of oxygen vacancies in nanocrystalline cubic zirconia is investigated. A non-equilibrium number of oxygen vacancies in introduced to the lattice by ion irradiation. The lattice is observed to be initially compressed, undergoes a relaxation at 0.7 displacements per atom (dpa), and experiences a contraction before reaching a temperature dependent steady state value at above 7 dpa. The level of lattice distortion is related to the charge state of the accumulating oxygen vacancies.

  12. Galaxy Clustering, Photometric Redshifts and Diagnosis of Systematics in the DES Science Verification Data

    SciTech Connect (OSTI)

    Crocce, M.

    2015-12-09

    We study the clustering of galaxies detected at i < 22.5 in the Science Verification observations of the Dark Energy Survey (DES). Two-point correlation functions are measured using 2.3 106 galaxies over a contiguous 116 deg2 region in five bins of photometric redshift width ?z = 0.2 in the range 0.2 < z < 1.2. The impact of photometric redshift errors is assessed by comparing results using a template-based photo-zalgorithm (BPZ) to a machine-learning algorithm (TPZ). A companion paper presents maps of several observational variables (e.g. seeing, sky brightness) which could modulate the galaxy density. Here we characterize and mitigate systematic errors on the measured clustering which arise from these observational variables, in addition to others such as Galactic dust and stellar contamination. After correcting for systematic effects, we then measure galaxy bias over a broad range of linear scales relative to mass clustering predicted from the Planck ? cold dark matter model, finding agreement with the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) measurements with ?2 of 4.0 (8.7) with 5 degrees of freedom for the TPZ (BPZ) redshifts. Furthermore, we test a linear bias model, in which the galaxy clustering is a fixed multiple of the predicted non-linear dark matter clustering. The precision of the data allows us to determine that the linear bias model describes the observed galaxy clustering to 2.5 percent accuracy down to scales at least 410 times smaller than those on which linear theory is expected to be sufficient.

  13. Galaxy Clustering, Photometric Redshifts and Diagnosis of Systematics in the DES Science Verification Data

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

    Crocce, M.

    2015-12-09

    We study the clustering of galaxies detected at i < 22.5 in the Science Verification observations of the Dark Energy Survey (DES). Two-point correlation functions are measured using 2.3 × 106 galaxies over a contiguous 116 deg2 region in five bins of photometric redshift width Δz = 0.2 in the range 0.2 < z < 1.2. The impact of photometric redshift errors is assessed by comparing results using a template-based photo-zalgorithm (BPZ) to a machine-learning algorithm (TPZ). A companion paper presents maps of several observational variables (e.g. seeing, sky brightness) which could modulate the galaxy density. Here we characterize andmore » mitigate systematic errors on the measured clustering which arise from these observational variables, in addition to others such as Galactic dust and stellar contamination. After correcting for systematic effects, we then measure galaxy bias over a broad range of linear scales relative to mass clustering predicted from the Planck Λ cold dark matter model, finding agreement with the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) measurements with χ2 of 4.0 (8.7) with 5 degrees of freedom for the TPZ (BPZ) redshifts. Furthermore, we test a ‘linear bias’ model, in which the galaxy clustering is a fixed multiple of the predicted non-linear dark matter clustering. The precision of the data allows us to determine that the linear bias model describes the observed galaxy clustering to 2.5 percent accuracy down to scales at least 4–10 times smaller than those on which linear theory is expected to be sufficient.« less

  14. Optic for industrial endoscope/borescope with narrow field of view and low distortion

    DOE Patents [OSTI]

    Stone, Gary F.; Trebes, James E.

    2005-08-16

    An optic for the imaging optics on the distal end of a flexible fiberoptic endoscope or rigid borescope inspection tool. The image coverage is over a narrow (<20 degrees) field of view with very low optical distortion (<5% pin cushion or barrel distortion), compared to the typical <20% distortion. The optic will permit non-contact surface roughness measurements using optical techniques. This optic will permit simultaneous collection of selected image plane data, which data can then be subsequently optically processed. The image analysis will yield non-contact surface topology data for inspection where access to the surface does not permit a mechanical styles profilometer verification of surface topology. The optic allows a very broad spectral band or range of optical inspection. It is capable of spectroscopic imaging and fluorescence induced imaging when a scanning illumination source is used. The total viewing angle for this optic is 10 degrees for the full field of view of 10 degrees, compared to 40-70 degrees full angle field of view of the conventional gradient index or GRIN's lens systems.

  15. ON THE KENNICUTT-SCHMIDT RELATION OF LOW-METALLICITY HIGH-REDSHIFT GALAXIES

    SciTech Connect (OSTI)

    Gnedin, Nickolay Y. [Particle Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Kravtsov, Andrey V., E-mail: gnedin@fnal.go, E-mail: andrey@oddjob.uchicago.ed [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States)

    2010-05-01

    We present results of self-consistent, high-resolution cosmological simulations of galaxy formation at z {approx} 3. The simulations employ a recently developed recipe for star formation based on the local abundance of molecular hydrogen, which is tracked self-consistently during the course of simulation. The phenomenological H{sub 2} formation model accounts for the effects of dissociating UV radiation of stars in each galaxy, as well as self-shielding and shielding of H{sub 2} by dust, and therefore allows us to explore effects of lower metallicities and higher UV fluxes prevalent in high-redshift galaxies on their star formation. We compare stellar masses, metallicities, and star formation rates of the simulated galaxies to available observations of the Lyman break galaxies (LBGs) and find a reasonable agreement. We find that the Kennicutt-Schmidt (KS) relation exhibited by our simulated galaxies at z {approx} 3 is substantially steeper and has a lower amplitude than the z = 0 relation at {Sigma}{sub H} {approx_lt} 100 M{sub o-dot} pc{sup -2}. The predicted relation, however, is consistent with existing observational constraints for the z {approx} 3 damped Ly{alpha} and LBGs. Our tests show that the main reason for the difference from the local KS relation is lower metallicity of the interstellar medium in high-redshift galaxies. We discuss several implications of the metallicity-dependence of the KS relation for galaxy evolution and interpretation of observations. In particular, we show that the observed size of high-redshift exponential disks depends sensitively on their KS relation. Our results also suggest that significantly reduced star formation efficiency at low gas surface densities can lead to strong suppression of star formation in low-mass high-redshift galaxies and long gas consumption time scales over most of the disks in large galaxies. The longer gas consumption time scales could make disks more resilient to major and minor mergers and could help explain the prevalence of the thin stellar disks in the local universe.

  16. THE SLOAN DIGITAL SKY SURVEY CO-ADD: A GALAXY PHOTOMETRIC REDSHIFT CATALOG

    SciTech Connect (OSTI)

    Reis, Ribamar R. R.; Soares-Santos, Marcelle; Annis, James; Dodelson, Scott; Hao Jiangang; Johnston, David; Kubo, Jeffrey; Lin Huan; Seo, Hee-Jong; Simet, Melanie

    2012-03-01

    We present and describe a catalog of galaxy photometric redshifts (photo-z) for the Sloan Digital Sky Survey (SDSS) Co-add Data. We use the artificial neural network (ANN) technique to calculate the photo-z and the nearest neighbor error method to estimate photo-z errors for {approx}13 million objects classified as galaxies in the co-add with r < 24.5. The photo-z and photo-z error estimators are trained and validated on a sample of {approx}83,000 galaxies that have SDSS photometry and spectroscopic redshifts measured by the SDSS Data Release 7 (DR7), the Canadian Network for Observational Cosmology Field Galaxy Survey, the Deep Extragalactic Evolutionary Probe Data Release 3, the VIsible imaging Multi-Object Spectrograph-Very Large Telescope Deep Survey, and the WiggleZ Dark Energy Survey. For the best ANN methods we have tried, we find that 68% of the galaxies in the validation set have a photo-z error smaller than {sigma}{sub 68} = 0.031. After presenting our results and quality tests, we provide a short guide for users accessing the public data.

  17. THE MID-INFRARED ENVIRONMENTS OF HIGH-REDSHIFT RADIO GALAXIES

    SciTech Connect (OSTI)

    Galametz, Audrey; Stern, Daniel; De Breuck, Carlos; Vernet, Joeel; Hatch, Nina; Mayo, Jack; Miley, George; Rettura, Alessandro; Seymour, Nick; Adam Stanford, S.

    2012-04-20

    Taking advantage of the impressive sensitivity of Spitzer to detect massive galaxies at high redshift, we study the mid-infrared environments of powerful, high-redshift radio galaxies at 1.2 < z < 3. Galaxy cluster member candidates were isolated using a single Spitzer/IRAC mid-infrared color criterion, [3.6]-[4.5] > -0.1 (AB), in the fields of 48 radio galaxies at 1.2 < z < 3. Using a counts-in-cell analysis, we identify a field as overdense when 15 or more red IRAC sources are found within 1' (i.e., 0.5 Mpc at 1.2 < z < 3) of the radio galaxy to the 5{sigma} flux density limits of our IRAC data (f{sub 4.5} = 13.4 {mu}Jy). We find that radio galaxies lie preferentially in medium to dense regions, with 73% of the targeted fields denser than average. Our (shallow) 120 s data permit the rediscovery of previously known clusters and protoclusters associated with radio galaxies as well as the discovery of new promising galaxy cluster candidates at z > 1.2.

  18. 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.

  19. Virtually distortion-free imaging system for large field, high resolution lithography using electrons, ions or other particle beams

    DOE Patents [OSTI]

    Hawryluk, A.M.; Ceglio, N.M.

    1993-01-12

    Virtually distortion free large field high resolution imaging is performed using an imaging system which contains large field distortion or field curvature. A reticle is imaged in one direction through the optical system to form an encoded mask. The encoded mask is then imaged back through the imaging system onto a wafer positioned at the reticle position. Particle beams, including electrons, ions and neutral particles, may be used as well as electromagnetic radiation.

  20. ULTRA STEEP SPECTRUM RADIO SOURCES IN THE LOCKMAN HOLE: SERVS IDENTIFICATIONS AND REDSHIFT DISTRIBUTION AT THE FAINTEST RADIO FLUXES

    SciTech Connect (OSTI)

    Afonso, J.; Bizzocchi, L.; Grossi, M.; Messias, H.; Fernandes, C. A. C.; Ibar, E.; Ivison, R. J.; Simpson, C.; Chapman, S.; Gonzalez-Solares, E.; Jarvis, M. J.; Rottgering, H.; Norris, R. P.; Dunlop, J.; Best, P.; Pforr, J.; Vaccari, M.; Seymour, N.; Farrah, D.; Huang, J.-S.; and others

    2011-12-20

    Ultra steep spectrum (USS) radio sources have been successfully used to select powerful radio sources at high redshifts (z {approx}> 2). Typically restricted to large-sky surveys and relatively bright radio flux densities, it has gradually become possible to extend the USS search to sub-mJy levels, thanks to the recent appearance of sensitive low-frequency radio facilities. Here a first detailed analysis of the nature of the faintest USS sources is presented. By using Giant Metrewave Radio Telescope and Very Large Array radio observations of the Lockman Hole at 610 MHz and 1.4 GHz, a sample of 58 USS sources, with 610 MHz integrated fluxes above 100 {mu}Jy, is assembled. Deep infrared data at 3.6 and 4.5 {mu}m from the Spitzer Extragalactic Representative Volume Survey (SERVS) are used to reliably identify counterparts for 48 (83%) of these sources, showing an average total magnitude of [3.6]{sub AB} = 19.8 mag. Spectroscopic redshifts for 14 USS sources, together with photometric redshift estimates, improved by the use of the deep SERVS data, for a further 19 objects, show redshifts ranging from z = 0.1 to z = 2.8, peaking at z {approx} 0.6 and tailing off at high redshifts. The remaining 25 USS sources, with no redshift estimate, include the faintest [3.6] magnitudes, with 10 sources undetected at 3.6 and 4.5 {mu}m (typically [3.6] {approx}> 22-23 mag from local measurements), which suggests the likely existence of higher redshifts among the sub-mJy USS population. The comparison with the Square Kilometre Array Design Studies Simulated Skies models indicates that Fanaroff-Riley type I radio sources and radio-quiet active galactic nuclei may constitute the bulk of the faintest USS population, and raises the possibility that the high efficiency of the USS technique for the selection of high-redshift sources remains even at the sub-mJy level.

  1. Size dependence of cubic to trigonal structural distortion in silver micro- and nanocrystals under high pressure

    SciTech Connect (OSTI)

    Guo, Qixum; Zhao, Yusheng; Zin, Zhijun; Wang, Zhongwu; Skrabalak, Sara E; Xia, Younan

    2008-01-01

    Silver micro- and nanocrystals with sizes of {approx}2--3.5 {mu}m and {approx}50--100 nm were uniaxially compressed under nonhydrostatic pressures (strong deviatoric stress) up to {approx}30 GPa at room temperature in a symmetric diamond-anvil cell and studied in situ using angle-dispersive synchrotron X-ray diffraction. A cubic to trigonal structural distortion along a 3-fold rotational axis was discovered by careful and comprehensive analysis of the apparent lattice parameter and full width at half-maximum, which are strongly dependent upon the Miller index and crystal size.

  2. High Average Power Laser Gain Medium With Low Optical Distortion Using A Transverse Flowing Liquid Host

    DOE Patents [OSTI]

    Comaskey, Brian J.; Ault, Earl R.; Kuklo, Thomas C.

    2005-07-05

    A high average power, low optical distortion laser gain media is based on a flowing liquid media. A diode laser pumping device with tailored irradiance excites the laser active atom, ion or molecule within the liquid media. A laser active component of the liquid media exhibits energy storage times longer than or comparable to the thermal optical response time of the liquid. A circulation system that provides a closed loop for mixing and circulating the lasing liquid into and out of the optical cavity includes a pump, a diffuser, and a heat exchanger. A liquid flow gain cell includes flow straighteners and flow channel compression.

  3. REDSHIFT DETERMINATION AND CO LINE EXCITATION MODELING FOR THE MULTIPLY LENSED GALAXY HLSW-01

    SciTech Connect (OSTI)

    Scott, K. S.; Lupu, R. E.; Aguirre, J. E.; Auld, R.; Eales, S.; Aussel, H.; Chanial, P.; Beelen, A.; Bock, J.; Bradford, C. M.; Carpenter, J. M.; Cooray, A.; Dowell, C. D.; Brisbin, D.; Burgarella, D.; Chapman, S. C.; Clements, D. L.; Conley, A.; Cox, P.

    2011-05-20

    We report on the redshift measurement and CO line excitation of HERMES J105751.1+573027 (HLSW-01), a strongly lensed submillimeter galaxy discovered in Herschel/SPIRE observations as part of the Herschel Multi-tiered Extragalactic Survey (HerMES). HLSW-01 is an ultra-luminous galaxy with an intrinsic far-infrared luminosity of L{sub FIR} = 1.4 x 10{sup 13} L{sub sun}, and is lensed by a massive group of galaxies into at least four images with a total magnification of {mu} = 10.9 {+-} 0.7. With the 100 GHz instantaneous bandwidth of the Z-Spec instrument on the Caltech Submillimeter Observatory, we robustly identify a redshift of z = 2.958 {+-} 0.007 for this source, using the simultaneous detection of four CO emission lines (J = 7 {yields} 6, J = 8 {yields} 7, J = 9 {yields} 8, and J = 10 {yields} 9). Combining the measured line fluxes for these high-J transitions with the J = 1 {yields} 0, J = 3 {yields} 2, and J = 5 {yields} 4 line fluxes measured with the Green Bank Telescope, the Combined Array for Research in Millimeter Astronomy, and the Plateau de Bure Interferometer, respectively, we model the physical properties of the molecular gas in this galaxy. We find that the full CO spectral line energy distribution is described well by warm, moderate-density gas with T{sub kin} = 86-235 K and n{sub H{sub 2}} = (1.1-3.5) x 10{sup 3} cm{sup -3}. However, it is possible that the highest-J transitions are tracing a small fraction of very dense gas in molecular cloud cores, and two-component models that include a warm/dense molecular gas phase with T{sub kin} {approx} 200 K, n{sub H{sub 2}}{approx}10{sup 5} cm{sup -3} are also consistent with these data. Higher signal-to-noise measurements of the J{sub up} {>=} 7 transitions with high spectral resolution, combined with high spatial resolution CO maps, are needed to improve our understanding of the gas excitation, morphology, and dynamics of this interesting high-redshift galaxy.

  4. AN EXTREME GRAVITATIONALLY REDSHIFTED IRON LINE AT 4.8 KeV IN Mrk 876

    SciTech Connect (OSTI)

    Bottacini, Eugenio; Orlando, Elena; Moskalenko, Igor [W. W. Hansen Experimental Physics Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, Stanford University (United States); Greiner, Jochen [Max-Planck-Institut fr extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching (Germany); Ajello, Marco [Department of Physics and Astronomy, Clemson University, Clemson, SC 29634-0978 (United States); Persic, Massimo, E-mail: eugenio.bottacini@stanford.edu [INAF-Trieste, via G.B.Tiepolo 11, I-34143 Trieste (Italy)

    2015-01-01

    X-ray spectral lines at unforeseen energies are important because they can shed light on the extreme physical conditions of the environment around the supermassive black holes of active galactic nuclei (AGNs). Mrk 876 displays such a line at 4.80{sub ?0.04}{sup +0.05} rest-frame energy. A possible interpretation of its origin can be found in the hotspot scenario. In this scenario, the primary radiation from a flare in the hot corona of an AGN illuminates a limited portion of the accretion disk that emits by fluorescence. In this context, the line can represent an extreme gravitationally redshifted Fe line originating on the accretion disk below six gravitational radii from a rotating supermassive black hole. The correct estimate of the line significance requires a dedicated approach. Based on an existing rigorous approach, we have performed extensive Monte Carlo simulations. We determine that the line is a real feature at a ?99% confidence level.

  5. Lyalpha RADIATIVE TRANSFER WITH DUST: ESCAPE FRACTIONS FROM SIMULATED HIGH-REDSHIFT GALAXIES

    SciTech Connect (OSTI)

    Laursen, Peter; Sommer-Larsen, Jesper; Andersen, Anja C. E-mail: jslarsen@astro.ku.d

    2009-10-20

    The Lyalpha emission line is an essential diagnostic tool for probing galaxy formation and evolution. Not only is it commonly the strongest observable line from high-redshift galaxies, but from its shape detailed information about its host galaxy can be revealed. However, due to the scattering nature of Lyalpha photons increasing their path length in a nontrivial way, if dust is present in the galaxy, the line may be severely suppressed and its shape altered. In order to interpret observations correctly, it is thus of crucial significance to know how much of the emitted light actually escapes the galaxy. In the present work, using a combination of high-resolution cosmological hydrosimulations and an adaptively refinable Monte Carlo Lyalpha radiative transfer code including an environment dependent model of dust, the escape fractions f {sub esc} of Lyalpha radiation from high-redshift (z = 3.6) galaxies are calculated. In addition to the average escape fraction, the variation of f {sub esc} in different directions and from different parts of the galaxies is investigated, as well as the effect on the emergent spectrum. Escape fractions from a sample of simulated galaxies of representative physical properties are found to decrease for increasing galaxy virial mass M {sub vir}, from f {sub esc} approaching unity for M {sub vir} approx 10{sup 9} M {sub sun} to f {sub esc} less than 10% for M {sub vir} approx 10{sup 12} M {sub sun}. In spite of dust being almost gray, it is found that the emergent spectrum is affected nonuniformly, with the escape fraction of photons close to the line center being much higher than of those in the wings, thus effectively narrowing the Lyalpha line.

  6. The highest redshift quasar at z = 7.085: A radio-quiet source

    SciTech Connect (OSTI)

    Momjian, E.; Carilli, C. L.; Walter, F.; Venemans, B. E-mail: ccarilli@nrao.edu E-mail: venemans@mpia.de

    2014-01-01

    We present 1-2 GHz Very Large Array A-configuration continuum observations on the highest redshift quasar known to date, the z = 7.085 quasar ULAS J112001.48+064124.3. The results show no radio continuum emission at the optical position of the quasar or its vicinity at a level of ?3? or 23.1 ?Jy beam{sup 1}. This 3? limit corresponds to a rest-frame 1.4 GHz luminosity density limit of L {sub ?,} {sub 1.4} {sub GHz} < 1.76 10{sup 24} W Hz{sup 1} for a spectral index of ? = 0, and L {sub ?,} {sub 1.4} {sub GHz} < 1.42 10{sup 25} W Hz{sup 1} for a spectral index of ? = 1. The rest-frame 1.4 GHz luminosity limits are L {sub rad} < 6.43 10{sup 6} L {sub ?} and L {sub rad} < 5.20 10{sup 7} L {sub ?} for ? = 0 and ? = 1, respectively. The derived limits for the ratio of the rest-frame 1.4 GHz luminosity density to the B-band optical luminosity density are R{sub 1.4}{sup ?}<0.53 and <4.30 for the above noted spectral indices, respectively. Given our upper limits on the radio continuum emission and the radio-to-optical luminosity ratio, we conclude that this quasar is radio-quiet and located at the low end of the radio-quiet distribution of high-redshift (z ? 6) quasars.

  7. CANDELS/GOODS-S, CDFS, and ECDFS: photometric redshifts for normal and X-ray-detected galaxies

    SciTech Connect (OSTI)

    Hsu, Li-Ting; Salvato, Mara; Nandra, Kirpal; Brusa, Marcella; Bender, Ralf; Buchner, Johannes; Brightman, Murray; Georgakakis, Antonis; Donley, Jennifer L.; Kocevski, Dale D.; Guo, Yicheng; Barro, Guillermo; Faber, Sandra M.; Rangel, Cyprian; Willner, S. P.; Ashby, Matthew L. N.; Budavri, Tams; Szalay, Alexander S.; Dahlen, Tomas; and others

    2014-11-20

    We present photometric redshifts and associated probability distributions for all detected sources in the Extended Chandra Deep Field South (ECDFS). This work makes use of the most up-to-date data from the Cosmic Assembly Near-IR Deep Legacy Survey (CANDELS) and the Taiwan ECDFS Near-Infrared Survey (TENIS) in addition to other data. We also revisit multi-wavelength counterparts for published X-ray sources from the 4 Ms CDFS and 250 ks ECDFS surveys, finding reliable counterparts for 1207 out of 1259 sources (?96%). Data used for photometric redshifts include intermediate-band photometry deblended using the TFIT method, which is used for the first time in this work. Photometric redshifts for X-ray source counterparts are based on a new library of active galactic nuclei/galaxy hybrid templates appropriate for the faint X-ray population in the CDFS. Photometric redshift accuracy for normal galaxies is 0.010 and for X-ray sources is 0.014 and outlier fractions are 4% and 5.2%, respectively. The results within the CANDELS coverage area are even better, as demonstrated both by spectroscopic comparison and by galaxy-pair statistics. Intermediate-band photometry, even if shallow, is valuable when combined with deep broadband photometry. For best accuracy, templates must include emission lines.

  8. ESTIMATING PHOTOMETRIC REDSHIFTS OF QUASARS VIA THE k-NEAREST NEIGHBOR APPROACH BASED ON LARGE SURVEY DATABASES

    SciTech Connect (OSTI)

    Zhang Yanxia; Ma He; Peng Nanbo; Zhao Yongheng; Wu Xuebing

    2013-08-01

    We apply one of the lazy learning methods, the k-nearest neighbor (kNN) algorithm, to estimate the photometric redshifts of quasars based on various data sets from the Sloan Digital Sky Survey (SDSS), the UKIRT Infrared Deep Sky Survey (UKIDSS), and the Wide-field Infrared Survey Explorer (WISE; the SDSS sample, the SDSS-UKIDSS sample, the SDSS-WISE sample, and the SDSS-UKIDSS-WISE sample). The influence of the k value and different input patterns on the performance of kNN is discussed. kNN performs best when k is different with a special input pattern for a special data set. The best result belongs to the SDSS-UKIDSS-WISE sample. The experimental results generally show that the more information from more bands, the better performance of photometric redshift estimation with kNN. The results also demonstrate that kNN using multiband data can effectively solve the catastrophic failure of photometric redshift estimation, which is met by many machine learning methods. Compared with the performance of various other methods of estimating the photometric redshifts of quasars, kNN based on KD-Tree shows superiority, exhibiting the best accuracy.

  9. RAPID, MACHINE-LEARNED RESOURCE ALLOCATION: APPLICATION TO HIGH-REDSHIFT GAMMA-RAY BURST FOLLOW-UP

    SciTech Connect (OSTI)

    Morgan, A. N.; Richards, Joseph W.; Butler, Nathaniel R.; Bloom, Joshua S. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Long, James; Broderick, Tamara, E-mail: amorgan@astro.berkeley.edu [Department of Statistics, University of California, Berkeley, CA 94720-3860 (United States)

    2012-02-20

    As the number of observed gamma-ray bursts (GRBs) continues to grow, follow-up resources need to be used more efficiently in order to maximize science output from limited telescope time. As such, it is becoming increasingly important to rapidly identify bursts of interest as soon as possible after the event, before the afterglows fade beyond detectability. Studying the most distant (highest redshift) events, for instance, remains a primary goal for many in the field. Here, we present our Random Forest Automated Triage Estimator for GRB redshifts (RATE GRB-z ) for rapid identification of high-redshift candidates using early-time metrics from the three telescopes onboard Swift. While the basic RATE methodology is generalizable to a number of resource allocation problems, here we demonstrate its utility for telescope-constrained follow-up efforts with the primary goal to identify and study high-z GRBs. For each new GRB, RATE GRB-z provides a recommendation-based on the available telescope time-of whether the event warrants additional follow-up resources. We train RATE GRB-z using a set consisting of 135 Swift bursts with known redshifts, only 18 of which are z > 4. Cross-validated performance metrics on these training data suggest that {approx}56% of high-z bursts can be captured from following up the top 20% of the ranked candidates, and {approx}84% of high-z bursts are identified after following up the top {approx}40% of candidates. We further use the method to rank 200 + Swift bursts with unknown redshifts according to their likelihood of being high-z.

  10. Giant magnetoelastic distortions of the crystal structure of the weakly anisotropic compound UFe/sub 2/

    SciTech Connect (OSTI)

    Popov, Y.F.; Levitin, R.Z.; Zeleny, M.; Deryagin, A.V.; Andreev, A.V.

    1980-06-01

    We investigate the temperature dependences of the crystal-lattice parameters, of the anisotropy, and of the Young's modulus of the intermetallide compound UFe/sub 2/. The contribution of the uranium ions to the magnetic moment of this compound is negligible (..mu../sub U/=0.06..mu../sub B/), owing to the almoft complete delocalization of the uranium 5f electrons. The measured magnetic anisotropy is relatively small (K/sub 1/approx. =-10/sup 6/ erg/cm/sup 3/ at 0 K). However, the transition to the magnetically ordered state (T/sub c/=170 K) is accompanied by large rhombohedral distortions of the UFe/sub 2/ crystal structure and by a considerable anomaly of the Young's modulus, thus attesting to a large value of the magnetoelastic interaction in this compound (..delta..K/sub 1/ /sup m/eapprox. =-8 x 10/sup 6/ erg/cm/sup 3/).

  11. Experimental and Numerical Analysis on the Distortion of Parts Made of 20MnCr5 by Hot Metal Forming

    SciTech Connect (OSTI)

    Rentsch, Ruediger; Brinksmeier, Ekkard [Stiftung Institut fuer Werkstofftechnik, Badgasteiner Strasse 3, 28359 Bremen (Germany)

    2011-05-04

    For high performance applications, shafts and gears made of 20MnCr5 (AISI 5120) are manufactured in large numbers every year. Inhomogeneities in the material properties, process perturbations and asymmetries in shape and operation setups provide a potential for the distortion of parts, often released by heat treatment. In this contribution experimental results on the distortion of shafts and the dishing of disk-like gear wheel blanks are presented. The numerical analysis of the hot-rolling process allowed to trace a peculiar segregation distribution at the cross-section of the bars back to the casting process, and to identify an asymmetric strain distribution which may be the main cause for shaft distortion. For the dishing of the disks a correlation to the resulting distribution of the material flow was found and, a process perturbation parameter identified which is assumed to be responsible for the observed material flow variation.

  12. HST/COS OBSERVATIONS OF THE QUASAR HE 2347-4342: PROBING THE EPOCH OF He II PATCHY REIONIZATION AT REDSHIFTS z = 2.4-2.9

    SciTech Connect (OSTI)

    Shull, J. Michael; France, Kevin; Danforth, Charles W.; Smith, Britton [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Tumlinson, Jason, E-mail: michael.shull@colorado.ed, E-mail: danforth@casa.colorado.ed, E-mail: kevin.france@colorado.ed, E-mail: britton.smith@colorado.ed, E-mail: tumlinson@stsci.ed [Space Telescope Science Institute, Baltimore, MD 21218 (United States)

    2010-10-20

    We report ultraviolet spectra of the high-redshift (z{sub em} {approx} 2.9) quasar, HE 2347 - 4342, taken by the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope. Spectra in the G130M (medium resolution, 1135-1440 A) and G140L (low resolution, 1030-2000 A) gratings exhibit patchy Gunn-Peterson absorption in the 303.78 A Ly{alpha} line of He II between z = 2.39-2.87 (G140L) and z = 2.74-2.90 (G130M). With COS, we obtain better spectral resolution, higher signal-to-noise ratio (S/N), and better determined backgrounds than previous studies, with sensitivity to abundance fractions x{sub He{sub II}} {approx} 0.01 in filaments of the cosmic web. The He II optical depths from COS are higher than those with the Far Ultraviolet Spectroscopic Explorer and range from {tau}{sub He{sub II}} {<=} 0.02 to {tau}{sub He{sub II}} {>=} 5, with a slow recovery in mean optical depth to ({tau}{sub He{sub II}}) {<=} 2 at z < 2.7. The He II/H I optical-depth ratio varies ({eta}{approx} 10-100 for 2.4 < z < 2.73 and {eta} = 5-500 for 2.75 < z < 2.89) on scales {Delta}z {approx}< 0.01 (10.8 Mpc in comoving radial distance at z = 2.8), with numerous flux-transmission windows between 1135 and 1186 A. The He II absorption extends to 1186.26 A (z = 2.905), including associated absorbers with z{sub abs} {approx} z{sub QSO} and minimal 'proximity effect' of flux transmission at the He II edge. We propose a QSO systemic redshift z{sub QSO} = 2.904 {+-} 0.002, some {Delta}z = 0.019 higher than that derived from O I {lambda}1302 emission. Three long troughs (4-10 A or 25-60 Mpc comoving distance) of strong He II absorption between z = 2.75and2.90 are uncharacteristic of the intergalactic medium if He II reionized at z{sub r} {approx} 3. Contrary to recent indirect estimates (z{sub r} = 3.2 {+-} 0.2) from H I optical depths, the epoch of He II reionization may extend to z {approx}< 2.7.

  13. PHOTOMETRIC REDSHIFTS IN THE HAWAII-HUBBLE DEEP FIELD-NORTH (H-HDF-N)

    SciTech Connect (OSTI)

    Yang, G.; Xue, Y. Q.; Kong, X.; Wang, J.-X.; Yuan, Y.-F.; Zhou, H. Y.; Luo, B.; Brandt, W. N.; Alexander, D. M.; Bauer, F. E.; Cui, W.; Lehmer, B. D.; Wu, X.-B.; Yuan, F. E-mail: xuey@ustc.edu.cn

    2015-01-01

    We derive photometric redshifts (z {sub phot}) for sources in the entire (?0.4deg{sup 2}) Hawaii-Hubble Deep Field-North (H-HDF-N) field with the EAzY code, based on point-spread-function-matched photometry of 15 broad bands from the ultraviolet (U band) to mid-infrared (IRAC 4.5 ?m). Our catalog consists of a total of 131,678sources. We evaluate the z {sub phot} quality by comparing z {sub phot} with spectroscopic redshifts (z {sub spec}) when available, and find a value of normalized median absolute deviation ?{sub NMAD} = 0.029 and an outlier fraction of 5.5% (outliers are defined as sources having |z{sub phot} z{sub spec} |/(1 + z{sub spec} ) > 0.15) for non-X-ray sources. More specifically, we obtain ?{sub NMAD}= 0.024 with 2.7% outliers for sources brighter than R = 23mag, ?{sub NMAD}= 0.035 with 7.4% outliers for sources fainter than R = 23mag, ?{sub NMAD}= 0.026 with 3.9% outliers for sources having z < 1, and ?{sub NMAD} = 0.034 with 9.0% outliers for sources having z > 1. Our z {sub phot} quality shows an overall improvement over an earlier z {sub phot} work that focused only on the central H-HDF-N area. We also classify each object as a star or galaxy through template spectral energy distribution fitting and complementary morphological parameterization, resulting in 4959 stars and 126,719 galaxies. Furthermore, we match our catalog with the 2Ms Chandra Deep Field-North main X-ray catalog. For the 462 matched non-stellar X-ray sources (281 having z {sub spec}), we improve their z {sub phot} quality by adding three additional active galactic nucleus templates, achieving ?{sub NMAD}= 0.035 and an outlier fraction of 12.5%. We make our catalog publicly available presenting both photometry and z {sub phot}, and provide guidance on how to make use of our catalog.

  14. Star formation relations and CO spectral line energy distributions across the J-ladder and redshift

    SciTech Connect (OSTI)

    Greve, T. R.; Leonidaki, I.; Xilouris, E. M.; Wei, A.; Henkel, C.; Zhang, Z.-Y.; Van der Werf, P.; Meijerink, R.; Aalto, S.; Armus, L.; Daz-Santos, T.; Evans, A. S.; Fischer, J.; Gao, Y.; Gonzlez-Alfonso, E.; Harris, A.; Naylor, D. A.; Smith, H. A.; Spaans, M.; and others

    2014-10-20

    We present FIR [50-300 ?m]CO luminosity relations (i.e., log L{sub FIR}=?log L{sub CO}{sup ?}+?) for the full CO rotational ladder from J = 1-0 up to J = 13-12 for a sample of 62 local (z ? 0.1) (Ultra) Luminous Infrared Galaxies (LIRGs; L {sub IR[8-1000} {sub ?m]} > 10{sup 11} L {sub ?}) using data from Herschel SPIRE-FTS and ground-based telescopes. We extend our sample to high redshifts (z > 1) by including 35 submillimeter selected dusty star forming galaxies from the literature with robust CO observations, and sufficiently well-sampled FIR/submillimeter spectral energy distributions (SEDs), so that accurate FIR luminosities can be determined. The addition of luminous starbursts at high redshifts enlarge the range of the FIRCO luminosity relations toward the high-IR-luminosity end, while also significantly increasing the small amount of mid-J/high-J CO line data (J = 5-4 and higher) that was available prior to Herschel. This new data set (both in terms of IR luminosity and J-ladder) reveals linear FIRCO luminosity relations (i.e., ? ? 1) for J = 1-0 up to J = 5-4, with a nearly constant normalization (? ? 2). In the simplest physical scenario, this is expected from the (also) linear FIR(molecular line) relations recently found for the dense gas tracer lines (HCN and CS), as long as the dense gas mass fraction does not vary strongly within our (merger/starburst)-dominated sample. However, from J = 6-5 and up to the J = 13-12 transition, we find an increasingly sublinear slope and higher normalization constant with increasing J. We argue that these are caused by a warm (?100 K) and dense (>10{sup 4} cm{sup 3}) gas component whose thermal state is unlikely to be maintained by star-formation-powered far-UV radiation fields (and thus is no longer directly tied to the star formation rate). We suggest that mechanical heating (e.g., supernova-driven turbulence and shocks), and not cosmic rays, is the more likely source of energy for this component. The global CO spectral line energy distributions, which remain highly excited from J = 6-5 up to J = 13-12, are found to be a generic feature of the (U)LIRGs in our sample, and further support the presence of this gas component.

  15. DUST EXTINCTION BIAS IN THE COLUMN DENSITY DISTRIBUTION OF GAMMA-RAY BURSTS: HIGH COLUMN DENSITY, LOW-REDSHIFT GRBs ARE MORE HEAVILY OBSCURED

    SciTech Connect (OSTI)

    Watson, Darach [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark); Jakobsson, Pall, E-mail: darach@dark-cosmology.dk, E-mail: pja@raunvis.hi.is [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhaga 5, IS-107 Reykjavik (Iceland)

    2012-08-01

    The afterglows of gamma-ray bursts (GRBs) have more soft-X-ray absorption than expected from the foreground gas column in the Galaxy. While the redshift of the absorption can in general not be constrained from current X-ray observations, it has been assumed that the absorption is due to metals in the host galaxy of the GRB. The large sample of X-ray afterglows and redshifts now available allows the construction of statistically meaningful distributions of the metal column densities. We construct such a sample and show, as found in previous studies, that the typical absorbing column density (N{sub H{sub X}}) increases substantially with redshift, with few high column density objects found at low-to-moderate redshifts. We show, however, that when highly extinguished bursts are included in the sample, using redshifts from their host galaxies, high column density sources are also found at low-to-moderate redshift. We infer from individual objects in the sample and from observations of blazars that the increase in column density with redshift is unlikely to be related to metals in the intergalactic medium or intervening absorbers. Instead we show that the origin of the apparent increase with redshift is primarily due to dust extinction bias: GRBs with high X-ray absorption column densities found at z {approx}< 4 typically have very high dust extinction column densities, while those found at the highest redshifts do not. It is unclear how such a strongly evolving N{sub H{sub X}}/A{sub V} ratio would arise, and based on current data, remains a puzzle.

  16. Synchrotron Radiation Wake in Free Space

    SciTech Connect (OSTI)

    Stupakov, G.V.; /SLAC

    2011-08-31

    In this paper, we derive the transverse radiation force of a bunch of ultrarelativistic charged particles coherently radiating in free space assuming that the bending radius is much larger than the beam dimensions. In contrast to a similar recent study, where the authors decompose the total transverse force and find only a part that is responsible for the distortion of the beam orbit, we derive a full expression for the force and leave the issues of the beam dynamics for a separate consideration. Another approach to the calculation of the transverse force has been previously developed. In many cases considered in this paper, the calculations are extremely cumbersome; they were systematically performed with the use of symbolic engine of the computer program MATHEMATICA.

  17. Study of redshifted H I from the epoch of reionization with drift scan

    SciTech Connect (OSTI)

    Paul, Sourabh; Sethi, Shiv K.; Subrahmanyan, Ravi; Shankar, N. Udaya; Dwarakanath, K. S.; Deshpande, Avinash A.; Bernardi, Gianni; Bowman, Judd D.; Briggs, Frank; Gaensler, Bryan M.; Cappallo, Roger J.; Corey, Brian E.; Goeke, Robert F.; Emrich, David; Greenhill, Lincoln J.; Kasper, Justin C.; Hazelton, Bryna J.; Hewitt, Jacqueline N.; Johnston-Hollitt, Melanie; Kaplan, David L. E-mail: sethi@rri.res.in; and others

    2014-09-20

    Detection of the epoch of reionization (EoR) in the redshifted 21 cm line is a challenging task. Here, we formulate the detection of the EoR signal using the drift scan strategy. This method potentially has better instrumental stability compared to the case where a single patch of sky is tracked. We demonstrate that the correlation time between measured visibilities could extend up to 1-2 hr for an interferometer array such as the Murchison Widefield Array, which has a wide primary beam. We estimate the EoR power based on a cross-correlation of visibilities over time and show that the drift scan strategy is capable of detecting the EoR signal with a signal to noise that is comparable/better compared to the tracking case. We also estimate the visibility correlation for a set of bright point sources and argue that the statistical inhomogeneity of bright point sources might allow their separation from the EoR signal.

  18. Spatial and kinematic distributions of transition populations in intermediate redshift galaxy clusters

    SciTech Connect (OSTI)

    Crawford, Steven M.; Wirth, Gregory D.; Bershady, Matthew A. E-mail: wirth@keck.hawaii.edu

    2014-05-01

    We analyze the spatial and velocity distributions of confirmed members in five massive clusters of galaxies at intermediate redshift (0.5 < z < 0.9) to investigate the physical processes driving galaxy evolution. Based on spectral classifications derived from broad- and narrow-band photometry, we define four distinct galaxy populations representing different evolutionary stages: red sequence (RS) galaxies, blue cloud (BC) galaxies, green valley (GV) galaxies, and luminous compact blue galaxies (LCBGs). For each galaxy class, we derive the projected spatial and velocity distribution and characterize the degree of subclustering. We find that RS, BC, and GV galaxies in these clusters have similar velocity distributions, but that BC and GV galaxies tend to avoid the core of the two z ? 0.55 clusters. GV galaxies exhibit subclustering properties similar to RS galaxies, but their radial velocity distribution is significantly platykurtic compared to the RS galaxies. The absence of GV galaxies in the cluster cores may explain their somewhat prolonged star-formation history. The LCBGs appear to have recently fallen into the cluster based on their larger velocity dispersion, absence from the cores of the clusters, and different radial velocity distribution than the RS galaxies. Both LCBG and BC galaxies show a high degree of subclustering on the smallest scales, leading us to conclude that star formation is likely triggered by galaxy-galaxy interactions during infall into the cluster.

  19. A redshift survey of the strong-lensing cluster ABELL 383

    SciTech Connect (OSTI)

    Geller, Margaret J.; Hwang, Ho Seong; Kurtz, Michael J.; Diaferio, Antonaldo; Coe, Dan; Rines, Kenneth J. E-mail: hhwang@cfa.harvard.edu E-mail: diaferio@ph.unito.it E-mail: kenneth.rines@wwu.edu

    2014-03-01

    Abell 383 is a famous rich cluster (z = 0.1887) imaged extensively as a basis for intensive strong- and weak-lensing studies. Nonetheless, there are few spectroscopic observations. We enable dynamical analyses by measuring 2360 new redshifts for galaxies with r {sub Petro} ≤ 20.5 and within 50' of the Brightest Cluster Galaxy (BCG; R.A.{sub 2000} = 42.°014125, decl.{sub 2000} = –03.°529228). We apply the caustic technique to identify 275 cluster members within 7 h {sup –1} Mpc of the hierarchical cluster center. The BCG lies within –11 ± 110 km s{sup –1} and 21 ± 56 h {sup –1} kpc of the hierarchical cluster center; the velocity dispersion profile of the BCG appears to be an extension of the velocity dispersion profile based on cluster members. The distribution of cluster members on the sky corresponds impressively with the weak-lensing contours of Okabe et al. especially when the impact of foreground and background structure is included. The values of R {sub 200} = 1.22 ± 0.01 h {sup –1} Mpc and M {sub 200} = (5.07 ± 0.09) × 10{sup 14} h {sup –1} M {sub ☉} obtained by application of the caustic technique agree well with recent completely independent lensing measures. The caustic estimate extends direct measurement of the cluster mass profile to a radius of ∼5 h {sup –1} Mpc.

  20. ON THE CORRELATION OF LOW-ENERGY SPECTRAL INDICES AND REDSHIFTS OF GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Geng, J. J.; Huang, Y. F., E-mail: hyf@nju.edu.cn [Department of Astronomy, Nanjing University, Nanjing 210093 (China)

    2013-02-10

    It was found by Amati et al. in 2002 that for a small sample of nine gamma-ray bursts (GRBs), more distant events appear to be systematically harder in the soft gamma-ray band. Here, we have collected a larger sample of 65 GRBs, whose time-integrated spectra are well established and can be well fitted with the so-called Band function. It is confirmed that a correlation between the redshifts (z) and the low-energy indices ({alpha}) of the Band function does exist, though it is a bit more scattered than the result of Amati et al. This correlation cannot be simply attributed to the effect of photon reddening. Furthermore, correlations between {alpha} and E {sub peak} (the peak energy in the {nu}F {sub {nu}} spectrum in the rest frame), {alpha} and E {sub iso} (the isotropic energy release), and {alpha} and L {sub iso} (the isotropic luminosity) are also found, which indicate that these parameters are somehow connected. The results may provide useful constraints on the physics of GRBs.

  1. The high-redshift gamma-ray burst GRB 140515A

    SciTech Connect (OSTI)

    Melandri, A.; Bernardini, M. G.; D'Avanzo, P. D.; Sanchez-Ramirez, R.; Nappo, F.; Nava, L.; Japelj, J.; de Ugarte Postigo, A.; Oates, S.; Campana, S.; Covino, S.; D'Elia, V.; Ghirlanda, G.; Gafton, E.; Ghisellini, G.; Gnedin, N.; Goldoni, P.; Gorosabel, J.; Libbrecht, T.; Malesani, D.; Salvaterra, R.; Thone, C. C.; Vergani, S. D.; Xu, D.; Tagliaferri, G.

    2015-09-09

    High-redshift gamma-ray bursts (GRBs) offer several advantages when studying the distant Universe, providing unique information about the structure and properties of the galaxies in which they exploded. Spectroscopic identification with large ground-based telescopes has improved our knowledge of this kind of distant events. We present the multi-wavelength analysis of the high-zSwift GRB GRB 140515A (z = 6.327). The best estimate of the neutral hydrogen fraction of the intergalactic medium towards the burst is xHI ? 0.002. The spectral absorption lines detected for this event are the weakest lines ever observed in GRB afterglows, suggesting that GRB 140515A exploded in a very low-density environment. Its circum-burst medium is characterised by an average extinction (AV ~ 0.1) that seems to be typical of z ? 6 events. The observed multi-band light curves are explained either with a very hard injected spectrum (p = 1.7) or with a multi-component emission (p = 2.1). In the second case a long-lasting central engine activity is needed in order to explain the late time X-ray emission. Furthermore, the possible origin of GRB 140515A in a Pop III (or in a Pop II star with a local environment enriched by Pop III) massive star is unlikely.

  2. ON MEASURING THE COSMIC MICROWAVE BACKGROUND TEMPERATURE AT REDSHIFT 0.89

    SciTech Connect (OSTI)

    Sato, M.; Menten, K. M.; Reid, M. J.; Carilli, C. L.

    2013-02-20

    We report on a measurement of the temperature of the cosmic microwave background radiation field, T {sub CMB}, at z = 0.88582 by imaging HC{sub 3}N(3 <- 2) and (5 <- 4) absorption in the foreground galaxy of the gravitationally lens magnified radio source PKS 1830-211 using the Very Long Baseline Array and the phased Very Large Array. Low-resolution imaging of the data yields a value of T {sub rot} = 5.6{sup +2.5} {sub -0.9} K for the rotational temperature, T {sub rot}, which is consistent with the temperature of the cosmic microwave background at the absorber's redshift of 2.73(1 + z) K. However, our high-resolution imaging reveals that the absorption peak position of the foreground gas is offset from the continuum peak position of the synchrotron radiation from PKS 1830-211SW, which indicates that the absorbing cloud is covering only part of the emission from PKS 1830-211, rather than the entire core-jet region. This changes the line-to-continuum ratios, and we find T {sub rot} between 1.1 and 2.5 K, which is lower than the expected value. This shows that previous T {sub rot} measurements could be biased due to unresolved structure.

  3. The high-redshift gamma-ray burst GRB 140515A

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

    Melandri, A.; Bernardini, M. G.; D'Avanzo, P. D.; Sanchez-Ramirez, R.; Nappo, F.; Nava, L.; Japelj, J.; de Ugarte Postigo, A.; Oates, S.; Campana, S.; et al

    2015-09-09

    High-redshift gamma-ray bursts (GRBs) offer several advantages when studying the distant Universe, providing unique information about the structure and properties of the galaxies in which they exploded. Spectroscopic identification with large ground-based telescopes has improved our knowledge of this kind of distant events. We present the multi-wavelength analysis of the high-zSwift GRB GRB 140515A (z = 6.327). The best estimate of the neutral hydrogen fraction of the intergalactic medium towards the burst is xHI ≤ 0.002. The spectral absorption lines detected for this event are the weakest lines ever observed in GRB afterglows, suggesting that GRB 140515A exploded in amore » very low-density environment. Its circum-burst medium is characterised by an average extinction (AV ~ 0.1) that seems to be typical of z ≥ 6 events. The observed multi-band light curves are explained either with a very hard injected spectrum (p = 1.7) or with a multi-component emission (p = 2.1). In the second case a long-lasting central engine activity is needed in order to explain the late time X-ray emission. Furthermore, the possible origin of GRB 140515A in a Pop III (or in a Pop II star with a local environment enriched by Pop III) massive star is unlikely.« less

  4. Space Solar Power Program

    SciTech Connect (OSTI)

    Arif, H.; Barbosa, H.; Bardet, C.; Baroud, M.; Behar, A.; Berrier, K.; Berthe, P.; Bertrand, R.; Bibyk, I.; Bisson, J.; Bloch, L.; Bobadilla, G.; Bourque, D.; Bush, L.; Carandang, R.; Chiku, T.; Crosby, N.; De Seixas, M.; De Vries, J.; Doll, S.; Dufour, F.; Eckart, P.; Fahey, M.; Fenot, F.; Foeckersperger, S.; Fontaine, J.E.; Fowler, R.; Frey, H.; Fujio, H.; Gasa, J.M.; Gleave, J.; Godoe, J.; Green, I.; Haeberli, R.; Hanada, T.; Ha

    1992-08-01

    Information pertaining to the Space Solar Power Program is presented on energy analysis; markets; overall development plan; organizational plan; environmental and safety issues; power systems; space transportation; space manufacturing, construction, operations; design examples; and finance.

  5. MEASUREMENTS OF CO REDSHIFTS WITH Z-SPEC FOR LENSED SUBMILLIMETER GALAXIES DISCOVERED IN THE H-ATLAS SURVEY

    SciTech Connect (OSTI)

    Lupu, R. E.; Scott, K. S.; Aguirre, J. E.; Aretxaga, I.; Auld, R.; Dariush, A.; Barton, E.; Cooke, J.; Cooray, A.; Beelen, A.; Bertoldi, F.; Bock, J. J.; Bradford, C. M.; Bonfield, D.; Buttiglione, S.; De Zotti, G.; Cava, A.; Dannerbauer, H.; and others

    2012-10-01

    We present new observations from Z-Spec, a broadband 185-305 GHz spectrometer, of five submillimeter bright lensed sources selected from the Herschel-Astrophysical Terahertz Large Area Survey science demonstration phase catalog. We construct a redshift-finding algorithm using combinations of the signal to noise of all the lines falling in the Z-Spec bandpass to determine redshifts with high confidence, even in cases where the signal to noise in individual lines is low. We measure the dust continuum in all sources and secure CO redshifts for four out of five (z {approx} 1.5-3). In one source, SDP.17, we tentatively identify two independent redshifts and a water line, confirmed at z = 2.308. Our sources have properties characteristic of dusty starburst galaxies, with magnification-corrected star formation rates of 10{sup 2-3} M{sub Sun} yr{sup -1}. Lower limits for the dust masses ({approx} a few 10{sup 8} M{sub Sun }) and spatial extents ({approx}1 kpc equivalent radius) are derived from the continuum spectral energy distributions, corresponding to dust temperatures between 54 and 69 K. In the local thermodynamic equilibrium (LTE) approximation, we derive relatively low CO excitation temperatures ({approx}< 100 K) and optical depths ({tau} {approx}< 1). Performing a non-LTE excitation analysis using RADEX, we find that the CO lines measured by Z-Spec (from J = 4 {yields} 3 to 10 {yields} 9, depending on the galaxy) localize the best solutions to either a high-temperature/low-density region or a low/temperature/high-density region near the LTE solution, with the optical depth varying accordingly. Observations of additional CO lines, CO(1-0) in particular, are needed to constrain the non-LTE models.

  6. Discovery of Very High Energy Gamma Rays from PKS 1424+240 and Multiwavelength Constraints on its Redshift

    SciTech Connect (OSTI)

    Acciari, V.A.; Aliu, E.; Arlen, T.; Aune, T.; Bautista, M.; Beilicke, M. Benbow, W.; Bottcher, M.; Boltuch, D.; Bradbury, S.M.; Buckley, J.H.; Bugaev, V.; Byrum, K.; Cannon, A.; Cesarini, A.; Chow, Y.C.; Ciupik, L.; Cogan, P.; Cui, W.; Duke, C.; Falcone, A.; /more authors..

    2012-04-05

    We report the first detection of very-high-energy (VHE) gamma-ray emission above 140GeV from PKS 1424+240, a BL Lac object with an unknown redshift. The photon spectrum above 140GeV measured by VERITAS is well described by a power law with a photon index of 3.8 {+-}0.5{sub stat} {+-} 0.3{sub syst} and a flux normalization at 200 GeV of (5.1 {+-} 0.9{sub stat} {+-} 0.5{sub syst}) x 10{sup -11} TeV{sup -1} cm{sup -2} s{sup -1}, where stat and syst denote the statistical and systematical uncertainty, respectively. The VHE flux is steady over the observation period between MJD 54881 and 55003 (2009 February 19 to June 21). Flux variability is also not observed in contemporaneous high energy observations with the Fermi Large Area Telescope (LAT). Contemporaneous X-ray and optical data were also obtained from the Swift XRT and MDM observatory, respectively. The broadband spectral energy distribution (SED) is well described by a one-zone synchrotron self-Compton (SSC) model favoring a redshift of less than 0.1. Using the photon index measured with Fermi in combination with recent extragalactic background light (EBL) absorption models it can be concluded from the VERITAS data that the redshift of PKS 1424+240 is less than 0.66.

  7. THE LOW-REDSHIFT INTERGALACTIC MEDIUM AS SEEN IN ARCHIVAL LEGACY HST/STIS AND FUSE DATA

    SciTech Connect (OSTI)

    Tilton, Evan M.; Danforth, Charles W.; Michael Shull, J. [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Ross, Teresa L., E-mail: evan.tilton@colorado.edu, E-mail: charles.danforth@colorado.edu, E-mail: michael.shull@colorado.edu, E-mail: rosst@nmsu.edu [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States)

    2012-11-10

    We present a comprehensive catalog of ultraviolet (HST/STIS and FUSE) absorbers in the low-redshift intergalactic medium (IGM) at z < 0.4. The catalog draws from much of the extensive literature on IGM absorption and reconciles discrepancies among several previous catalogs through a critical evaluation of all reported absorption features in light of new HST/COS data. We report on 746 H I absorbers down to a rest-frame equivalent width of 12 mA over a maximum redshift path length {Delta}z = 5.38. We also confirm 111 O VI absorbers, 29 C IV absorbers, and numerous absorption lines due to other metal ions. We characterize the bivariate distribution of absorbers in redshift and column density as a power law, {partial_derivative}{sup 2}N/{partial_derivative}z{partial_derivative}N) {proportional_to} N{sup -{beta}}, where {beta} = 2.08 {+-} 0.12 for O VI and {beta} = 1.68 {+-} 0.03 for H I. Utilizing a more sophisticated accounting technique than past work, our catalog accounts for {approx}43% of the baryons: 24% {+-} 2% in the photoionized Ly{alpha} forest and 19% {+-} 2% in the warm-hot IGM as traced by O VI. We discuss the large systematic effects of various assumed metallicities and ionization states on these calculations, and we implement recent simulation results in our estimates.

  8. An Insertion Mutation That Distorts Antibody Binding Site Architecture Enhances Function of a Human Antibody

    SciTech Connect (OSTI)

    Krause, Jens C.; Ekiert, Damian C.; Tumpey, Terrence M.; Smith, Patricia B.; Wilson, Ian A.; Crowe, Jr., James E.

    2011-09-02

    The structural and functional significance of somatic insertions and deletions in antibody chains is unclear. Here, we demonstrate that a naturally occurring three-amino-acid insertion within the influenza virus-specific human monoclonal antibody 2D1 heavy-chain variable region reconfigures the antibody-combining site and contributes to its high potency against the 1918 and 2009 pandemic H1N1 influenza viruses. The insertion arose through a series of events, including a somatic point mutation in a predicted hot-spot motif, introduction of a new hot-spot motif, a molecular duplication due to polymerase slippage, a deletion due to misalignment, and additional somatic point mutations. Atomic resolution structures of the wild-type antibody and a variant in which the insertion was removed revealed that the three-amino-acid insertion near the base of heavy-chain complementarity-determining region (CDR) H2 resulted in a bulge in that loop. This enlarged CDR H2 loop impinges on adjacent regions, causing distortion of the CDR H1 architecture and its displacement away from the antigen-combining site. Removal of the insertion restores the canonical structure of CDR H1 and CDR H2, but binding, neutralization activity, and in vivo activity were reduced markedly because of steric conflict of CDR H1 with the hemagglutinin antigen.

  9. Analysis of the orbit distortion by the use of the wavelet transform

    SciTech Connect (OSTI)

    Matsushita, T.; Takao, M.; Aoyagi, H.; Takeuchi, M.; Tanaka, H.; Agui, A.; Yoshigoe, A.; Nakatani, T.

    2004-05-12

    We have adopted matching pursuit algorithm of discrete wavelet transform (DWT) for the analysis of the beam position shift correlated with the motion of insertion device (ID). The beam position data measured by the rf beam position monitors have included high-frequency 'noises' and fluctuation of background level. Precise evaluation of the electron beam position shift correlated with the motion of the ID is required for estimation of the steering magnet currents in order to suppress the closed orbit distortion (COD). The DWT is a powerful tool for frequency analysis and data processing. The analysis of DWT was applied to the beam position shift correlated with the phase motion of APPLE-2 type undulator (ID23) in SPring-8. The result of the analysis indicated that 'noises' are mainly composed of the components of 50 {approx} 6.25Hz and < 0.1Hz. We carried out the data processing to remove the 'noises' by the matching pursuit algorithm. Then we have succeeded in suppressing the COD within 2 {mu}m by the use of the steering magnet currents calculated from the processed data.

  10. Distorting general relativity: gravity's rainbow and f(R) theories at work

    SciTech Connect (OSTI)

    Garattini, Remo

    2013-06-01

    We compute the Zero Point Energy in a spherically symmetric background combining the high energy distortion of Gravity's Rainbow with the modification induced by a f(R) theory. Here f(R) is a generic analytic function of the Ricci curvature scalar R in 4D and in 3D. The explicit calculation is performed for a Schwarzschild metric. Due to the spherically symmetric property of the Schwarzschild metric we can compare the effects of the modification induced by a f(R) theory in 4D and in 3D. We find that the final effect of the combined theory is to have finite quantities that shift the Zero Point Energy. In this context we setup a Sturm-Liouville problem with the cosmological constant considered as the associated eigenvalue. The eigenvalue equation is a reformulation of the Wheeler-DeWitt equation which is analyzed by means of a variational approach based on gaussian trial functionals. With the help of a canonical decomposition, we find that the relevant contribution to one loop is given by the graviton quantum fluctuations around the given background. A final discussion on the connection of our result with the observed cosmological constant is also reported.

  11. HerMES: Candidate high-redshift galaxies discovered with Herschel/Spire

    SciTech Connect (OSTI)

    Dowell, C. Darren; Bock, J.; Bridge, C.; Cooray, A.; Conley, A.; Glenn, J.; Arumugam, V.; Asboth, V.; Aussel, H.; Bthermin, M.; Boselli, A.; Buat, V.; Burgarella, D.; Cabrera-Lavers, A.; Casey, C. M.; Chapman, S. C.; Clements, D. L.; Conversi, L.; Dannerbauer, H.; and others

    2014-01-01

    We present a method for selecting z > 4 dusty, star-forming galaxies (DSFGs) using Herschel/Spectral and Photometric Imaging Receiver 250/350/500 ?m flux densities to search for red sources. We apply this method to 21 deg{sup 2} of data from the HerMES survey to produce a catalog of 38 high-z candidates. Follow-up of the first five of these sources confirms that this method is efficient at selecting high-z DSFGs, with 4/5 at z = 4.3-6.3 (and the remaining source at z = 3.4), and that they are some of the most luminous dusty sources known. Comparison with previous DSFG samples, mostly selected at longer wavelengths (e.g., 850 ?m) and in single-band surveys, shows that our method is much more efficient at selecting high-z DSFGs, in the sense that a much larger fraction are at z > 3. Correcting for the selection completeness and purity, we find that the number of bright (S {sub 500} {sub ?m} ? 30 mJy), red Herschel sources is 3.3 0.8 deg{sup 2}. This is much higher than the number predicted by current models, suggesting that the DSFG population extends to higher redshifts than previously believed. If the shape of the luminosity function for high-z DSFGs is similar to that at z ? 2, rest-frame UV based studies may be missing a significant component of the star formation density at z = 4-6, even after correction for extinction.

  12. Self-calibration of photometric redshift scatter in weak-lensing surveys

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

    Zhang, Pengjie; Pen, Ue -Li; Bernstein, Gary

    2010-06-11

    Photo-z errors, especially catastrophic errors, are a major uncertainty for precision weak lensing cosmology. We find that the shear-(galaxy number) density and density-density cross correlation measurements between photo-z bins, available from the same lensing surveys, contain valuable information for self-calibration of the scattering probabilities between the true-z and photo-z bins. The self-calibration technique we propose does not rely on cosmological priors nor parameterization of the photo-z probability distribution function, and preserves all of the cosmological information available from shear-shear measurement. We estimate the calibration accuracy through the Fisher matrix formalism. We find that, for advanced lensing surveys such as themore » planned stage IV surveys, the rate of photo-z outliers can be determined with statistical uncertainties of 0.01-1% for z < 2 galaxies. Among the several sources of calibration error that we identify and investigate, the galaxy distribution bias is likely the most dominant systematic error, whereby photo-z outliers have different redshift distributions and/or bias than non-outliers from the same bin. This bias affects all photo-z calibration techniques based on correlation measurements. As a result, galaxy bias variations of O(0.1) produce biases in photo-z outlier rates similar to the statistical errors of our method, so this galaxy distribution bias may bias the reconstructed scatters at several-σ level, but is unlikely to completely invalidate the self-calibration technique.« less

  13. Self-calibration of photometric redshift scatter in weak-lensing surveys

    SciTech Connect (OSTI)

    Zhang, Pengjie; Pen, Ue -Li; Bernstein, Gary

    2010-06-11

    Photo-z errors, especially catastrophic errors, are a major uncertainty for precision weak lensing cosmology. We find that the shear-(galaxy number) density and density-density cross correlation measurements between photo-z bins, available from the same lensing surveys, contain valuable information for self-calibration of the scattering probabilities between the true-z and photo-z bins. The self-calibration technique we propose does not rely on cosmological priors nor parameterization of the photo-z probability distribution function, and preserves all of the cosmological information available from shear-shear measurement. We estimate the calibration accuracy through the Fisher matrix formalism. We find that, for advanced lensing surveys such as the planned stage IV surveys, the rate of photo-z outliers can be determined with statistical uncertainties of 0.01-1% for z < 2 galaxies. Among the several sources of calibration error that we identify and investigate, the galaxy distribution bias is likely the most dominant systematic error, whereby photo-z outliers have different redshift distributions and/or bias than non-outliers from the same bin. This bias affects all photo-z calibration techniques based on correlation measurements. As a result, galaxy bias variations of O(0.1) produce biases in photo-z outlier rates similar to the statistical errors of our method, so this galaxy distribution bias may bias the reconstructed scatters at several-? level, but is unlikely to completely invalidate the self-calibration technique.

  14. A CLOSE-PAIR ANALYSIS OF DAMP MERGERS AT INTERMEDIATE REDSHIFTS

    SciTech Connect (OSTI)

    Chou, Richard C. Y.; Abraham, Roberto G.; Bridge, Carrie R. E-mail: abraham@astro.utoronto.ca

    2012-12-01

    We have studied the kinematics of {approx}2800 candidate close-pair galaxies at 0.1 < z < 1.2 identified from the Canada-France-Hawaii Telescope Legacy Survey fields. Spectra of these systems were obtained using spectrometers on the 6.5 m Magellan and 5 m Hale telescopes. These data allow us to constrain the rate of dry mergers at intermediate redshifts and to test the 'hot halo' model for quenching of star formation. Using virial radii estimated from the correlation between dynamical and stellar masses published by Leauthaud et al., we find that around 1/5 of our candidate pairs are likely to share a common dark matter halo (our metric for close physical association). These pairs are divided into red-red, blue-red, and blue-blue systems using the rest-frame colors classification method introduced in Chou et al.. Galaxies classified as red in our sample have very low star formation rates, but they need not be totally quiescent, and hence we refer to them as 'damp', rather than 'dry', systems. After correcting for known selection effects, the fraction of blue-blue pairs is significantly greater than that of red-red and blue-red pairs. Red-red pairs are almost entirely absent from our sample, suggesting that damp mergers are rare at z {approx} 0.5. Our data support models with a short merging timescale (<0.5 Gyr) in which star formation is enhanced in the early phase of mergers, but quenched in the late phase. Hot halo models may explain this behavior, but only if virial shocks that heat gas are inefficient until major mergers are nearly complete.

  15. Space and Sensors

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

    Space and Sensors Space and Sensors Create, deliver, support, and exploit innovative sensing systems for space-based, airborne and ground-based applications to address critical national security and scientific challenges. Contact thumbnail of Business Development Executive Michael Erickson Business Development Executive Richard P. Feynman Center for Innovation (505) 667-8087 Email Space Create, deliver, support, and exploit innovative sensing systems for space-based, airborne and ground-based

  16. Local structure underlying anomalous tetragonal distortions in BiFeO{sub 3}-PbTiO{sub 3} ferroelectrics

    SciTech Connect (OSTI)

    Levin, I.; Krayzman, V.; Woicik, J. C.; Tucker, M. G.

    2014-06-16

    The local structure of tetragonal BiFeO{sub 3}-PbTiO{sub 3} solid solutions featuring anomalous lattice distortions has been determined using simultaneous fitting of neutron total scattering and extended X-ray absorption fine structure data. On the local scale, the large tetragonal distortion, promoted by the displacements of the A-cations (Bi and Pb), is accommodated primarily by the [FeO{sub 6}] octahedra, even though both Fe and Ti acquire (5+1)-fold coordination. Bi cations exhibit considerably larger displacements than Pb. The combination of the A-cation displacements and the ability of M-cations to adopt 5-fold coordination is suggested as key for stabilizing the large tetragonality in BiMO{sub 3}-PbTiO{sub 3} systems.

  17. Enhanced hydrogenation and reduced lattice distortion in size selected Pd-Ag and Pd-Cu alloy nanoparticles

    SciTech Connect (OSTI)

    Sengar, Saurabh K.; Mehta, B. R.; Kulriya, P. K.; Khan, S. A.

    2013-10-21

    Important correlation between valence band spectra and hydrogenation properties in Pd alloy nanoparticles is established by studying the properties of size selected and monocrystalline Pd, Ag, Cu, Pd-Ag, and Pd-Cu nanoparticles. The X-ray photoelectron spectroscopy and elastic recoil detection analysis show that size induced Pd4d centroid shift is related to enhanced hydrogenation with H/Pd ratio of 0.57 and 0.49 in Pd-Ag and Pd-Cu nanoparticles in comparison to reported bulk values of 0.2 and 0.1, respectively. Pd-alloy nanoparticles show lower hydrogen induced lattice distortion. The reduced distortion and higher hydrogen reactivity of Pd-alloy nanoparticles is important for numerous hydrogen related applications.

  18. The redshift evolution of the mean temperature, pressure, and entropy profiles in 80 SPT-selected galaxy clusters

    SciTech Connect (OSTI)

    McDonald, M.; Bautz, M.; Benson, B. A.; Vikhlinin, A.; Bayliss, M.; Forman, W. R.; Aird, K. A.; Allen, S. W.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Bocquet, S.; Brodwin, M.; Cho, H. M.; Clocchiatti, A.; De Haan, T.; Dobbs, M. A.; Foley, R. J.; and others

    2014-10-10

    We present the results of an X-ray analysis of 80 galaxy clusters selected in the 2500 deg{sup 2} South Pole Telescope survey and observed with the Chandra X-ray Observatory. We divide the full sample into subsamples of ?20 clusters based on redshift and central density, performing a joint X-ray spectral fit to all clusters in a subsample simultaneously, assuming self-similarity of the temperature profile. This approach allows us to constrain the shape of the temperature profile over 0 < r < 1.5R {sub 500}, which would be impossible on a per-cluster basis, since the observations of individual clusters have, on average, 2000 X-ray counts. The results presented here represent the first constraints on the evolution of the average temperature profile from z = 0 to z = 1.2. We find that high-z (0.6 < z < 1.2) clusters are slightly (?30%) cooler both in the inner (r < 0.1R {sub 500}) and outer (r > R {sub 500}) regions than their low-z (0.3 < z < 0.6) counterparts. Combining the average temperature profile with measured gas density profiles from our earlier work, we infer the average pressure and entropy profiles for each subsample. Confirming earlier results from this data set, we find an absence of strong cool cores at high z, manifested in this analysis as a significantly lower observed pressure in the central 0.1R {sub 500} of the high-z cool-core subset of clusters compared to the low-z cool-core subset. Overall, our observed pressure profiles agree well with earlier lower-redshift measurements, suggesting minimal redshift evolution in the pressure profile outside of the core. We find no measurable redshift evolution in the entropy profile at r ? 0.7R {sub 500}this may reflect a long-standing balance between cooling and feedback over long timescales and large physical scales. We observe a slight flattening of the entropy profile at r ? R {sub 500} in our high-z subsample. This flattening is consistent with a temperature bias due to the enhanced (?3) rate at which group-mass (?2 keV) halos, which would go undetected at our survey depth, are accreting onto the cluster at z ? 1. This work demonstrates a powerful method for inferring spatially resolved cluster properties in the case where individual cluster signal-to-noise is low, but the number of observed clusters is high.

  19. Space Science and Applications

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

    the first measurements of Earth's space radiation environment and the discovery of gamma-ray bursts. The majority of ISR-1 staff hold PhDs in Space Physics, Nuclear Physics, or...

  20. 50 Years of Space

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

    50 Years of Space /science-innovation/_assets/images/icon-science.jpg 50 Years of Space Since 1943, some of the world's smartest and most dedicated technical people have accomplished the difficult, the unexpected, and what sometimes seems impossible at Los Alamos. LANL Top Science 2014 Faces of Science Radical Supercomputing Science Digests 70 Years of Innovations Top Ten Innovations of 2013 Energy Sustainability 50 Years of Space 50 YEARS OF SPACE Creating a safer, more secure tomorrow x x 1955

  1. TANK SPACE OPTIONS REPORT

    SciTech Connect (OSTI)

    WILLIS WL; AHRENDT MR

    2009-08-11

    Since this report was originally issued in 2001, several options proposed for increasing double-shell tank (DST) storage space were implemented or are in the process of implementation. Changes to the single-shell tank (SST) waste retrieval schedule, completion of DST space saving options, and the DST space saving options in progress have delayed the projected shortfall of DST storage space from the 2007-2011 to the 2018-2025 timeframe (ORP-11242, River Protection Project System Plan). This report reevaluates options from Rev. 0 and includes evaluations of new options for alleviating projected restrictions on SST waste retrieval beginning in 2018 because of the lack of DST storage space.

  2. National Aeronautical and Space Administration (NASA) Johnson Space Flight

    Office of Environmental Management (EM)

    Center | Department of Energy Aeronautical and Space Administration (NASA) Johnson Space Flight Center National Aeronautical and Space Administration (NASA) Johnson Space Flight Center Space Shuttle Endeavour, 2002 The NASA Johnson Space Flight Center in Houston is well known for its achievements in the U.S. space program (this 2002 photo shows the Space Shuttle Endeavour on its way to the International Space Station). Overview NASA will save approximately $43 million in facility operations

  3. THE FIRST OBSERVATIONS OF LOW-REDSHIFT DAMPED Ly{alpha} SYSTEMS WITH THE COSMIC ORIGINS SPECTROGRAPH: CHEMICAL ABUNDANCES AND AFFILIATED GALAXIES

    SciTech Connect (OSTI)

    Battisti, A. J.; Meiring, J. D.; Tripp, T. M. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Prochaska, J. X.; Werk, J. K. [Department of Astronomy and Astrophysics, University of California Observatories-Lick Observatory, UC Santa Cruz, CA 95064 (United States); Jenkins, E. B. [Department of Astrophysical Sciences, Princeton University Observatory, Princeton, NJ 08544 (United States); Lehner, N. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Tumlinson, J.; Thom, C. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2012-01-10

    We present Cosmic Origins Spectrograph (COS) measurements of metal abundances in eight 0.083 < z{sub abs} < 0.321 damped Ly{alpha} (DLA) and sub-DLA absorption systems serendipitously discovered in the COS-Halos survey. We find that these systems show a large range in metallicities, with -1.10 < [Z/H] < 0.31, similar to the spread found at higher redshifts. These low-redshift systems on average have subsolar metallicities, but do show a rise in metallicity over cosmic time when compared to higher-redshift systems. We find that the average sub-DLA metallicity is higher than the average DLA metallicity at all redshifts. Nitrogen is underabundant with respect to {alpha}-group elements in all but perhaps one of the absorbers. In some cases, [N/{alpha}] is significantly below the lowest nitrogen measurements in nearby galaxies. Systems for which depletion patterns can be studied show little, if any, depletion, which is characteristic of Milky Way halo-type gas. We also identify affiliated galaxies for three of the sub-DLAs using spectra obtained from a Keck/Low Resolution Imaging Spectrometer (LRIS). None of these sub-DLAs arise in the stellar disks of luminous galaxies; instead, these absorbers may exist in galaxy halos at impact parameters ranging from 38 to 92 kpc. Multiple galaxies are present near two of the sub-DLAs, and galaxy interactions may play a role in the dispersal of the gas. Many of these low-redshift absorbers exhibit simple kinematics, but one sub-DLA has a complicated mix of at least 13 components spread over 150 km s{sup -1}. We find three galaxies near this sub-DLA, which also suggests that galaxy interactions roil the gas. This study reinforces the view that DLAs have a variety of origins, and low-redshift studies are crucial for understanding absorber-galaxy connections.

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

    SciTech Connect (OSTI)

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

    2010-01-01

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

  5. Earth, Space Sciences

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

    Earth, Space Sciences /science-innovation/_assets/images/icon-science.jpg Earth, Space Sciences National security depends on science and technology. The United States relies on Los Alamos National Laboratory for the best of both. No place on Earth pursues a broader array of world-class scientific endeavors. Climate, Ocean and Sea Ice Modeling (COSIM)» Earth and Environmental Sciences Division» Intelligence and Space Research» Earth Read caption + A team of scientists is working to understand

  6. Passive solar space heating

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1980-01-01

    An overview of passive solar space heating is presented indicating trends in design, new developments, performance measures, analytical design aids, and monitored building results.

  7. Berkeley Lab Space

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

    Space Committee Charter Articles Presentations Feedback Contact Us ANNOUNCEMENTS Feb. 13, 2014 Courtesy Salvage Pickup Factsheet To assist the community in disposing of "no longer...

  8. Total Space Heat-

    Gasoline and Diesel Fuel Update (EIA)

    Commercial Buildings Energy Consumption Survey: Energy End-Use Consumption Tables Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration...

  9. Total Space Heat-

    Gasoline and Diesel Fuel Update (EIA)

    Revised: December, 2008 Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other All Buildings...

  10. Total Space Heat-

    Gasoline and Diesel Fuel Update (EIA)

    Released: September, 2008 Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other All Buildings*...

  11. Strong focus space charge

    DOE Patents [OSTI]

    Booth, Rex (Livermore, CA)

    1981-01-01

    Strong focus space charge lens wherein a combination of current-carrying coils and charged electrodes form crossed magnetic and electric fields to focus charged particle beams.

  12. HERSCHEL-ATLAS GALAXY COUNTS AND HIGH-REDSHIFT LUMINOSITY FUNCTIONS: THE FORMATION OF MASSIVE EARLY-TYPE GALAXIES

    SciTech Connect (OSTI)

    Lapi, A.; Gonzalez-Nuevo, J.; Fan, L.; Bressan, A.; De Zotti, G.; Danese, L.; Negrello, M.; Dunne, L.; Maddox, S.; Eales, S.; Auld, R.; Dariush, A.; Dye, S.; Baes, M.; Fritz, J.; Bonfield, D. G.; Buttiglione, S.; Cava, A.; Clements, D. L.; Cooray, A.

    2011-11-20

    Exploiting the Herschel Astrophysical Terahertz Large Area Survey Science Demonstration Phase survey data, we have determined the luminosity functions (LFs) at rest-frame wavelengths of 100 and 250 {mu}m and at several redshifts z {approx}> 1, for bright submillimeter galaxies with star formation rates (SFRs) {approx}> 100 M{sub Sun} yr{sup -1}. We find that the evolution of the comoving LF is strong up to z Almost-Equal-To 2.5, and slows down at higher redshifts. From the LFs and the information on halo masses inferred from clustering analysis, we derived an average relation between SFR and halo mass (and its scatter). We also infer that the timescale of the main episode of dust-enshrouded star formation in massive halos (M{sub H} {approx}> 3 Multiplication-Sign 10{sup 12} M{sub Sun }) amounts to {approx}7 Multiplication-Sign 10{sup 8} yr. Given the SFRs, which are in the range of 10{sup 2}-10{sup 3} M{sub Sun} yr{sup -1}, this timescale implies final stellar masses of the order of 10{sup 11}-10{sup 12} M{sub Sun }. The corresponding stellar mass function matches the observed mass function of passively evolving galaxies at z {approx}> 1. The comparison of the statistics for submillimeter and UV-selected galaxies suggests that the dust-free, UV bright phase is {approx}> 10{sup 2} times shorter than the submillimeter bright phase, implying that the dust must form soon after the onset of star formation. Using a single reference spectral energy distribution (SED; the one of the z Almost-Equal-To 2.3 galaxy SMM J2135-0102), our simple physical model is able to reproduce not only the LFs at different redshifts >1 but also the counts at wavelengths ranging from 250 {mu}m to Almost-Equal-To 1 mm. Owing to the steepness of the counts and their relatively broad frequency range, this result suggests that the dispersion of submillimeter SEDs of z > 1 galaxies around the reference one is rather small.

  13. CRITICAL STAR FORMATION RATES FOR REIONIZATION: FULL REIONIZATION OCCURS AT REDSHIFT z Almost-Equal-To 7

    SciTech Connect (OSTI)

    Michael Shull, J.; Harness, Anthony; Trenti, Michele; Smith, Britton D. E-mail: trenti@colorado.edu E-mail: smit1685@msu.edu

    2012-03-10

    We assess the probable redshift (z{sub rei} Almost-Equal-To 7) for full reionization of the intergalactic medium (IGM) using a prescription for the comoving star formation rate (SFR) density ({rho}-dot{sub SFR}) required to maintain photoionization against recombination. Our newly developed online reionization simulator allows users to assess the required SFR and ionization histories, using a variety of assumptions for galactic and stellar populations, IGM clumping factor and temperature, and Lyman continuum (LyC) escape fraction. The decline in high-redshift galaxy candidates and Ly{alpha} emitters at z = 6-8 suggests a rising neutral fraction, with reionization at z {approx}> 7 increasingly difficult owing to increased recombination rates and constraints from the ionizing background and LyC mean free path. The required rate is {rho}-dot{sub SFR}{approx}(.018 M{sub sun}yr{sup -1}Mpc{sup -3})[(1+z)/8]{sup 3}(C{sub H}/3)(0.2/f{sub esc})T{sub 4}{sup -0.845} scaled to fiducial values of clumping factor C{sub H} = 3, escape fraction f{sub esc} = 0.2, electron temperature T{sub e} = 10{sup 4} K, and low-metallicity initial mass functions (IMFs) and stellar atmospheres. Our hydrodynamical + N-body simulations find a mean clumping factor C{sub H} Almost-Equal-To (2.9)[(1 + z)/6]{sup -1.1} in the photoionized, photoheated filaments at z = 5-9. The critical SFR could be reduced by increasing the minimum stellar mass, invoking a top-heavy IMF, or systematically increasing f{sub esc} at high z. The cosmic microwave background optical depth, {tau}{sub e} = 0.088 {+-} 0.015, could be explained by full reionization, producing {tau}{sub e} = 0.050 back to z{sub rei} Almost-Equal-To 7, augmented by {Delta}{tau}{sub e} Almost-Equal-To 0.01-0.04 in a partially ionized IGM at z > 7. In this scenario, the strongest 21 cm signal should occur at redshifted frequencies 124-167 MHz owing to IGM heating over an interval {Delta}z Almost-Equal-To 3 in the range z Almost-Equal-To 7.5-10.5.

  14. UNDERSTANDING PHYSICAL CONDITIONS IN HIGH-REDSHIFT GALAXIES THROUGH C I FINE STRUCTURE LINES: DATA AND METHODOLOGY

    SciTech Connect (OSTI)

    Jorgenson, Regina A.; Wolfe, Arthur M.; Prochaska, J. Xavier

    2010-10-10

    We probe the physical conditions in high-redshift galaxies, specifically, the damped Ly{alpha} systems (DLAs) using neutral carbon (C I) fine structure lines and molecular hydrogen (H{sub 2}). We report five new detections of C I and analyze the C I in an additional two DLAs with previously published data. We also present one new detection of H{sub 2} in a DLA. We present a new method of analysis that simultaneously constrains both the volume density and the temperature of the gas, as opposed to previous studies that a priori assumed a gas temperature. We use only the column density of C I measured in the fine structure states and the assumption of ionization equilibrium in order to constrain the physical conditions in the gas. We present a sample of 11 C I velocity components in six DLAs and compare their properties to those derived by the global C II* technique. The resulting median values for this sample are (n(H I)) = 69 cm{sup -3}, (T) = 50 K, and (log(P/k)) = 3.86 cm{sup -3} K, with standard deviations, {sigma}{sub n(H{sub i})} = 134 cm{sup -3}, {sigma}{sub T} = 52 K, and {sigma}{sub log(P/k)} = 3.68 cm{sup -3} K. This can be compared with the integrated median values for the same DLAs: (n(H I)) = 2.8 cm{sup -3}, (T) = 139 K, and (log(P/k)) = 2.57 cm{sup -3} K, with standard deviations {sigma}{sub n(H{sub i})} = 3.0 cm{sup -3}, {sigma}{sub T} = 43 K, and {sigma}{sub log(P/k)} = 0.22 cm{sup -3} K. Interestingly, the pressures measured in these high-redshift C I clouds are similar to those found in the Milky Way. We conclude that the C I gas is tracing a higher-density, higher-pressure region, possibly indicative of post-shock gas or a photodissociation region on the edge of a molecular cloud. We speculate that these clouds may be direct probes of the precursor sites of star formation in normal galaxies at high redshift.

  15. Space Week | Department of Energy

    Energy Savers [EERE]

    Space Week Space Week Space Week Preventing Space Traffic Jams With around one thousand active satellites and the tens of thousands of pieces of space junk orbiting Earth, space is getting exceedingly crowded. Researchers at Lawrence Livermore National Lab are working on a system that could help prevent collisions in space. | Graphic by <a href="/node/379579">Sarah Gerrity</a>, Energy Department. With space getting exceedingly crowded, researchers at Lawrence Livermore

  16. Space Week | Department of Energy

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

    Space Week Space Week Space Week Preventing Space Traffic Jams With around one thousand active satellites and the tens of thousands of pieces of space junk orbiting Earth, space is getting exceedingly crowded. Researchers at Lawrence Livermore National Lab are working on a system that could help prevent collisions in space. | Graphic by <a href="/node/379579">Sarah Gerrity</a>, Energy Department. With space getting exceedingly crowded, researchers at Lawrence Livermore

  17. The effect of large amplitude motions on the transition frequency redshift in hydrogen bonded complexes: A physical picture

    SciTech Connect (OSTI)

    Mackeprang, Kasper; Kjaergaard, Henrik G.; Salmi, Teemu; Hnninen, Vesa; Halonen, Lauri

    2014-05-14

    We describe the vibrational transitions of the donor unit in water dimer with an approach that is based on a three-dimensional local mode model. We perform a perturbative treatment of the intermolecular vibrational modes to improve the transition wavenumber of the hydrogen bonded OH-stretching transition. The model accurately predicts the transition wavenumbers of the vibrations in water dimer compared to experimental values and provides a physical picture that explains the redshift of the hydrogen bonded OH-oscillator. We find that it is unnecessary to include all six intermolecular modes in the vibrational model and that their effect can, to a good approximation, be computed using a potential energy surface calculated at a lower level electronic structure method than that used for the unperturbed model.

  18. DEEP SPITZER OBSERVATIONS OF INFRARED-FAINT RADIO SOURCES: HIGH-REDSHIFT RADIO-LOUD ACTIVE GALACTIC NUCLEI?

    SciTech Connect (OSTI)

    Norris, Ray P.; Mao, Minnie; Afonso, Jose; Cava, Antonio; Farrah, Duncan; Oliver, Seb; Huynh, Minh T.; Mauduit, Jean-Christophe; Surace, Jason; Ivison, R. J.; Jarvis, Matt; Lacy, Mark; Maraston, Claudia; Middelberg, Enno; Seymour, Nick

    2011-07-20

    Infrared-faint radio sources (IFRSs) are a rare class of objects which are relatively bright at radio wavelengths but very faint at infrared and optical wavelengths. Here we present sensitive near-infrared observations of a sample of these sources taken as part of the Spitzer Extragalactic Representative Volume Survey. Nearly all the IFRSs are undetected at a level of {approx}1 {mu}Jy in these new deep observations, and even the detections are consistent with confusion with unrelated galaxies. A stacked image implies that the median flux density is S{sub 3.6{mu}m} {approx} 0.2 {mu}Jy or less, giving extreme values of the radio-infrared flux density ratio. Comparison of these objects with known classes of object suggests that the majority are probably high-redshift radio-loud galaxies, possibly suffering from significant dust extinction.

  19. MEASURING THE ULTIMATE HALO MASS OF GALAXY CLUSTERS: REDSHIFTS AND MASS PROFILES FROM THE HECTOSPEC CLUSTER SURVEY (HeCS)

    SciTech Connect (OSTI)

    Rines, Kenneth; Geller, Margaret J.; Kurtz, Michael J.; Diaferio, Antonaldo E-mail: diaferio@ph.unito.it

    2013-04-10

    The infall regions of galaxy clusters represent the largest gravitationally bound structures in a {Lambda}CDM universe. Measuring cluster mass profiles into the infall regions provides an estimate of the ultimate mass of these halos. We use the caustic technique to measure cluster mass profiles from galaxy redshifts obtained with the Hectospec Cluster Survey (HeCS), an extensive spectroscopic survey of galaxy clusters with MMT/Hectospec. We survey 58 clusters selected by X-ray flux at 0.1 < z < 0.3. The survey includes 22,680 unique MMT/Hectospec redshifts for individual galaxies; 10,145 of these galaxies are cluster members. For each cluster, we acquired high signal-to-noise spectra for {approx}200 cluster members and a comparable number of foreground/background galaxies. The cluster members trace out infall patterns around the clusters. The members define a very narrow red sequence. We demonstrate that the determination of velocity dispersion is insensitive to the inclusion of bluer members (a small fraction of the cluster population). We apply the caustic technique to define membership and estimate the mass profiles to large radii. The ultimate halo mass of clusters (the mass that remains bound in the far future of a {Lambda}CDM universe) is on average (1.99 {+-} 0.11)M{sub 200}, a new observational cosmological test in essential agreement with simulations. Summed profiles binned in M{sub 200} and in L{sub X} demonstrate that the predicted Navarro-Frenk-White form of the density profile is a remarkably good representation of the data in agreement with weak lensing results extending to large radius. The concentration of these summed profiles is also consistent with theoretical predictions.

  20. THERMAL AND RADIATIVE ACTIVE GALACTIC NUCLEUS FEEDBACK HAVE A LIMITED IMPACT ON STAR FORMATION IN HIGH-REDSHIFT GALAXIES

    SciTech Connect (OSTI)

    Roos, Orianne; Juneau, Stphanie; Bournaud, Frdric; Gabor, Jared M.

    2015-02-10

    The effects of active galactic nuclei (AGNs) on their host galaxies depend on the coupling between the injected energy and the interstellar medium (ISM). Here, we model and quantify the impact of long-range AGN ionizing radiationin addition to the often considered small-scale energy depositionon the physical state of the multi-phase ISM of the host galaxy and on its total star formation rate (SFR). We formulate an AGN spectral energy distribution matched with observations, which we use with the radiative transfer (RT) code Cloudy to compute AGN ionization in a simulated high-redshift disk galaxy. We use a high-resolution (?6 pc) simulation including standard thermal AGN feedback and calculate RT in post-processing. Surprisingly, while these models produce significant AGN-driven outflows, we find that AGN ionizing radiation and heating reduce the SFR by a few percent at most for a quasar luminosity (L {sub bol} = 10{sup 46.5} erg s{sup 1}). Although the circumgalactic gaseous halo can be kept almost entirely ionized by the AGN, most star-forming clouds (n ? 10{sup 2} {sup } {sup 3} cm{sup 3}) and even the reservoirs of cool atomic gas (n ? 0.3-10 cm{sup 3})which are the sites of future star formation (SF; 100-200 Myr), are generally too dense to be significantly affected. Our analysis ignores any absorption from a putative torus, making our results upper limits on the effects of ionizing radiation. Therefore, while the AGN-driven outflows can remove substantial amounts of gas in the long term, the impact of AGN feedback on the SF efficiency in the interstellar gas in high-redshift galaxies is marginal, even when long-range radiative effects are accounted for.

  1. Atoms for space

    SciTech Connect (OSTI)

    Buden, D.

    1990-10-01

    Nuclear technology offers many advantages in an expanded solar system space exploration program. These cover a range of possible applications such as power for spacecraft, lunar and planetary surfaces, and electric propulsion; rocket propulsion for lunar and Mars vehicles; space radiation protection; water and sewage treatment; space mining; process heat; medical isotopes; and self-luminous systems. In addition, space offers opportunities to perform scientific research and develop systems that can solve problems here on Earth. These might include fusion and antimatter research, using the Moon as a source of helium-3 fusion fuel, and manufacturing perfect fusion targets. In addition, nuclear technologies can be used to reduce risk and costs of the Space Exploration Initiative. 1 fig.

  2. The 'virtual density' principle of neutronics: Toward rapid computation of reactivity effects in practical core distortion scenarios

    SciTech Connect (OSTI)

    Reed, M.; Smith, K.; Forget, B.

    2013-07-01

    Fast reactor core reactivities are sensitive to geometric distortions arising from three distinct phenomena: (1) irradiation swelling of fuel throughout core lifetime, (2) thermal expansion of fuel during transients, and (3) mechanical oscillations during seismic events. Performing comprehensive reactivity analysis of these distortions requires methods for rapidly computing a multitude of minute reactivity changes. Thus, we introduce the 'virtual density' principle of neutronics as a new perturbation technique to achieve this rapid computation. This new method obviates many of the most challenging aspects of conventional geometric perturbation theory. Essentially, this 'virtual density' principle converts geometric perturbations into equivalent material density perturbations (either isotropic or anisotropic), which are highly accurate and comparatively simple to evaluate. While traditional boundary perturbation theory employs surface integrals, the 'virtual density' principle employs equivalent volume integrals. We introduce and validate this method in three subsequent stages: (1) isotropic 'virtual density', (2) anisotropic 'virtual density' for whole cores, and (3) anisotropic 'virtual density' for interior zones within cores. We numerically demonstrate its accuracy for 2-D core flowering scenarios. (authors)

  3. Tidally distorted exoplanets: Density corrections for short-period hot-Jupiters based solely on observable parameters

    SciTech Connect (OSTI)

    Burton, J. R.; Watson, C. A.; Fitzsimmons, A.; Moulds, V.; Pollacco, D.; Wheatley, P. J.; Littlefair, S. P.

    2014-07-10

    The close proximity of short-period hot-Jupiters to their parent star means they are subject to extreme tidal forces. This has a profound effect on their structure and, as a result, density measurements that assume that the planet is spherical can be incorrect. We have simulated the tidally distorted surface for 34 known short-period hot-Jupiters, assuming surfaces of constant gravitational equipotential for the planet, and the resulting densities have been calculated based only on observed parameters of the exoplanet systems. Comparing these results to the density values, assuming the planets are spherical, shows that there is an appreciable change in the measured density for planets with very short periods (typically less than two days). For one of the shortest-period systems, WASP-19b, we determine a decrease in bulk density of 12% from the spherical case and, for the majority of systems in this study, this value is in the range of 1%-5%. On the other hand, we also find cases where the distortion is negligible (relative to the measurement errors on the planetary parameters) even in the cases of some very short period systems, depending on the mass ratio and planetary radius. For high-density gas planets requiring apparently anomalously large core masses, density corrections due to tidal deformation could become important for the shortest-period systems.

  4. Anti-hierarchical evolution of the active galactic nucleus space density in a hierarchical universe

    SciTech Connect (OSTI)

    Enoki, Motohiro; Ishiyama, Tomoaki; Kobayashi, Masakazu A. R.; Nagashima, Masahiro

    2014-10-10

    Recent observations show that the space density of luminous active galactic nuclei (AGNs) peaks at higher redshifts than that of faint AGNs. This downsizing trend in the AGN evolution seems to be contradictory to the hierarchical structure formation scenario. In this study, we present the AGN space density evolution predicted by a semi-analytic model of galaxy and AGN formation based on the hierarchical structure formation scenario. We demonstrate that our model can reproduce the downsizing trend of the AGN space density evolution. The reason for the downsizing trend in our model is a combination of the cold gas depletion as a consequence of star formation, the gas cooling suppression in massive halos, and the AGN lifetime scaling with the dynamical timescale. We assume that a major merger of galaxies causes a starburst, spheroid formation, and cold gas accretion onto a supermassive black hole (SMBH). We also assume that this cold gas accretion triggers AGN activity. Since the cold gas is mainly depleted by star formation and gas cooling is suppressed in massive dark halos, the amount of cold gas accreted onto SMBHs decreases with cosmic time. Moreover, AGN lifetime increases with cosmic time. Thus, at low redshifts, major mergers do not always lead to luminous AGNs. Because the luminosity of AGNs is correlated with the mass of accreted gas onto SMBHs, the space density of luminous AGNs decreases more quickly than that of faint AGNs. We conclude that the anti-hierarchical evolution of the AGN space density is not contradictory to the hierarchical structure formation scenario.

  5. Mass calibration of galaxy clusters at redshift 0.11.0 using weak lensing in the Sloan Digital Sky Survey Stripe 82 co-add

    SciTech Connect (OSTI)

    Wiesner, Matthew P.; Lin, Huan; Soares-Santos, Marcelle

    2015-07-08

    We present galaxy cluster massrichness relations found in the Sloan Digital Sky Survey Stripe 82 co-add using clusters found using a Voronoi tessellation cluster finder. These relations were found using stacked weak lensing shear observed in a large sample of galaxy clusters. These massrichness relations are presented for four redshift bins, 0.1 < z ? 0.4, 0.4 < z ? 0.7, 0.7 < z ? 1.0 and 0.1 < z ? 1.0. We describe the sample of galaxy clusters and explain how these clusters were found using a Voronoi tessellation cluster finder. We fit a Navarro-Frenk-White profile to the stacked weak lensing shear signal in redshift and richness bins in order to measure virial mass (M200). We describe several effects that can bias weak lensing measurements, including photometric redshift bias, the effect of the central BCG, halo miscentering, photometric redshift uncertainty and foreground galaxy contamination. We present massrichness relations using richness measure NVT with each of these effects considered separately as well as considered altogether. We also examine redshift evolution of the massrichness relation. As a result, we present measurements of the mass coefficient (M200|20) and the power-law slope (?) for power-law fits to the mass and richness values in each of the redshift bins. We find values of the mass coefficient of 8.49 0.526, 14.1 1.78, 30.2 8.74 and 9.23 0.525 1013 h1 M? for each of the four redshift bins, respectively. As a result, we find values of the power-law slope of 0.905 0.0585, 0.948 0.100, 1.33 0.260 and 0.883 0.0500, respectively.

  6. Mass calibration of galaxy clusters at redshift 0.1–1.0 using weak lensing in the Sloan Digital Sky Survey Stripe 82 co-add

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

    Wiesner, Matthew P.; Lin, Huan; Soares-Santos, Marcelle

    2015-07-08

    We present galaxy cluster mass–richness relations found in the Sloan Digital Sky Survey Stripe 82 co-add using clusters found using a Voronoi tessellation cluster finder. These relations were found using stacked weak lensing shear observed in a large sample of galaxy clusters. These mass–richness relations are presented for four redshift bins, 0.1 < z ≤ 0.4, 0.4 < z ≤ 0.7, 0.7 < z ≤ 1.0 and 0.1 < z ≤ 1.0. We describe the sample of galaxy clusters and explain how these clusters were found using a Voronoi tessellation cluster finder. We fit a Navarro-Frenk-White profile to the stackedmore » weak lensing shear signal in redshift and richness bins in order to measure virial mass (M200). We describe several effects that can bias weak lensing measurements, including photometric redshift bias, the effect of the central BCG, halo miscentering, photometric redshift uncertainty and foreground galaxy contamination. We present mass–richness relations using richness measure NVT with each of these effects considered separately as well as considered altogether. We also examine redshift evolution of the mass–richness relation. As a result, we present measurements of the mass coefficient (M200|20) and the power-law slope (α) for power-law fits to the mass and richness values in each of the redshift bins. We find values of the mass coefficient of 8.49 ± 0.526, 14.1 ± 1.78, 30.2 ± 8.74 and 9.23 ± 0.525 × 1013 h–1 M⊙ for each of the four redshift bins, respectively. As a result, we find values of the power-law slope of 0.905 ± 0.0585, 0.948 ± 0.100, 1.33 ± 0.260 and 0.883 ± 0.0500, respectively.« less

  7. The DAFT/FADA survey. I.Photometric redshifts along lines of sight to clusters in the z=[0.4,0.9] interval

    SciTech Connect (OSTI)

    Guennou, L.; Adami, C.; Ulmer, M.P.; LeBrun, V.; Durret, F.; Johnston, D.; Ilbert, O.; Clowe, D.; Gavazzi, R.; Murphy, K.; Schrabback, T.; /Leiden Observ. /Fermilab

    2010-08-01

    As a contribution to the understanding of the dark energy concept, the Dark energy American French Team (DAFT, in French FADA) has started a large project to characterize statistically high redshift galaxy clusters, infer cosmological constraints from Weak Lensing Tomography, and understand biases relevant for constraining dark energy and cluster physics in future cluster and cosmological experiments. Aims. The purpose of this paper is to establish the basis of reference for the photo-z determination used in all our subsequent papers, including weak lensing tomography studies. This project is based on a sample of 91 high redshift (z {ge} 0.4), massive ({approx}> 3 x 10{sup 14} M{sub {circle_dot}}) clusters with existing HST imaging, for which we are presently performing complementary multi-wavelength imaging. This allows us in particular to estimate spectral types and determine accurate photometric redshifts for galaxies along the lines of sight to the first ten clusters for which all the required data are available down to a limit of I{sub AB} = 24./24.5 with the LePhare software. The accuracy in redshift is of the order of 0.05 for the range 0.2 {le} z {le} 1.5. We verified that the technique applied to obtain photometric redshifts works well by comparing our results to with previous works. In clusters, photo-z accuracy is degraded for bright absolute magnitudes and for the latest and earliest type galaxies. The photo-z accuracy also only slightly varies as a function of the spectral type for field galaxies. As a consequence, we find evidence for an environmental dependence of the photo-z accuracy, interpreted as the standard used Spectral Energy Distributions being not very well suited to cluster galaxies. Finally, we modeled the LCDCS 0504 mass with the strong arcs detected along this line of sight.

  8. Total Space Heat-

    Gasoline and Diesel Fuel Update (EIA)

    Survey: Energy End-Use Consumption Tables Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration Office Equip- ment Com- puters Other...

  9. Nuclear Power in Space

    DOE R&D Accomplishments [OSTI]

    1994-01-01

    In the early years of the United States space program, lightweight batteries, fuel cells, and solar modules provided electric power for space missions. As missions became more ambitious and complex, power needs increased and scientists investigated various options to meet these challenging power requirements. One of the options was nuclear energy. By the mid-1950s, research had begun in earnest on ways to use nuclear power in space. These efforts resulted in the first radioisotope thermoelectric generators (RTGs), which are nuclear power generators build specifically for space and special terrestrial uses. These RTGs convert the heat generated from the natural decay of their radioactive fuel into electricity. RTGs have powered many spacecraft used for exploring the outer planets of the solar system and orbiting the sun and Earth. They have also landed on Mars and the moon. They provide the power that enables us to see and learn about even the farthermost objects in our solar system.

  10. Intelligence and Space Research

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

    ISR Intelligence and Space Research Create, deliver, support, and exploit innovative sensing systems for space-based, airborne and ground-based applications to address critical national security and scientific challenges Leadership Division Leader Kevin Saeger Deputy Division Leader Angela Mielke Contacts Chief of Staff Aimee Blanchard Email Executive Office Administrator Mary T. Wubbena Email Create, deliver, support and exploit innovative sensing systems Innovative sensing systems for

  11. A study of astrometric distortions due to “tree rings” in CCD sensors using LSST Photon Simulator

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

    Beamer, Benjamin; Nomerotski, Andrei; Tsybychev, Dmitri

    2015-05-22

    Imperfections in the production process of thick CCDs lead to circularly symmetric dopant concentration variations, which in turn produce electric fields transverse to the surface of the fully depleted CCD that displace the photogenerated charges. We use PhoSim, a Monte Carlo photon simulator, to explore and examine the likely impacts these dopant concentration variations will have on astrometric measurements in LSST. The scale and behavior of both the astrometric shifts imparted to point sources and the intensity variations in flat field images that result from these doping imperfections are similar to those previously observed in Dark Energy Camera CCDs, givingmore » initial confirmation of PhoSim's model for these effects. In addition, the organized shape distortions were observed as a result of the symmetric nature of these dopant variations, causing nominally round sources to be imparted with a measurable ellipticity either aligned with or transverse to the radial direction of this dopant variation pattern.« less

  12. Space Managment | The Ames Laboratory

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

    Space Managment Space Utilization The Space Utilization report is required by DOE-CH and provides the most up-to-date information on room use by the Laboratory. The current version can be obtained from Tom Lograsso, Deputy Director.

  13. Space Instrument Realization (ISR-5)

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

    5 Space Instrument Realization Providing expertise to support the design and fabrication of space-based custom instrumentation Contacts Group Leader Amy Regan Email Staff...

  14. IMPROVED MOCK GALAXY CATALOGS FOR THE DEEP2 GALAXY REDSHIFT SURVEY FROM SUBHALO ABUNDANCE AND ENVIRONMENT MATCHING

    SciTech Connect (OSTI)

    Gerke, Brian F.; Wechsler, Risa H.; Behroozi, Peter S.; Yan, Renbin; Coil, Alison L.

    2013-09-15

    We develop empirical methods for modeling the galaxy population and populating cosmological N-body simulations with mock galaxies according to the observed properties of galaxies in survey data. We use these techniques to produce a new set of mock catalogs for the DEEP2 Galaxy Redshift Survey based on the output of the high-resolution Bolshoi simulation, as well as two other simulations with different cosmological parameters, all of which we release for public use. The mock-catalog creation technique uses subhalo abundance matching to assign galaxy luminosities to simulated dark-matter halos. It then adds color information to the resulting mock galaxies in a manner that depends on the local galaxy density, in order to reproduce the measured color-environment relation in the data. In the course of constructing the catalogs, we test various models for including scatter in the relation between halo mass and galaxy luminosity, within the abundance-matching framework. We find that there is no constant-scatter model that can simultaneously reproduce both the luminosity function and the autocorrelation function of DEEP2. This result has implications for galaxy-formation theory, and it restricts the range of contexts in which the mock catalogs can be usefully applied. Nevertheless, careful comparisons show that our new mock catalogs accurately reproduce a wide range of the other properties of the DEEP2 catalog, suggesting that they can be used to gain a detailed understanding of various selection effects in DEEP2.

  15. Hunting space rocks

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

    Hunting space rocks Hunting space rocks Nina Lanza is studying the solar system by spending six weeks on an ice sheet in Antarctica. The 36-year-old staff scientist at the Los Alamos National Laboratory in New Mexico is on a treasure hunt of sorts. January 15, 2016 Nina Lanza Nina Lanza is part of a team driving across the Trans-Antarctica Mountains on snowmobiles in search of meteorites. (Courtesy of Nina Lanza) "One of the most interesting things from meteorites is every rocky body has a

  16. ON THE DETECTION OF IONIZING RADIATION ARISING FROM STAR-FORMING GALAXIES AT REDSHIFT z {approx} 3-4: LOOKING FOR ANALOGS OF 'STELLAR RE-IONIZERS'

    SciTech Connect (OSTI)

    Vanzella, Eros; Cristiani, Stefano; Nonino, Mario; Guo Yicheng; Giavalisco, Mauro; Grazian, Andrea; Castellano, Marco; Fontana, Adriano; Giallongo, Emanuele; Pentericci, Laura; Galametz, Audrey; Dickinson, Mark; Faber, S. M.; Newman, Jeffrey; Siana, Brian D.

    2012-05-20

    We use the spatially resolved, multi-band photometry in the GOODS South field acquired by the CANDELS project to constrain the nature of candidate Lyman continuum (LyC) emitters at redshift z {approx} 3.7 identified using ultradeep imaging below the Lyman limit (1{sigma} limit of Almost-Equal-To 30 AB in a 2'' diameter aperture). In 19 candidates out of a sample of 20 with flux detected at >3{sigma} level, the light centroid of the candidate LyC emission is offset from that of the Lyman break galaxy (LBG) by up to 1.''5. We fit the spectral energy distribution of the LyC candidates to spectral population synthesis models to measure photometric redshifts and the stellar population parameters. We also discuss the differences in the UV colors between the LBG and the LyC candidates, and how to estimate the escape fraction of ionizing radiation (f{sub esc}) in cases, like in most of our galaxies, where the LyC emission is spatially offset from the host galaxy. In all but one case we conclude that the candidate LyC emission is most likely due to lower redshift interlopers. Based on these findings, we argue that the majority of similar measurements reported in the literature need further investigation before it can be firmly concluded that LyC emission is detected. Our only surviving LyC candidate is an LBG at z = 3.795, which shows the bluest (B - V) color among LBGs at similar redshift, a stellar mass of M {approx} 2 Multiplication-Sign 10{sup 9} M{sub Sun }, weak interstellar absorption lines, and a flat UV spectral slope with no Ly{alpha} in emission. We estimate its f{sub esc} to be in the range 25%-100%, depending on the dust and intergalactic attenuation.

  17. Semantic Space Analyst

    Energy Science and Technology Software Center (OSTI)

    2004-04-15

    The Semantic Space Analyst (SSA) is software for analyzing a text corpus, discovering relationships among terms, and allowing the user to explore that information in different ways. It includes features for displaying and laying out terms and relationships visually, for generating such maps from manual queries, for discovering differences between corpora. Data can also be exported to Microsoft Excel.

  18. A cascaded model of spectral distortions due to spectral response effects and pulse pileup effects in a photon-counting x-ray detector for CT

    SciTech Connect (OSTI)

    Cammin, Jochen E-mail: ktaguchi@jhmi.edu; Taguchi, Katsuyuki E-mail: ktaguchi@jhmi.edu; Xu, Jennifer; Barber, William C.; Iwanczyk, Jan S.; Hartsough, Neal E.

    2014-04-15

    Purpose: Energy discriminating, photon-counting detectors (PCDs) are an emerging technology for computed tomography (CT) with various potential benefits for clinical CT. The photon energies measured by PCDs can be distorted due to the interactions of a photon with the detector and the interaction of multiple coincident photons. These effects result in distorted recorded x-ray spectra which may lead to artifacts in reconstructed CT images and inaccuracies in tissue identification. Model-based compensation techniques have the potential to account for the distortion effects. This approach requires only a small number of parameters and is applicable to a wide range of spectra and count rates, but it needs an accurate model of the spectral distortions occurring in PCDs. The purpose of this study was to develop a model of those spectral distortions and to evaluate the model using a PCD (model DXMCT-1; DxRay, Inc., Northridge, CA) and various x-ray spectra in a wide range of count rates. Methods: The authors hypothesize that the complex phenomena of spectral distortions can be modeled by: (1) separating them into count-rate independent factors that we call the spectral response effects (SRE), and count-rate dependent factors that we call the pulse pileup effects (PPE), (2) developing separate models for SRE and PPE, and (3) cascading the SRE and PPE models into a combined SRE+PPE model that describes PCD distortions at both low and high count rates. The SRE model describes the probability distribution of the recorded spectrum, with a photo peak and a continuum tail, given the incident photon energy. Model parameters were obtained from calibration measurements with three radioisotopes and then interpolated linearly for other energies. The PPE model used was developed in the authors previous work [K. Taguchi et al., Modeling the performance of a photon counting x-ray detector for CT: Energy response and pulse pileup effects, Med. Phys. 38(2), 10891102 (2011)]. The agreement between the x-ray spectra calculated by the cascaded SRE+PPE model and the measured spectra was evaluated for various levels of deadtime loss ratios (DLR) and incident spectral shapes, realized using different attenuators, in terms of the weighted coefficient of variation (COV{sub W}), i.e., the root mean square difference weighted by the statistical errors of the data and divided by the mean. Results: At low count rates, when DLR < 10%, the distorted spectra measured by the DXMCT-1 were in agreement with those calculated by SRE only, with COV{sub W}'s less than 4%. At higher count rates, the measured spectra were also in agreement with the ones calculated by the cascaded SRE+PPE model; with PMMA as attenuator, COV{sub W} was 5.6% at a DLR of 22% and as small as 6.7% for a DLR as high as 55%. Conclusions: The x-ray spectra calculated by the proposed model agreed with the measured spectra over a wide range of count rates and spectral shapes. The SRE model predicted the distorted, recorded spectra with low count rates over various types and thicknesses of attenuators. The study also validated the hypothesis that the complex spectral distortions in a PCD can be adequately modeled by cascading the count-rate independent SRE and the count-rate dependent PPE.

  19. A LYMAN BREAK GALAXY IN THE EPOCH OF REIONIZATION FROM HUBBLE SPACE TELESCOPE GRISM SPECTROSCOPY

    SciTech Connect (OSTI)

    Rhoads, James E.; Malhotra, Sangeeta; Cohen, Seth; Zheng Zhenya; Stern, Daniel; Dickinson, Mark; Pirzkal, Norbert; Grogin, Norman; Koekemoer, Anton; Peth, Michael A.; Spinrad, Hyron; Reddy, Naveen; Hathi, Nimish; Budavari, Tamas; Ferreras, Ignacio; Gardner, Jonathan P.; Gronwall, Caryl; Haiman, Zoltan; Kuemmel, Martin; Meurer, Gerhardt; and others

    2013-08-10

    We present observations of a luminous galaxy at z = 6.573-the end of the reionization epoch-which has been spectroscopically confirmed twice. The first spectroscopic confirmation comes from slitless Hubble Space Telescope Advanced Camera for Surveys grism spectra from the PEARS survey (Probing Evolution And Reionization Spectroscopically), which show a dramatic continuum break in the spectrum at rest frame 1216 A. The second confirmation is done with Keck + DEIMOS. The continuum is not clearly detected with ground-based spectra, but high wavelength resolution enables the Ly{alpha} emission line profile to be determined. We compare the line profile to composite line profiles at z = 4.5. The Ly{alpha} line profile shows no signature of a damping wing attenuation, confirming that the intergalactic gas is ionized at z = 6.57. Spectra of Lyman breaks at yet higher redshifts will be possible using comparably deep observations with IR-sensitive grisms, even at redshifts where Ly{alpha} is too attenuated by the neutral intergalactic medium to be detectable using traditional spectroscopy from the ground.

  20. Heating the intergalactic medium by X-rays from population III binaries in high-redshift galaxies

    SciTech Connect (OSTI)

    Xu, Hao; Norman, Michael L.; Ahn, Kyungjin; Wise, John H.; O'Shea, Brian W. E-mail: mlnorman@ucsd.edu E-mail: jwise@gatech.edu

    2014-08-20

    Due to their long mean free path, X-rays are expected to have an important impact on cosmic reionization by heating and ionizing the intergalactic medium (IGM) on large scales, especially after simulations have suggested that Population III (Pop III) stars may form in pairs at redshifts as high as 20-30. We use the Pop III distribution and evolution from a self-consistent cosmological radiation hydrodynamic simulation of the formation of the first galaxies and a simple Pop III X-ray binary model to estimate their X-ray output in a high-density region larger than 100 comoving (Mpc){sup 3}. We then combine three different methodsray tracing, a one-zone model, and X-ray background modelingto investigate the X-ray propagation, intensity distribution, and long-term effects on the IGM thermal and ionization state. The efficiency and morphology of photoheating and photoionization are dependent on the photon energies. The sub-kiloelectronvolt X-rays only impact the IGM near the sources, while the kiloelectronvolt photons contribute significantly to the X-ray background and heat and ionize the IGM smoothly. The X-rays just below 1 keV are most efficient in heating and ionizing the IGM. We find that the IGM might be heated to over 100 K by z = 10 and the high-density source region might reach 10{sup 4} K, limited by atomic hydrogen cooling. This may be important for predicting the 21 cm neutral hydrogen signals. On the other hand, the free electrons from X-ray ionizations are not enough to contribute significantly to the optical depth of the cosmic microwave background to the Thomson scattering.

  1. safety of space

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

    of space - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel Cycle Defense Waste Management Programs Advanced Nuclear Energy

  2. AERaSPACE CORPORATION

    Office of Legacy Management (LM)

    THE ' AERaSPACE CORPORATION Suite 300, 955 L' &njon~ Pkzza. S. W., Washingvan. D.C. 200242174, Tekphanc (202) 488~6CllO 7117-03.87.cdy.43 23 September 1987 CA CA.Ot M r. Andrew Wallo, III. NE-23 Division of Facility & Site cr.05 Decommissioning Projects FL .0-d U.S. Department of Energy TAl.OL Germantown; Maryland 20545 JA/.OZ 1hJ . o-01 Dear M r. Wallo: flA.05 ELIMINATION RECOMMENDATION -- COLLEGES AND UNIVERSITIES M /4.0-* 11 D.OF The attached elimination recommendation was prepared in

  3. Strain Accommodation By Facile WO6 Octahedral Distortion and Tilting During WO3 Heteroepitaxy on SrTiO3(001)

    SciTech Connect (OSTI)

    Du, Yingge; Gu, Meng; Varga, Tamas; Wang, Chong M.; Bowden, Mark E.; Chambers, Scott A.

    2014-08-27

    In this paper, we show that compared to other BO6 octahedra in ABO3 structured perovskite oxides, the WO6 octahedra in tungsten trioxide (WO3) can withstand a much larger degree of distortion and tilting to accommodate interfacial strain, which in turn strongly impact the nucleation, structure, and defect formation during the epitaxial growth of WO3 on SrTiO3(001). A meta-stable tetragonal phase can be stabilized by epitaxy and a thickness dependent phase transition (tetragonal to monoclinic) is observed. In contrast to misfit dislocations to accommodate the interfacial stain, the facial WO6 octahedral distortion and tilting give rise to three types of planar defects that affect more than 15 monolayers from the interface. These atomically resolved, unusual interfacial defects may significantly alter the electronic, electrochromic, and mechanical properties of the epitaxial films.

  4. No Prejudice in Space

    SciTech Connect (OSTI)

    Cotta, R.C.; Gainer, J.S.; Hewett, J.L.; Rizzo, T.G.; /SLAC

    2010-08-26

    We present a summary of recent results obtained from a scan of the 19-dimensional parameter space of the pMSSM and its implications for dark matter searches. We have generated a large set of points in parameter space (which we call 'models') for the 19-parameter CP-conserving pMSSM, where MFV has been assumed. We subjected these models to numerous experimental and theoretical constraints to obtain a set of {approx}68 K models which are consistent with existing data. We attempted to be somewhat conservative in our implementation of these constraints; in particular we only demanded that the relic density of the LSP not be greater than the measured value of {Omega}H{sup 2} for non-baryonic dark matter, rather than assuming that the LSP must account for the entire observed relic density. Examining the properties of the neutralinos in these models, we find that many are relatively pure gauge eigenstates with Higgsinos being the most common, followed by Winos. The relative prevalence of Higgsino and Wino LSPs leads many of our models to have a chargino as nLSP, often with a relatively small mass splitting between this nLSP and the LSP; this has important consequences in both collider and astroparticle phenomenology. We find that, in general, the LSP in our models provides a relatively small ({approx} 4%) contribution to the dark matter, however there is a long tail to this distribution and a substantial number of models for which the LSP makes up all or most of the dark matter. Typically these neutralinos are mostly Binos. Examining the signatures of our models in direct and indirect dark matter detection experiments, we find a wide range of signatures for both cases. In particular, we find a much larger range of WIMP-nucleon cross sections than is found in any particular model of SUSY-breaking. As these cross sections also enter the regions of parameter space suggested by non-SUSY models, it appears that the discovery of WIMPs in direct detection experiments might not be sufficient to determine the correct model of the underlying physics. As a first look at the signatures of these models in indirect detection experiments, we examined whether our models could explain the PAMELA excess in the positron to electron ratio at high energies. We find that there are models which fit the PAMELA data rather well, and some of these have significantly smaller boost factors than generally assumed for a thermal relic. The study of the pMSSM presents exciting new possibilities for SUSY phenomenology. The next few years will hopefully see important discoveries both in colliders and in satellite or ground-based astrophysical experiments. It is important that we follow the data and not our existing prejudices; hopefully this sort of relatively model-independent approach to collider and astrophysical phenomenology can be useful in this regard.

  5. Phase space quantum mechanics - Direct

    SciTech Connect (OSTI)

    Nasiri, S.; Sobouti, Y.; Taati, F.

    2006-09-15

    Conventional approach to quantum mechanics in phase space (q,p), is to take the operator based quantum mechanics of Schroedinger, or an equivalent, and assign a c-number function in phase space to it. We propose to begin with a higher level of abstraction, in which the independence and the symmetric role of q and p is maintained throughout, and at once arrive at phase space state functions. Upon reduction to the q- or p-space the proposed formalism gives the conventional quantum mechanics, however, with a definite rule for ordering of factors of noncommuting observables. Further conceptual and practical merits of the formalism are demonstrated throughout the text.

  6. Radioisotopes: Energy for Space Exploration

    SciTech Connect (OSTI)

    Carpenter, Bob; Green, James; Bechtel, Ryan

    2011-01-01

    Through a strong partnership between the Energy Department's office of Nuclear Energy and NASA, Radioisotope Power Systems have been providing the energy for deep space exploration.

  7. Radioisotopes: Energy for Space Exploration

    ScienceCinema (OSTI)

    Carpenter, Bob; Green, James; Bechtel, Ryan

    2013-05-29

    Through a strong partnership between the Energy Department's office of Nuclear Energy and NASA, Radioisotope Power Systems have been providing the energy for deep space exploration.

  8. Space-Based Solar Power

    Broader source: Energy.gov [DOE]

    Capturing solar power in space for use as energy on Earth seems farfetched. But recent developments could make this a reality in coming years.

  9. TANK SPACE ALTERNATIVES ANALYSIS REPORT

    SciTech Connect (OSTI)

    TURNER DA; KIRCH NW; WASHENFELDER DJ; SCHAUS PS; WODRICH DD; WIEGMAN SA

    2010-04-27

    This report addresses the projected shortfall of double-shell tank (DST) space starting in 2018. Using a multi-variant methodology, a total of eight new-term options and 17 long-term options for recovering DST space were evaluated. These include 11 options that were previously evaluated in RPP-7702, Tank Space Options Report (Rev. 1). Based on the results of this evaluation, two near-term and three long-term options have been identified as being sufficient to overcome the shortfall of DST space projected to occur between 2018 and 2025.

  10. Building America Webinar: Retrofitting Central Space Conditioning...

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

    Control strategies to improve hydronic space heating performance Building America Webinar: Retrofitting Central Space Conditioning Strategies for Multifamily Buildings - Control ...

  11. Building America Webinar: Retrofitting Central Space Conditioning...

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

    Building America Webinar: Retrofitting Central Space Conditioning Strategies for ... Webinar: Retrofitting Central Space Conditioning Strategies for Multifamily Buildings

  12. Is the misalignment of the Local Group velocity and the dipole generated by the 2MASS Redshift Survey typical in {lambda} cold dark matter and the halo model of galaxies?

    SciTech Connect (OSTI)

    Erdogdu, Pirin; Lahav, Ofer

    2009-08-15

    We predict the acceleration of the Local Group generated by the 2MASS Redshift Survey within the framework of {lambda} cold dark matter and the halo model of galaxies. We show that as the galaxy fluctuations derived from the halo model have more power on small scales compared with the mass fluctuations, the misalignment angle between the CMB velocity vector and the 2MASS Redshift Survey dipole is in reasonable agreement with the observed 21 deg. This statistical analysis suggests that it is not necessary to invoke a hypothetical nearby galaxy or a distant cluster to explain this misalignment.

  13. Cosmology without cosmic variance

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

    Bernstein, Gary M.; Cai, Yan -Chuan

    2011-10-01

    The growth of structures in the Universe is described by a function G that is predicted by the combination of the expansion history of the Universe and the laws of gravity within it. We examine the improvements in constraints on G that are available from the combination of a large-scale galaxy redshift survey with a weak gravitational lensing survey of background sources. We describe a new combination of such observations that in principle this yields a measure of the growth rate that is free of sample variance, i.e. the uncertainty in G can be reduced without bound by increasing themore » number of redshifts obtained within a finite survey volume. The addition of background weak lensing data to a redshift survey increases information on G by an amount equivalent to a 10-fold increase in the volume of a standard redshift-space distortion measurement - if the lensing signal can be measured to sub-per cent accuracy. This argues that a combined lensing and redshift survey over a common low-redshift volume of the Universe is a more powerful test of general relativity than an isolated redshift survey over larger volume at high redshift, especially as surveys begin to cover most of the available sky.« less

  14. THE PHYSICS OF THE FAR-INFRARED-RADIO CORRELATION. II. SYNCHROTRON EMISSION AS A STAR FORMATION TRACER IN HIGH-REDSHIFT GALAXIES

    SciTech Connect (OSTI)

    Lacki, Brian C.; Thompson, Todd A.

    2010-07-01

    We construct one-zone steady-state models of cosmic ray (CR) injection, cooling, and escape over the entire dynamic range of the FIR-radio correlation (FRC), from normal galaxies to starbursts, over the redshift interval 0 {<=} z {<=} 10. Normal galaxies with low star formation rates become radio faint at high z, because inverse Compton (IC) losses off the cosmic microwave background (CMB) cool CR electrons and positrons rapidly, suppressing their nonthermal radio emission. However, we find that this effect occurs at higher redshifts than previously expected, because escape, bremsstrahlung, ionization, and starlight IC losses act to counter this effect and preserve the radio luminosity of galaxies. The radio dimming of star-forming galaxies at high z is not just a simple competition between magnetic field energy density and the CMB energy density; the CMB must also compete with every other loss process. We predict relations for the critical redshift when radio emission is significantly suppressed compared to the z {approx} 0 FRC as a function of star formation rate per unit area. For example, a MilkyWay like spiral becomes radio faint at z {approx} 2, while an M82-like starburst does not become radio faint until z {approx} 10-20. We show that the 'buffering' effect of non-synchrotron losses improves the detectability of star-forming galaxies in synchrotron radio emission with Expanded Very Large Array and Square Kilometer Array. Additionally, we provide a quantitative explanation for the relative radio brightness of some high-z submillimeter galaxies. We show that at fixed star formation rate surface density, galaxies with larger CR scale heights are radio bright with respect to the FRC, because of weaker bremsstrahlung and ionization losses compared to compact starbursts. We predict that these 'puffy starbursts' should have steeper radio spectra than compact galaxies with the same star formation rate surface density. We find that radio-bright submillimeter galaxies alone cannot explain the excess radio emission reported by ARCADE2, but they may significantly enhance the diffuse radio background with respect to a naive application of the z {approx} 0 FRC.

  15. SMA observations on faint submillimeter galaxies with S {sub 850} < 2 mJy: Ultra dusty low-luminosity galaxies at high redshift

    SciTech Connect (OSTI)

    Chen, Chian-Chou; Cowie, Lennox L.; Barger, Amy J.; Williams, Jonathan P.; Wang, Wei-Hao

    2014-07-01

    We obtained Submillimeter Array (SMA) observations of eight faint (intrinsic 850 ?m fluxes < 2 mJy) submillimeter galaxies (SMGs) discovered in SCUBA images of the massive lensing cluster fields A370, A2390, and A1689 and detected five. In total, we obtain five SMA detections, all of which have de-lensed fluxes <1 mJy with estimated total infrared luminosities 10{sup 10}-10{sup 12} L {sub ?}, comparable to luminous infrared galaxies and normal star-forming galaxies. Based on the latest number counts, these galaxies contribute ?70% of the 850 ?m extragalactic background light and represent the dominant star-forming galaxy population in the dusty universe. However, only 40{sub ?16}{sup +30}% of our faint SMGs would be detected in deep optical or near-infrared surveys, which suggests many of these sources are at high redshifts (z ? 3) or extremely dusty, and they are not included in current star formation history estimates.

  16. COMPLETE IONIZATION OF THE NEUTRAL GAS: WHY THERE ARE SO FEW DETECTIONS OF 21 cm HYDROGEN IN HIGH-REDSHIFT RADIO GALAXIES AND QUASARS

    SciTech Connect (OSTI)

    Curran, S. J.; Whiting, M. T.

    2012-11-10

    From the first published z {approx}> 3 survey of 21 cm absorption within the hosts of radio galaxies and quasars, Curran et al. found an apparent dearth of cool neutral gas at high redshift. From a detailed analysis of the photometry, each object is found to have a {lambda} = 1216 A continuum luminosity in excess of L {sub 1216} {approx} 10{sup 23} W Hz{sup -1}, a critical value above which 21 cm has never been detected at any redshift. At these wavelengths, and below, hydrogen is excited above the ground state so that it cannot absorb in 21 cm. In order to apply the equation of photoionization equilibrium, we demonstrate that this critical value also applies to the ionizing ({lambda} {<=} 912 A) radiation. We use this to show, for a variety of gas density distributions, that upon placing a quasar within a galaxy of gas, there is always an ultraviolet luminosity above which all of the large-scale atomic gas is ionized. While in this state, the hydrogen cannot be detected or engage in star formation. Applying the mean ionizing photon rate of all of the sources searched, we find, using canonical values for the gas density and recombination rate coefficient, that the observed critical luminosity gives a scale length (3 kpc) similar that of the neutral hydrogen (H I) in the Milky Way, a large spiral galaxy. Thus, this simple yet physically motivated model can explain the critical luminosity (L {sub 912} {approx} L {sub 1216} {approx} 10{sup 23} W Hz{sup -1}), above which neutral gas is not detected. This indicates that the non-detection of 21 cm absorption is not due to the sensitivity limits of current radio telescopes, but rather that the lines of sight to the quasars, and probably the bulk of the host galaxies, are devoid of neutral gas.

  17. RECENT STELLAR MASS ASSEMBLY OF LOW-MASS STAR-FORMING GALAXIES AT REDSHIFTS 0.3 < z < 0.9

    SciTech Connect (OSTI)

    Rodrguez-Muoz, Luca; Gallego, Jess; De Paz, Armando Gil; Villar, Vctor; Tresse, Laurence; Charlot, Stphane; Barro, Guillermo

    2015-01-20

    The epoch when low-mass star-forming galaxies (LMSFGs) form the bulk of their stellar mass is uncertain. While some models predict an early formation, others favor a delayed scenario until later ages of the universe. We present constraints on the star formation histories (SFHs) of a sample of LMSFGs obtained through the analysis of their spectral energy distributions using a novel approach that (1) consistently combines photometric (broadband) and spectroscopic (equivalent widths of emission lines) data, and (2) uses physically motivated SFHs with non-uniform variations of the star formation rate (SFR) as a function of time. The sample includes 31 spectroscopically confirmed LMSFGs (7.3 ? log M {sub *}/M {sub ?} ? 8.0), at 0.3 < z {sub spec} < 0.9, in the Extended-Chandra Deep Field-South field. Among them, 24 were selected with photometric stellar mass log M {sub *}/M {sub ?} < 8.0, 0.3 < z {sub phot} < 1.0, and m {sub NB816,} {sub AB} < 26 mag; the remaining 7 were selected as blue compact dwarfs within the same photometric redshift and magnitude ranges. We also study a secondary sample of 43 more massive spectroscopically confirmed galaxies (8.0 < log M {sub *}/M {sub ?} ? 9.1), selected with the same criteria. The SFRs and stellar masses derived for both samples place our targets on the standard main sequence of star-forming galaxies. The median SFH of LMSFGs at intermediate redshifts appears to form 90% of the median stellar mass inferred for the sample in the ?0.5-1.8Gyr immediately preceding the observation. These results suggest a recent stellar mass assembly for LMSFGs, consistent with the cosmological downsizing trends. We find similar median SFH timescales for the more massive secondary sample.

  18. Octahedral distortion induced magnetic anomalies in LaMn{sub 0.5}Co{sub 0.5}O{sub 3} single crystals

    SciTech Connect (OSTI)

    Manna, Kaustuv Elizabeth, Suja; Anil Kumar, P. S.; Bhadram, Venkata Srinu; Narayana, Chandrabhas

    2014-07-28

    Single crystals of LaMn{sub 0.5}Co{sub 0.5}O{sub 3} belonging to the ferromagnetic-insulator and distorted perovskite class were grown using a four-mirror optical float zone furnace. The as-grown crystal crystallizes into an orthorhombic Pbnm structure. The spatially resolved 2D Raman scan reveals a strain-induced distribution of transition metal (TM)oxygen (O) octahedral deformation in the as-grown crystal. A rigorous annealing process releases the strain, thereby generating homogeneous octahedral distortion. The octahedra tilt by reducing the bond angle TM-O-TM, resulting in a decline of the exchange energy in the annealed crystal. The critical behavior is investigated from the bulk magnetization. It is found that the ground state magnetic behavior assigned to the strain-free LaMn{sub 0.5}Co{sub 0.5}O{sub 3} crystal is of the 3D Heisenberg kind. Strain induces mean field-like interaction in some sites, and consequently, the critical exponents deviate from the 3D Heisenberg class in the as-grown crystal. The temperature-dependent Raman scattering study reveals strong spin-phonon coupling and the existence of two magnetic ground states in the same crystal.

  19. Space Instrument Realization (ISR-5)

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

    5 Space Instrument Realization Providing expertise to support the design and fabrication of space-based custom instrumentation Contacts Group Leader Amy Regan Email Staff Operations Manager Tanner Trujillo Email Administrative Specialist Hannah Cross Email Scientist sees his reflection as he works on the Cibola satellite. Scientist sees his reflection as he works on the Cibola satellite. Scientist sees his reflection as he works on the Cibola satellite, which was designed to prove that

  20. Nuclear Propulsion in Space (1968)

    ScienceCinema (OSTI)

    None

    2014-06-17

    Project NERVA was an acronym for Nuclear Engine for Rocket Vehicle Application, a joint program of the U.S. Atomic Energy Commission and NASA managed by the Space Nuclear Propulsion Office (SNPO) at the Nuclear Rocket Development Station in Jackass Flats, Nevada U.S.A. Between 1959 and 1972, the Space Nuclear Propulsion Office oversaw 23 reactor tests, both the program and the office ended at the end of 1972.

  1. Nuclear Propulsion in Space (1968)

    SciTech Connect (OSTI)

    2012-06-23

    Project NERVA was an acronym for Nuclear Engine for Rocket Vehicle Application, a joint program of the U.S. Atomic Energy Commission and NASA managed by the Space Nuclear Propulsion Office (SNPO) at the Nuclear Rocket Development Station in Jackass Flats, Nevada U.S.A. Between 1959 and 1972, the Space Nuclear Propulsion Office oversaw 23 reactor tests, both the program and the office ended at the end of 1972.

  2. Building America Webinar: Retrofitting Central Space Conditioning

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

    Strategies for Multifamily Buildings - Control strategies to improve hydronic space heating performance | Department of Energy Control strategies to improve hydronic space heating performance Building America Webinar: Retrofitting Central Space Conditioning Strategies for Multifamily Buildings - Control strategies to improve hydronic space heating performance This presentation is included in the July 16, 2014, webinar and discusses various control strategies to improve hydronic space heating

  3. Observed galaxy number counts on the lightcone up to second order: I. Main result

    SciTech Connect (OSTI)

    Bertacca, Daniele; Maartens, Roy; Clarkson, Chris E-mail: roy.maartens@gmail.com

    2014-09-01

    We present the galaxy number overdensity up to second order in redshift space on cosmological scales for a concordance model. The result contains all general relativistic effects up to second order that arise from observing on the past light cone, including all redshift effects, lensing distortions from convergence and shear, and contributions from velocities, Sachs-Wolfe, integrated SW and time-delay terms. This result will be important for accurate calculation of the bias on estimates of non-Gaussianity and on precision parameter estimates, introduced by nonlinear projection effects.

  4. Evaluation of Artifacts and Distortions of Titanium Applicators on 3.0-Tesla MRI: Feasibility of Titanium Applicators in MRI-Guided Brachytherapy for Gynecological Cancer

    SciTech Connect (OSTI)

    Kim, Yusung, E-mail: yusung-kim@uiowa.edu [Department of Radiation Oncology, University of Iowa, Iowa City, IA (United States); Muruganandham, Manickam; Modrick, Joseph M.; Bayouth, John E. [Department of Radiation Oncology, University of Iowa, Iowa City, IA (United States)

    2011-07-01

    Purpose: The aim of this study was to characterize the levels of artifacts and distortions of titanium applicators on 3.0-Tesla magnetic resonance imaging (MRI). Methods and Materials: Fletcher-Suit-Delclos-style tandem and ovoids (T and O) and tandem and ring applicator (T and R) were examined. The quality assurance (QA) phantoms for each applicator were designed and filled with copper sulphate solution (1.5 g/l). The artifacts were quantified with the registration of corresponding computed tomography (CT) images. A favorable MR sequence was searched in terms of artifacts. Using the sequence, the artifacts were determined. The geometric distortions induced by the applicators were quantified through each registration of CT and MRI without applicators. The artifacts of T and O were also evaluated on in vivo MRI datasets of 5 patients. Results: T1-weighted MRI with 1-mm slice thickness was found as a favorable MR sequence. Applying the sequence, the artifacts at the tandem tip of T and O and T and R were determined as 1.5 {+-} 0.5 mm in a superior direction in phantom studies. In the ovoids of T and O, we found artifacts less than 1.5 {+-} 0.5 mm. The artifacts of a T and O tandem in vivo were found as less than 2.6 {+-} 1.3 mm on T1-weighted MRI, whereas less than 6.9 {+-} 3.4 mm on T2-weighted MRI. No more than 1.2 {+-} 0.6 mm (3.0 {+-} 1.5 mm) of distortions, due to a titanium applicator, were measured on T1-weighted MRI (T2-). Conclusion: In 3.0-Tesla MRI, we found the artifact widths at the tip of tandem were less than 1.5 {+-} 0.5 mm for both T and O and T and R when using T1-weighted MRI in phantom studies. However, exclusive 3.0-Tesla MRI-guided brachytherapy planning with a titanium applicator should be cautiously implemented.

  5. Solar Space Heat | Open Energy Information

    Open Energy Info (EERE)

    Solar Space Heat Jump to: navigation, search TODO: Add description List of Solar Space Heat Incentives Retrieved from "http:en.openei.orgwindex.php?titleSolarSpaceHeat&oldid...

  6. Integration of space weather into space situational awareness

    SciTech Connect (OSTI)

    Reeves, Geoffrey D

    2010-11-09

    Rapid assessment of space weather effects on satellites is a critical step in anomaly resolution and satellite threat assessment. That step, however, is often hindered by a number of factors including timely collection and delivery of space weather data and the inherent com plexity of space weather information. As part of a larger, integrated space situational awareness program, Los Alamos National Laboratory has developed prototype operational space weather tools that run in real time and present operators with customized, user-specific information. The Dynamic Radiation Environment Assimilation Model (DREAM) focuses on the penetrating radiation environment from natural or nuclear-produced radiation belts. The penetrating radiation environment is highly dynamic and highly orbit-dependent. Operators often must rely only on line plots of 2 MeV electron flux from the NOAA geosynchronous GOES satellites which is then assumed to be representative of the environment at the satellite of interest. DREAM uses data assimilation to produce a global, real-time, energy dependent specification. User tools are built around a distributed service oriented architecture (SOA) which will allow operators to select any satellite from the space catalog and examine the environment for that specific satellite and time of interest. Depending on the application operators may need to examine instantaneous dose rates and/or dose accumulated over various lengths of time. Further, different energy thresholds can be selected depending on the shielding on the satellite or instrument of interest. In order to rapidly assess the probability that space weather was the cause of anomalous operations, the current conditions can be compared against the historical distribution of radiation levels for that orbit. In the simplest operation a user would select a satellite and time of interest and immediately see if the environmental conditions were typical, elevated, or extreme based on how often those conditions occur in that orbit. This allows users to rapidly rule in or out environmental causes of anomalies. The same user interface can also allow users to drill down for more detailed quantitative information. DREAM can be run either from a distributed web-based user interface or as a stand-alone application for secure operations. In this paper we discuss the underlying structure of the DREAM model and demonstrate the user interface that we have developed . We also present some prototype data products and user interfaces for DREAM and discuss how space environment information can be seamlessly integrated into operational SSA systems.

  7. Space Conditioning Standing Technical Commitee Presentation ...

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

    Commitee Presentation Space Conditioning Standing Technical Commitee Presentation This presentation outlines the goals of the Space Conditioning Standing Technical ommittee, as...

  8. Space-Time Insight | Open Energy Information

    Open Energy Info (EERE)

    Space-Time Insight Jump to: navigation, search Name: Space-Time Insight Address: 45680 Northport Loop East Place: Fremont, California Zip: 94538 Region: Bay Area Sector: Efficiency...

  9. Passive Solar Space Heat | Open Energy Information

    Open Energy Info (EERE)

    Passive Solar Space Heat Jump to: navigation, search TODO: Add description List of Passive Solar Space Heat Incentives Retrieved from "http:en.openei.orgwindex.php?titlePassiv...

  10. Building America Webinar: High Performance Space Conditioning...

    Energy Savers [EERE]

    Webinar: High Performance Space Conditioning Systems, Part I: Heating and Cooling with Mini-Splits in the Northeast Building America Webinar: High Performance Space Conditioning...

  11. Total Space Heating Water Heating Cook-

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    Commercial Buildings Energy Consumption Survey: Energy End-Use Consumption Tables Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing...

  12. Lakeview Residences Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Lakeview Residences Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Lakeview Residences Space Heating Low Temperature Geothermal Facility...

  13. Thinking"" telescopes for autonomous space situational awareness...

    Office of Scientific and Technical Information (OSTI)

    Conference: Thinking"" telescopes for autonomous space situational awareness Citation Details In-Document Search Title: Thinking"" telescopes for autonomous space situational...

  14. Building America Webinar: High Performance Space Conditioning...

    Energy Savers [EERE]

    Webinar: High Performance Space Conditioning Systems, Part II - Compact Buried Ducts Building America Webinar: High Performance Space Conditioning Systems, Part II - Compact Buried...

  15. Dutch Space BV | Open Energy Information

    Open Energy Info (EERE)

    Dutch Space BV Jump to: navigation, search Name: Dutch Space BV Place: Leiden, Netherlands Zip: 2333 Sector: Solar Product: Leiden-based supplier of subsystems for the European...

  16. European Space Agency | Open Energy Information

    Open Energy Info (EERE)

    Space Agency Jump to: navigation, search Name: European Space Agency Place: Paris, France Zip: 75738 Sector: Services, Solar Product: String representation "ESAs job is ......

  17. Solar space heating | Open Energy Information

    Open Energy Info (EERE)

    Solar space heating Jump to: navigation, search (The following text is derived from the United States Department of Energy's description of solar space heating technology.)1...

  18. Building America Webinar: High Performance Space Conditioning...

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

    II - Design Options for Locating Ducts within Conditioned Space Building America Webinar: High Performance Space Conditioning Systems, Part II - Design Options for Locating Ducts...

  19. Total Space Heating Water Heating Cook-

    Gasoline and Diesel Fuel Update (EIA)

    Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 1,870 1,276...

  20. Total Space Heating Water Heating Cook-

    Gasoline and Diesel Fuel Update (EIA)

    Energy Consumption Survey: Energy End-Use Consumption Tables Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All...

  1. Total Space Heating Water Heating Cook-

    Gasoline and Diesel Fuel Update (EIA)

    Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 1,602 1,397...

  2. Total Space Heating Water Heating Cook-

    Gasoline and Diesel Fuel Update (EIA)

    Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings ... 2,037...

  3. Sustainable Spaces Inc | Open Energy Information

    Open Energy Info (EERE)

    Spaces Inc Jump to: navigation, search Name: Sustainable Spaces Inc. Place: San Francisco, California Zip: 94103 Sector: Carbon Product: California-based provider of energy audits...

  4. Building America Expert Meeting: Simplified Space Conditioning...

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

    Simplified Space Conditioning Strategies for Energy Efficient Houses Building America Expert Meeting: Simplified Space Conditioning Strategies for Energy Efficient Houses The ...

  5. Field calculations, single-particle tracking, and beam dynamics with space charge in the electron lens for the Fermilab Integrable Optics Test Accelerator

    SciTech Connect (OSTI)

    Noll, Daniel; Stancari, Giulio

    2015-11-17

    An electron lens is planned for the Fermilab Integrable Optics Test Accelerator as a nonlinear element for integrable dynamics, as an electron cooler, and as an electron trap to study space-charge compensation in rings. We present the main design principles and constraints for nonlinear integrable optics. A magnetic configuration of the solenoids and of the toroidal section is laid out. Singleparticle tracking is used to optimize the electron path. Electron beam dynamics at high intensity is calculated with a particle-in-cell code to estimate current limits, profile distortions, and the effects on the circulating beam. In the conclusions, we summarize the main findings and list directions for further work.

  6. Space

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

    New gamma-ray observatory begins operations at Sierra Negra volcano in the state of Puebla, Mexico The High-Altitude Water Cherenkov Gamma Ray Observatory has begun formal...

  7. Space Power Systems Documents | Department of Energy

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

    Space Power Systems Documents Space Power Systems Documents August 5, 2015 Memorandum of Understanding between DOE and NASA concerning RPS for space missions The purpose of this agreement is to delineate the authorities and responsibilities of the Department of Energy (DOE) and the National Aeronautics and Space Administration (NASA) (the parties) in the research, technology development, design, production, delivery, space vehicle integration, and launch phases with respect to certain

  8. Simplified Space Conditioning | Department of Energy

    Energy Savers [EERE]

    Simplified Space Conditioning Simplified Space Conditioning This presentation was delivered at the U.S. Department of Energy Building America Technical Update meeting on April 29-30, 2013, in Denver, Colorado. PDF icon cq4_simplified_space_cond_prahl.pdf More Documents & Publications Building America Webinar: High Performance Space Conditioning Systems, Part I: Simplified Space Conditioning in Low Load Homes Critical Question #4: What are the Best Off-the-Shelf HVAC Solutions for Low-Load,

  9. Flat space physics from holography

    SciTech Connect (OSTI)

    Bousso, Raphael

    2004-02-06

    We point out that aspects of quantum mechanics can be derived from the holographic principle, using only a perturbative limit of classical general relativity. In flat space, the covariant entropy bound reduces to the Bekenstein bound. The latter does not contain Newton's constant and cannot operate via gravitational backreaction. Instead, it is protected by--and in this sense, predicts--the Heisenberg uncertainty principle.

  10. space exploration radioisotope power systems

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

    space exploration radioisotope power systems - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel Cycle Defense Waste

  11. Large aperture diffractive space telescope

    DOE Patents [OSTI]

    Hyde, Roderick A. (Livermore, CA)

    2001-01-01

    A large (10's of meters) aperture space telescope including two separate spacecraft--an optical primary objective lens functioning as a magnifying glass and an optical secondary functioning as an eyepiece. The spacecraft are spaced up to several kilometers apart with the eyepiece directly behind the magnifying glass "aiming" at an intended target with their relative orientation determining the optical axis of the telescope and hence the targets being observed. The objective lens includes a very large-aperture, very-thin-membrane, diffractive lens, e.g., a Fresnel lens, which intercepts incoming light over its full aperture and focuses it towards the eyepiece. The eyepiece has a much smaller, meter-scale aperture and is designed to move along the focal surface of the objective lens, gathering up the incoming light and converting it to high quality images. The positions of the two space craft are controlled both to maintain a good optical focus and to point at desired targets which may be either earth bound or celestial.

  12. Space-Based Solar Power | Department of Energy

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

    Space-Based Solar Power Space-Based Solar Power Graphics by Sarah Gerrity. Interactivity by

  13. HUBBLE SPACE TELESCOPE EMISSION-LINE GALAXIES AT z ∼ 2: THE MYSTERY OF NEON

    SciTech Connect (OSTI)

    Zeimann, Gregory R.; Ciardullo, Robin; Gebhardt, Henry; Gronwall, Caryl; Hagen, Alex; Trump, Jonathan R.; Bridge, Joanna S.; Luo, Bin; Schneider, Donald P.

    2015-01-01

    We use near-infrared grism spectroscopy from the Hubble Space Telescope to examine the strength of [Ne III] λ3869 relative to Hβ, [O II] λ3727, and [O III] λ5007 in 236 low-mass (7.5 ≲ log (M {sub *}/M {sub ☉}) ≲ 10.5) star-forming galaxies in the redshift range 1.90 < z < 2.35. By stacking the data by stellar mass, we show that the [Ne III]/[O II] ratios of the z ∼ 2 universe are marginally higher than those seen in a comparable set of local Sloan Digital Sky Survey galaxies, and that [Ne III]/[O III] is enhanced by ∼0.2 dex. We consider the possible explanations for this ∼4σ result, including higher oxygen depletion out of the gas phase, denser H II regions, higher production of {sup 22}Ne via Wolf-Rayet stars, and the existence of a larger population of X-ray obscured active galactic nuclei at z ∼ 2 compared to z ∼ 0. None of these simple scenarios, alone, are favored to explain the observed line ratios. We conclude by suggesting several avenues of future observations to further explore the mystery of enhanced [Ne III] emission.

  14. Los Alamos Space Weather Summer School

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

    for Non-U.S Citizens Mentors, Projects Lectures Papers, Reports Photos NSEC IGPPS Space Weather Summer School Los Alamos Space Weather Summer School June 6 - July 29, 2016...

  15. Total Space Heating Water Heating Cook-

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    Tables Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 634 578 46 1 Q 116.4 106.3...

  16. WPN 08-4: Space Heater Policy

    Broader source: Energy.gov [DOE]

    To update the policy relation to space heaters for the low-income Weatherization Assistance Program. This policy supersedes the previous space heater policy issued by memoranda on March 18, 1992.

  17. Invariant distributions on compact homogeneous spaces

    SciTech Connect (OSTI)

    Gorbatsevich, V V

    2013-12-31

    In this paper, we study distributions on compact homogeneous spaces, including invariant distributions and also distributions admitting asub-Riemannian structure. We first consider distributions of dimension 1 and 2 on compact homogeneous spaces. After this, we study the cases of compact homogeneous spaces of dimension 2, 3, and 4 in detail. Invariant distributions on simply connected compact homogeneous spaces are also treated. Bibliography: 18 titles.

  18. Ames Lab 101: Growing Crystals in Space

    SciTech Connect (OSTI)

    Trivedi, Rohit

    2011-01-01

    Rohit Trivedi, distinguished professor of materials science and engineering, discusses his research with NASA to grow crystals in space.

  19. National Aeronautic and Space Administration | National Nuclear...

    National Nuclear Security Administration (NNSA)

    Aeronautic and Space Administration | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation...

  20. Ames Lab 101: Growing Crystals in Space

    ScienceCinema (OSTI)

    Trivedi, Rohit

    2012-08-29

    Rohit Trivedi, distinguished professor of materials science and engineering, discusses his research with NASA to grow crystals in space.

  1. DREAM tool increases space weather predictions

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

    DREAM tool increases space weather predictions DREAM tool increases space weather predictions Model addresses radiation hazards of the space environment on space systems. April 13, 2012 Scientists studying Earth's radiation belts have a new modeling tool called Dynamic Radiation Environment Assimilation Model (DREAM). Scientists studying Earth's radiation belts have a new modeling tool called Dynamic Radiation Environment Assimilation Model (DREAM). DREAM is a modeling tool that improves the

  2. Building America Webinar: Retrofitting Central Space Conditioning...

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

    Building America Webinar: Retrofitting Central Space Conditioning Strategies for ... Building America Webinar: High Performance Enclosure Strategies: Part II, New Construction ...

  3. Atomic Power in Space: A History

    DOE R&D Accomplishments [OSTI]

    1987-03-01

    "Atomic Power in Space," a history of the Space Isotope Power Program of the United States, covers the period from the program's inception in the mid-1950s through 1982. Written in non-technical language, the history is addressed to both the general public and those more specialized in nuclear and space technologies. Interplanetary space exploration successes and achievements have been made possible by this technology, for which there is no known substitue.

  4. Atomic power in space: A history

    SciTech Connect (OSTI)

    Not Available

    1987-03-01

    ''Atomic Power in Space,'' a history of the Space Isotope Power Program of the United States, covers the period from the program's inception in the mid-1950s through 1982. Written in non-technical language, the history is addressed to both the general public and those more specialized in nuclear and space technologies. 19 figs., 3 tabs.

  5. DOE Space Allocation Standard | Department of Energy

    Energy Savers [EERE]

    Space Allocation Standard DOE Space Allocation Standard PDF icon 2011.10.13 DOE Space Allocation Standard.pdf More Documents & Publications Aggregating QECB Allocations and Using QECBs to Support the Private Sector: A Case Study on Massachusetts CX-007095: Categorical Exclusion Determination CX-007096: Categorical Exclusion Determination

  6. Building America Webinar: Retrofitting Central Space Conditioning

    Energy Savers [EERE]

    Strategies for Multifamily Buildings | Department of Energy Retrofitting Central Space Conditioning Strategies for Multifamily Buildings Building America Webinar: Retrofitting Central Space Conditioning Strategies for Multifamily Buildings The webinar on July 16, 2014, focused on improving the performance of central space conditioning systems in multifamily buildings. Presenters discussed hydronic heating strategies and the evaluation of thermostatically controlled radiator valves (TRVs).

  7. Small Space Heater Basics | Department of Energy

    Energy Savers [EERE]

    Small Space Heater Basics Small Space Heater Basics August 19, 2013 - 10:38am Addthis Small space heaters, also called portable heaters, are typically used when the main heating system is inadequate or when central heating is too costly to install or operate. Space heater capacities generally range between 10,000 Btu to 40,000 Btu per hour. Common fuels used for this purpose are electricity, propane, natural gas, and kerosene. Although most space heaters rely on convection (the circulation of

  8. Preventing Space Traffic Jams | Department of Energy

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

    Preventing Space Traffic Jams Preventing Space Traffic Jams June 10, 2015 - 2:25pm Addthis With around one thousand active satellites and the tens of thousands of pieces of space junk orbiting Earth, space is getting exceedingly crowded. Researchers at Lawrence Livermore National Lab are working on a system that could help prevent collisions in space. | Graphic by <a href="/node/379579">Sarah Gerrity</a>, Energy Department. With around one thousand active satellites and the

  9. Origin of matter and space-time in the big bang

    SciTech Connect (OSTI)

    Mathews, G. J.; Yamazaki, D.; Kusakabe, M.; Cheoun, M.-K.

    2014-05-02

    We review the case for and against a bulk cosmic motion resulting from the quantum entanglement of our universe with the multiverse beyond our horizon. Within the current theory for the selection of the initial state of the universe from the landscape multiverse there is a generic prediction that pre-inflation quantum entanglement with other universes should give rise to a cosmic bulk flow with a correlation length of order horizon size and a velocity field relative to the expansion frame of the universe. Indeed, the parameters of this motion are are tightly constrained. A robust prediction can be deduced indicating that there should be an overall motion of of about 800 km/s relative to the background space time as defined by the cosmic microwave background (CMB). This talk will summarize the underlying theoretical motivation for this hypothesis. Of course our motion relative to the background space time (CMB dipole) has been known for decades and is generally attributed to the gravitational pull of the local super cluster. However, this cosmic peculiar velocity field has been recently deduced out to very large distances well beyond that of the local super cluster by using X-ray galaxy clusters as tracers of matter motion. This is achieved via the kinematic component of the Sunyaev-Zeldovich (KSZ) effect produced by Compton scattering of cosmic microwave background photons from the local hot intracluster gas. As such, this method measures peculiar velocity directly in the frame of the cluster. Similar attempts by our group and others have attempted to independently assess this bulk flow via Type la supernova redshifts. In this talk we will review the observation case for and against the existence of this bulk flow based upon the observations and predictions of the theory. If this interpretation is correct it has profound implications in that we may be observing for the first time both the physics that occurred before the big bang and the existence of the multiverse beyond our horizon.

  10. Legacy extragalactic UV survey (LEGUS) with the Hubble space telescope. I. Survey description

    SciTech Connect (OSTI)

    Calzetti, D.; Andrews, J. E.; Lee, J. C.; Sabbi, E.; Ubeda, L.; Bright, S. N.; Aloisi, A.; Brown, T. M.; Christian, C.; Cignoni, M.; Adamo, A.; Smith, L. J.; Chandar, R.; Clayton, G. C.; Silva, R. da; Mink, S. E. de; Dobbs, C.; Elmegreen, B. G.; Elmegreen, D. M.; and others

    2015-02-01

    The Legacy ExtraGalactic UV Survey (LEGUS) is a Cycle 21 Treasury program on the Hubble Space Telescope aimed at the investigation of star formation and its relation with galactic environment in nearby galaxies, from the scales of individual stars to those of ?kiloparsec-size clustered structures. Five-band imaging from the near-ultraviolet to the I band with the Wide-Field Camera 3 (WFC3), plus parallel optical imaging with the Advanced Camera for Surveys (ACS), is being collected for selected pointings of 50 galaxies within the local 12 Mpc. The filters used for the observations with the WFC3 are F275W(?2704 ?), F336W(?3355 ?), F438W(?4325 ?), F555W(?5308 ?), and F814W(?8024 ?); the parallel observations with the ACS use the filters F435W(?4328 ?), F606W(?5921 ?), and F814W(?8057 ?). The multiband images are yielding accurate recent (?50 Myr) star formation histories from resolved massive stars and the extinction-corrected ages and masses of star clusters and associations. The extensive inventories of massive stars and clustered systems will be used to investigate the spatial and temporal evolution of star formation within galaxies. This will, in turn, inform theories of galaxy evolution and improve the understanding of the physical underpinning of the gasstar formation relation and the nature of star formation at high redshift. This paper describes the survey, its goals and observational strategy, and the initial scientific results. Because LEGUS will provide a reference survey and a foundation for future observations with the James Webb Space Telescope and with ALMA, a large number of data products are planned for delivery to the community.

  11. Survivable pulse power space radiator

    DOE Patents [OSTI]

    Mims, J.; Buden, D.; Williams, K.

    1988-03-11

    A thermal radiator system is described for use on an outer space vehicle, which must survive a long period of nonuse and then radiate large amounts of heat for a limited period of time. The radiator includes groups of radiator panels that are pivotally connected in tandem, so that they can be moved to deployed configuration wherein the panels lie largely coplanar, and to a stowed configuration wherein the panels lie in a stack to resist micrometerorite damage. The panels are mounted on a boom which separates a hot power source from a payload. While the panels are stowed, warm fluid passes through their arteries to keep them warm enough to maintain the coolant in a liquid state and avoid embrittlement of material. The panels can be stored in a largely cylindrical shell, with panels progressively further from the boom being of progressively shorter length. 5 figs.

  12. Survivable pulse power space radiator

    DOE Patents [OSTI]

    Mims, James (Albuquerque, NM); Buden, David (Albuquerque, NM); Williams, Kenneth (Albuquerque, NM)

    1989-01-01

    A thermal radiator system is described for use on an outer space vehicle, which must survive a long period of nonuse and then radiate large amounts of heat for a limited period of time. The radiator includes groups of radiator panels that are pivotally connected in tandem, so that they can be moved to deployed configuration wherein the panels lie largely coplanar, and to a stowed configuration wherein the panels lie in a stack to resist micrometeorite damage. The panels are mounted on a boom which separates a hot power source from a payload. While the panels are stowed, warm fluid passes through their arteries to keep them warm enough to maintain the coolant in a liquid state and avoid embrittlement of material. The panels can be stored in a largely cylindrical shell, with panels progressively further from the boom being of progressively shorter length.

  13. COSMIC FLOW FROM TWO MICRON ALL-SKY REDSHIFT SURVEY: THE ORIGIN OF COSMIC MICROWAVE BACKGROUND DIPOLE AND IMPLICATIONS FOR LAMBDACDM COSMOLOGY

    SciTech Connect (OSTI)

    Lavaux, Guilhem; Mohayaee, Roya; Colombi, Stephane

    2010-01-20

    We generate the peculiar velocity field for the Two Micron All-Sky Redshift Survey (2MRS) catalog using an orbit-reconstruction algorithm. The reconstructed velocities of individual objects in 2MRS are well correlated with the peculiar velocities obtained from high-precision observed distances within 3000 km s{sup -1}. We estimate the mean matter density to be OMEGA{sub m} = 0.31 +- 0.05 by comparing observed to reconstructed velocities in this volume. The reconstructed motion of the Local Group in the rest frame established by distances within 3000 km s{sup -1} agrees with the observed motion and is generated by fluctuations within this volume, in agreement with observations. Having tested our method against observed distances, we reconstruct the velocity field of 2MRS in successively larger radii, to study the problem of convergence toward the cosmic microwave background (CMB) dipole. We find that less than half of the amplitude of the CMB dipole is generated within a volume enclosing the Hydra-Centaurus-Norma supercluster at around 40 h {sup -1} Mpc. Although most of the amplitude of the CMB dipole seems to be recovered by 120 h {sup -1} Mpc, the direction does not agree and hence we observe no convergence up to this scale. Due to dominant superclusters such as Shapley or Horologium-Reticulum in the southern hemisphere at scales above 120 h {sup -1} Mpc, one might need to go well beyond 200 h {sup -1} Mpc to fully recover the dipole vector. We develop a statistical model which allows us to estimate cosmological parameters from the reconstructed growth of convergence of the velocity of the Local Group toward the CMB dipole motion. For scales up to 60 h {sup -1} Mpc, assuming a Local Group velocity of 627 km s{sup -1}, we estimate OMEGA{sub m} h {sup 2} = 0.11 +- 0.06 and sigma{sub 8} = 0.9 +- 0.4, in agreement with WMAP5 measurements at the 1sigma level. However, for scales up to 100 h {sup -1} Mpc, we obtain OMEGA{sub m} h {sup 2} = 0.08 +- 0.03 and sigma{sub 8} = 1.0 +- 0.4, which agrees at the 1sigma to 2sigma level with WMAP5 results.

  14. NASA Marshall Space Flight Center Improves Cooling System Performance...

    Energy Savers [EERE]

    NASA Marshall Space Flight Center Improves Cooling System Performance NASA Marshall Space Flight Center Improves Cooling System Performance NASA Marshall Space Flight Center...

  15. National Aeronautics and Space Administration | Open Energy Informatio...

    Open Energy Info (EERE)

    Aeronautics and Space Administration Jump to: navigation, search Logo: National Aeronautics and Space Administration Name: National Aeronautics and Space Administration Address:...

  16. Los Alamos Space Weather Summer School

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

    Overview Program Details Local Information Apply Application Process Eligibility Criteria General Information for Applicants Information for Non-U.S Citizens Mentors, Projects Lectures Papers, Reports Photos NSEC » CSES » Space Weather Summer School Los Alamos Space Weather Summer School June 6 - July 29, 2016 Contacts Director Misa Cowee Email Administrative Assistant Mary Wubbena Email Request more information Email Los Alamos Space Weather Summer School 4:05 Applications for the 2016

  17. Lab celebrates 50 years in space

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

    celebrates 50 years in space Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue:Mar. 2016 all issues All Issues » submit Lab celebrates 50 years in space National security missions and pure research December 1, 2013 Lab celebrates 50 years in space Lab's instruments have helped detect possible nuclear weapon detonations and led to fundamental scientific discoveries. Contacts Community Programs Office Director Kurt Steinhaus Email Editor

  18. Space Nuclear MIssion History | Department of Energy

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

    Power Systems » Space Nuclear MIssion History Space Nuclear MIssion History A HISTORY OF MISSION SUCCESSES For over fifty years, the Department of Energy has enabled space exploration on 27 missions by providing safe reliable radioistope power systems and radioisotope heater units for NASA, Navy, Air Force, DOE. Mission Year Launched Agency Regions Explored Transit 4a 1961 Navy Earth- Navy Navigation Satelitte Transit 4B 1961 Navy Earth - Navigation Satelitte Transit 5-BN-1 1963 Navy Earth -

  19. Total Space Heating Water Heating Cook-

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    (million gallons) Fuel Oil Energy Intensity (gallonssquare foot) Energy-Related Space Functions (more than one may apply) Commercial Food Preparation.... 860 720 87 Q 41...

  20. Space Conditioning Standing Technical Committee Strategic Plan...

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

    Committee Strategic Plan Space Conditioning Standing Technical Committee Strategic Plan This strategic plan document outlines the gaps, barriers, and opportunities identified by...

  1. Building America Webinar: High Performance Space Conditioning...

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

    II Building America Webinar: High Performance Space Conditioning Systems, Part II The webinar on Nov. 18, 2014, continued the series on strategies to improve the performance of ...

  2. Solar space cooling | Open Energy Information

    Open Energy Info (EERE)

    Solar space cooling Jump to: navigation, search Solarcooling.jpg Contents 1 Introduction 2 Solar Absorption Technology 3 Solar Desiccant Technology 4 Passive Solar Cooling 5...

  3. Solar space heating | Open Energy Information

    Open Energy Info (EERE)

    Solar space heating (Redirected from - Solar Ventilation Preheat) Jump to: navigation, search (The following text is derived from the United States Department of Energy's...

  4. Building America Webinar: High Performance Space Conditioning...

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

    Air Distribution Retrofit Strategies for Affordable Housing Building America Webinar: High Performance Space Conditioning Systems, Part II - Air Distribution Retrofit Strategies ...

  5. Space Energy Corporation | Open Energy Information

    Open Energy Info (EERE)

    Jump to: navigation, search Name: Space Energy Corporation Place: Tokyo, Tokyo, Japan Zip: 110-0005 Product: Japanese integrated manufacturer of PV wafers; ingots are...

  6. National Aeronautics and Space Administration Technology Marketing...

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

    National Aeronautics and Space Administration Technology Marketing Summaries Here you'll find marketing summaries for technologies available for licensing from the National...

  7. EMISSION-LINE GALAXIES FROM THE HUBBLE SPACE TELESCOPE PROBING EVOLUTION AND REIONIZATION SPECTROSCOPICALLY (PEARS) GRISM SURVEY. II. THE COMPLETE SAMPLE

    SciTech Connect (OSTI)

    Pirzkal, Nor; Rothberg, Barry; Ly, Chun; Grogin, Norman A.; Dahlen, Tomas; Noeske, Kai G.; Bellini, Andrea; Malhotra, Sangeeta; Rhoads, James E.; Cohen, Seth H.; Mechtley, Matthew; Windhorst, Rogier A.; Meurer, Gerhardt R.; Walsh, Jeremy R.; Hathi, Nimish P.; Holwerda, Benne W.; Straughn, Amber N.

    2013-07-20

    We present a full analysis of the Probing Evolution And Reionization Spectroscopically (PEARS) slitess grism spectroscopic data obtained with the Advanced Camera for Surveys on board Hubble Space Telescope. PEARS covers fields within both the Great Observatories Origins Deep Survey (GOODS) North and South fields, making it ideal as a random survey of galaxies, as well as the availability of a wide variety of ancillary observations complemented by the spectroscopic results. Using the PEARS data, we are able to identify star-forming galaxies (SFGs) within the redshift volume 0 < z < 1.5. Star-forming regions in the PEARS survey are pinpointed independently of the host galaxy. This method allows us to detect the presence of multiple emission-line regions (ELRs) within a single galaxy. We identified a total of 1162 H{alpha}, [O III], and/or [O II] emission lines in the PEARS sample of 906 galaxies to a limiting flux of {approx}10{sup -18} erg s{sup -1} cm{sup -2}. The ELRs have also been compared to the properties of the host galaxy, including morphology, luminosity, and mass. From this analysis, we find three key results: (1) the computed line luminosities show evidence of a flattening in the luminosity function with increasing redshift; (2) the star-forming systems show evidence of complex morphologies with star formation occurring predominantly within one effective (half-light) radius. However, the morphologies show no correlation with host stellar mass. (3) Also, the number density of SFGs with M{sub *} {>=} 10{sup 9} M{sub Sun} decreases by an order of magnitude at z {<=} 0.5 relative to the number at 0.5 < z < 0.9, supporting the argument of galaxy downsizing.

  8. Eddy current measurement of tube element spacing

    DOE Patents [OSTI]

    Latham, Wayne Meredith (Forest, VA); Hancock, Jimmy Wade (Lynchburg, VA); Grut, Jayne Marie (Madison Heights, VA)

    1998-01-01

    A method of electromagnetically measuring the distance between adjacent tube elements in a heat exchanger. A cylindrical, high magnetic permeability ferrite slug is placed in the tube adjacent the spacing to be measured. A bobbin or annular coil type probe operated in the absolute mode is inserted into a second tube adjacent the spacing to be measured. From prior calibrations on the response of the eddy current coil, the signals from the coil, when sensing the presence of the ferrite slug, are used to determine the spacing between the tubes.

  9. ION SOURCE WITH SPACE CHARGE NEUTRALIZATION

    DOE Patents [OSTI]

    Flowers, J.W.; Luce, J.S.; Stirling, W.L.

    1963-01-22

    This patent relates to a space charge neutralized ion source in which a refluxing gas-fed arc discharge is provided between a cathode and a gas-fed anode to provide ions. An electron gun directs a controlled, monoenergetic electron beam through the discharge. A space charge neutralization is effected in the ion source and accelerating gap by oscillating low energy electrons, and a space charge neutralization of the source exit beam is effected by the monoenergetic electron beam beyond the source exit end. The neutralized beam may be accelerated to any desired energy at densities well above the limitation imposed by Langmuir-Child' s law. (AEC)

  10. Virtual tour: INL's space battery facility

    ScienceCinema (OSTI)

    Johnson, Steve

    2013-05-28

    This virtual tour shows how INL fuels and tests nuclear power systems for deep space missions. To learn more about INL's contribution to the Mars Science Laboratory, visit http://www.inl.gov/marsrover.

  11. Open Space Stewardship Program 2013 Celebration

    Office of Energy Efficiency and Renewable Energy (EERE)

    Students in grades K through 12 are involved in authentic environmental research on properties in their own communities, fostering a sense of ownership and responsibility for open space within...

  12. Open Space Stewardship Workshop for Secondary Teachers

    Broader source: Energy.gov [DOE]

    This practical, hands-on workshop provides an opportunity to experience the equipment and field techniques that are useful in Open Space Stewardship Program. The four day workshop (July 15-19 2013)...

  13. Hanford Site Confined Space Procedure (HSCSP)

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

    requirements. 2.3 Added "confined" before "space" in bullet 2 and 8. 2.3 Modified language in bullet 5 from "until relieved by another attendant" to "until relieved of their...

  14. Stellar science unveiled at space conference

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

    Stellar science unveiled at space conference Stellar science unveiled at space conference The Laboratory will be represented in more than 20 papers to be given at the 42nd Lunar and Planetary Science Conference in Houston. March 8, 2011 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials.

  15. Optimum phase space probabilities from quantum tomography

    SciTech Connect (OSTI)

    Roy, Arunabha S.; Roy, S. M.

    2014-01-15

    We determine a positive normalised phase space probability distribution P with minimum mean square fractional deviation from the Wigner distribution W. The minimum deviation, an invariant under phase space rotations, is a quantitative measure of the quantumness of the state. The positive distribution closest to W will be useful in quantum mechanics and in time frequency analysis. The position-momentum correlations given by the distribution can be tested experimentally in quantum optics.

  16. Observations and simulations improve space weather models

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

    Observations improve space weather models Observations and simulations improve space weather models Researchers used data from the Van Allen Probes to improve a three-dimensional model created by Los Alamos scientists called DREAM3D. June 25, 2014 NASA's Van Allen Probes sample the Earth's magnetosphere. NASA's Van Allen Probes sample the Earth's magnetosphere. The work demonstrated that DREAM3D accurately simulated the behavior of a complex and dynamic event in the radiation belt that was

  17. Observations and simulations improve space weather models

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

    Observations improve space weather models Observations and simulations improve space weather models Researchers used data from the Van Allen Probes to improve a three-dimensional model created by Los Alamos scientists called DREAM3D. June 25, 2014 NASA's Van Allen Probes sample the Earth's magnetosphere. NASA's Van Allen Probes sample the Earth's magnetosphere. The work demonstrated that DREAM3D accurately simulated the behavior of a complex and dynamic event in the radiation belt that was

  18. Los Alamos imager aboard IBEX space mission

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

    Imager aboard IBEX space mission Los Alamos imager aboard IBEX space mission This is the first in a new series of talks that will focus on the emerging scientific field of quantitative biology. October 17, 2008 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National

  19. Center for Space and Earth Science

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

    Institute of Geophysics, Planetary Physics, and Signatures Center for Space and Earth Science Promoting and supporting high-quality, cutting-edge science in the areas of astrophysics, space physics, solid planetary geoscience, and climate science. Contact Director Reiner Friedel (505) 665-1936 Email Professional Staff Assistant Georgia Sanchez (505) 665-0855 Email Astophysics and Cosmology Hui Li (505) 665-3131 Email Climate Keeley Costigan (505) 665-4788 Email Geophysics David Coblentz (505)

  20. Small Reactor for Deep Space Exploration

    SciTech Connect (OSTI)

    2012-11-29

    This is the first demonstration of a space nuclear reactor system to produce electricity in the United States since 1965, and an experiment demonstrated the first use of a heat pipe to cool a small nuclear reactor and then harvest the heat to power a Stirling engine at the Nevada National Security Site's Device Assembly Facility confirms basic nuclear reactor physics and heat transfer for a simple, reliable space power system.

  1. Building America Webinar: Retrofitting Central Space Conditioning

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

    Strategies for Multifamily Buildings - Introduction | Department of Energy Introduction Building America Webinar: Retrofitting Central Space Conditioning Strategies for Multifamily Buildings - Introduction This presentation serves as the introduction to the Building America webinar held on July 16, 2014, and provided information about mproving the performance of central space conditioning systems in multifamily buildings. PDF icon BA_webinar_intro_7-16-14.pdf More Documents &

  2. Simplified Space Conditioning in Low Load Homes

    Energy Savers [EERE]

    Simplified Space Conditioning in Low Load Homes Andrew Poerschke IBACOS, Inc. BA Webinar October, 2014 Overview * Define the problem * Define thermal comfort * Discuss solutions * Case Studies - Cold Climate Unoccupied Lab House - Hot Climate Occupied Test House Smaller Loads, same size home 7 Tons 2800 CFM 3663 sq ft 3 Tons 1200 CFM 3663 sq ft Benchmark ZERH Here is the problem - Though loads are smaller, same floor plan and geometry makes it difficult to condition space with less CFM. -

  3. Small Reactor for Deep Space Exploration

    ScienceCinema (OSTI)

    none,

    2014-05-30

    This is the first demonstration of a space nuclear reactor system to produce electricity in the United States since 1965, and an experiment demonstrated the first use of a heat pipe to cool a small nuclear reactor and then harvest the heat to power a Stirling engine at the Nevada National Security Site's Device Assembly Facility confirms basic nuclear reactor physics and heat transfer for a simple, reliable space power system.

  4. Coexistence of Weak Ferromagnetism and Polar Lattice Distortion in Epitaxial NiTiO3 thin films of the LiNbO3-Type Structure

    SciTech Connect (OSTI)

    Varga, Tamas; Droubay, Timothy C.; Bowden, Mark E.; Colby, Robert J.; Manandhar, Sandeep; Shutthanandan, V.; Hu, Dehong; Kabius, Bernd C.; Apra, Edoardo; Shelton, William A.; Chambers, Scott A.

    2013-04-15

    We report the magnetic and structural characteristics of epitaxial NiTiO3 films grown by pulsed laser deposition that are isostructural with acentric LiNbO3 (space group R3c). Optical second harmonic generation and magnetometry demonstrate lattice polarization at room temperature and weak ferromagnetism below 250 K, respectively. These results appear to be consistent with earlier predictions from first-principles calculations of the coexistence of ferroelectricity and weak ferromagnetism in a series of transition metal titanates crystallizing in the LiNbO3 structure. This acentric form of NiTiO3 is believed to be one of the rare examples of ferroelectrics exhibiting weak ferromagnetism generated by a Dzyaloshinskii-Moriya interaction.

  5. Lattice distortions and octahedral rotations in epitaxially strained LaNiO{sub 3}/LaAlO{sub 3} superlattices

    SciTech Connect (OSTI)

    Kinyanjui, M. K. E-mail: benckise@fkf.mpg.de; Kaiser, U.; Lu, Y.; Wu, M.; Wochner, P.; Christiani, G.; Logvenov, G.; Habermeier, H.-U.; Keimer, B.; Benckiser, E. E-mail: benckise@fkf.mpg.de; Gauquelin, N.; Botton, G. A.; Frano, A.; Reehuis, M.

    2014-06-02

    Using a complementary combination of x-ray diffraction and atomically resolved imaging we investigated the lattice structure of epitaxial LaNiO{sub 3}/LaAlO{sub 3} superlattices grown on a compressive-strain inducing LaSrAlO{sub 4} (001) substrate. A refinement of the structure obtained from the x-ray data revealed the monoclinic I 2/c 1 1 space group. The (Ni/Al)O{sub 6} octahedral rotation angle perpendicular to the superlattice plane is enhanced, and the one parallel to the plane is reduced with respect to the corresponding bulk values. High-angle annular dark field imaging was used to determine the lattice parameters within the superlattice unit cell. High-resolution electron microscopy images of the oxygen atoms are consistent with the x-ray results.

  6. Flying on Sun Shine: Sailing in Space

    SciTech Connect (OSTI)

    Alhorn, Dean

    2012-03-28

    On January 20th, 2011, NanoSail-D successfully deployed its sail in space. It was the first solar sail vehicle to orbit the earth and the second sail ever unfurled in space. The 10m2 sail, deployment mechanism and electronics were packed into a 3U CubeSat with a volume of about 3500cc. The NanoSail-D mission had two objectives: eject a nanosatellite from a minisatellite; deploy its sail from a highly compacted volume to validate large structure deployment and potential de-orbit technologies. NanoSail-D was jointly developed by NASA's Marshall Space Flight Center and Ames Research Center. The ManTech/NeXolve Corporation provided key sail design support. NanoSail-D is managed by Marshall and jointly sponsored by the Army Space and Missile Defense Command, the Space Test Program, the Von Braun Center for Science and Innovation and Dynetics Inc. The presentation will provide insights into sailcraft advances and potential missions enabled by this emerging in-space propulsion technology.

  7. Infrared Multiphoton Dissociation Spectroscopy of a Gas-Phase Complex of Uranyl and 3-Oxa-Glutaramide: An Extreme Red-Shift of the [O=U=O]? Asymmetric Stretch

    SciTech Connect (OSTI)

    Gibson, John K.; Hu, Hanshi; Van Stipdonk, Michael J.; Berden, Giel; Oomens, Jos; Li, Jun

    2015-04-09

    The gas-phase complex UO?(TMOGA)?? (TMOGA = tetramethyl-3-oxa-glutaramide) prepared by electrospray ionization was characterized by infrared multiphoton dissociation (IRMPD) spectroscopy. The IRMPD spectrum from 7001800 cm? was interpreted using a computational study based on density functional theory. The predicted vibrational frequencies are in good agreement with the measured values, with an average deviation of only 8 cm? (<1%) and a maximum deviation of 21 cm? (<2%). The only IR peak assigned to the linear uranyl moiety was the asymmetric ?? mode, which appeared at 965 cm? and was predicted by DFT as 953 cm?. This ?? frequency is red-shifted relative to bare uranyl, UO??, by ca. 150 cm? due to electron donation from the TMOGA ligands. Based on the degree of red-shifting, it is inferred that two TMOGA oxygen-donor ligands have a greater effective gas basicity than the four monodentate acetone ligands in UO?(acetone)??. The uranyl ?? frequency was also computed for uranyl coordinated by two TMGA ligands, in which the central Oether of TMOGA has been replaced by CH?. The computed ?? for UO?(TMGA)??, 950 cm?, is essentially the same as that for UO?(TMOGA)??, suggesting that electron donation to uranyl from the Oether of TMOGA is minor. The computed ?? asymmetric stretching frequencies for the three actinyl complexes, UO?(TMOGA)??, NpO?(TMOGA)?? and PuO?(TMOGA)??, are comparable. This similarity is discussed in the context of the relationship between ?? and intrinsic actinide-oxygen bond energies in actinyl complexes.

  8. 1999 Commercial Buildings Characteristics--Glossary--Space-Heating...

    U.S. Energy Information Administration (EIA) Indexed Site

    Space-Heating Equipment Glossary-Space-Heating Equipment Boiler: A type of space-heating equipment consisting of a vessel or tank where heat produced from the combustion of such...

  9. Building America Webinar: High Performance Space Conditioning Systems, Part

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

    I: Simplified Space Conditioning in Low Load Homes | Department of Energy I: Simplified Space Conditioning in Low Load Homes Building America Webinar: High Performance Space Conditioning Systems, Part I: Simplified Space Conditioning in Low Load Homes This presentation is titled, Simplified Space Conditioning in Low-load Homes, presented by Andrew Poerschke of IBACOS. The presentation will focus on what is "simple" when it comes to space conditioning. As loads in houses (new and

  10. Structural distortions in the spin-gap regime of the quantum antiferromagnet SrCu{sub 2}(BO{sub 3}){sub 2}

    SciTech Connect (OSTI)

    Vecchini, C.; Adamopoulos, O.; Chapon, L.C.; Lappas, A.; Kageyama, H.; Ueda, Y.; Zorko, A.

    2009-12-15

    We report the first crystallographic study within the low-temperature (<40 K) spin-gap region of the two-dimensional frustrated antiferromagnet SrCu{sub 2}(BO{sub 3}){sub 2}. The crystal system does not deviate from the tetragonal I-42m space group symmetry. However, our high-resolution neutron powder diffraction measurements uncover subtle structural modifications below 34 K, concomitant to the formation of the dimer singlet ground state. Intimate spin-lattice coupling leads to negative thermal expansion of the tetragonal structure, which reflects into particular local lattice adjustments. The extracted structural parameters suggest the reduction of the buckling found in the copper-borate planes and the strengthening of the leading, in-plane intra-dimer superexchange interaction. The observed contraction along the c-axis, associated with the inter-dimer exchange in adjacent layers, indicates the involvement of weaker three-dimensional interactions in the magnetic properties. The rules posed by the crystal symmetry do not preclude Dzyaloshinsky-Moriya interactions, which therefore remain as an important source of spin anisotropy necessary to rationalise the ground state behaviour. - Abstract: We report the first crystallographic study within the low-temperature spin-gap region of the two-dimensional frustrated antiferromagnet SrCu{sub 2}(BO{sub 3}){sub 2}. Subtle spin-lattice coupling was unveiled in the low-temperature region. Display Omitted

  11. Hi-Tech Fisheries Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Hi-Tech Fisheries Space Heating Low Temperature Geothermal Facility Facility Hi-Tech Fisheries...

  12. Minimized Space Conditioning Distribution Strategy for Low-load...

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

    Minimized Space Conditioning Distribution Strategy for Low-load Homes Minimized Space Conditioning Distribution Strategy for Low-load Homes This presentation was given at the...

  13. Agua Calientes Trailer Park Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Park Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Agua Calientes Trailer Park Space Heating Low Temperature Geothermal Facility Facility Agua...

  14. LEDSGP/Agriculture Work Space/Tools | Open Energy Information

    Open Energy Info (EERE)

    LEDSGPAgriculture Work SpaceTools < LEDSGP(Redirected from Agriculture Work SpaceTools) Jump to: navigation, search Low Emission Development Strategies Global Partnership...

  15. Eigenfunction Expansion of the Space-Time Dependent Neutron Survival...

    Office of Scientific and Technical Information (OSTI)

    Eigenfunction Expansion of the Space-Time Dependent Neutron Survival Probability. Citation Details In-Document Search Title: Eigenfunction Expansion of the Space-Time Dependent...

  16. Canon City Area Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Canon City Area Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Canon City Area Space Heating Low Temperature Geothermal Facility Facility Canon...

  17. Klamath County Shops Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Shops Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Klamath County Shops Space Heating Low Temperature Geothermal Facility Facility Klamath...

  18. Hunters Hot Spring Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Hot Spring Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Hunters Hot Spring Space Heating Low Temperature Geothermal Facility Facility Hunters...

  19. Modoc High School Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    High School Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Modoc High School Space Heating Low Temperature Geothermal Facility Facility Modoc...

  20. Medical Center Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Medical Center Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Medical Center Space Heating Low Temperature Geothermal Facility Facility Medical...

  1. Corral Space Heating Low Temperature Geothermal Facility | Open...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Corral Space Heating Low Temperature Geothermal Facility Facility Corral Sector Geothermal energy...

  2. The Wilderness Lodge Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name The Wilderness Lodge Space Heating Low Temperature Geothermal Facility Facility The Wilderness...

  3. Boulder Hot Springs Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Boulder Hot Springs Space Heating Low Temperature Geothermal Facility Facility Boulder Hot...

  4. Manley Hot Springs Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Manley Hot Springs Space Heating Low Temperature Geothermal Facility Facility Manley Hot Springs...

  5. Jump Steady Resort Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Jump Steady Resort Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Jump Steady Resort Space Heating Low Temperature Geothermal Facility Facility...

  6. Circle Hot Springs Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Circle Hot Springs Space Heating Low Temperature Geothermal Facility Facility Circle Hot Springs...

  7. Klamath Schools (7) Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Schools (7) Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Klamath Schools (7) Space Heating Low Temperature Geothermal Facility Facility...

  8. Health Spa Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Spa Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Health Spa Space Heating Low Temperature Geothermal Facility Facility Glenwood Springs Health...

  9. Desert Hot Springs Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Springs Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Desert Hot Springs Space Heating Low Temperature Geothermal Facility Facility Desert Hot...

  10. Vale Residences Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Residences Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Vale Residences Space Heating Low Temperature Geothermal Facility Facility Vale...

  11. Twin Peaks Motel Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Peaks Motel Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Twin Peaks Motel Space Heating Low Temperature Geothermal Facility Facility Twin...

  12. Lava Hot Springs Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Lava Hot Springs Space Heating Low Temperature Geothermal Facility Facility Lava Hot Springs...

  13. Hot Sulphur Springs Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Hot Sulphur Springs Space Heating Low Temperature Geothermal Facility Facility Hot Sulphur...

  14. Medical Hot Springs Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Medical Hot Springs Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Medical Hot Springs Space Heating Low Temperature Geothermal Facility...

  15. Space Dust Analysis Could Provide Clues to Solar System Origins

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

    Space Dust Analysis Could Provide Clues to Solar System Origins Print New studies of space dust captured by NASA's Stardust Interstellar Dust Collector have shown that interstellar...

  16. Klamath Residence (500) Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Residence (500) Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Klamath Residence (500) Space Heating Low Temperature Geothermal Facility...

  17. Broadwater Athletic Club & Hot Springs Space Heating Low Temperature...

    Open Energy Info (EERE)

    Broadwater Athletic Club & Hot Springs Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Broadwater Athletic Club & Hot Springs Space Heating Low...

  18. Van Norman Residences Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Norman Residences Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Van Norman Residences Space Heating Low Temperature Geothermal Facility...

  19. Cottonwood Hot Springs Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Hot Springs Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Cottonwood Hot Springs Space Heating Low Temperature Geothermal Facility Facility...

  20. Cedarville Elementary & High School Space Heating Low Temperature...

    Open Energy Info (EERE)

    Cedarville Elementary & High School Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Cedarville Elementary & High School Space Heating Low...

  1. Stroppel Hotel Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Stroppel Hotel Space Heating Low Temperature Geothermal Facility Facility Stroppel Hotel Sector...

  2. Tecopa Hot Springs Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Tecopa Hot Springs Space Heating Low Temperature Geothermal Facility Facility Tecopa Hot Springs...

  3. Walley's Hot Springs Resort Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Walley's Hot Springs Resort Space Heating Low Temperature Geothermal Facility Facility Walley's...

  4. Vale Slaughter House Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Slaughter House Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Vale Slaughter House Space Heating Low Temperature Geothermal Facility Facility...

  5. Arrowhead Hot Springs Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Hot Springs Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Arrowhead Hot Springs Space Heating Low Temperature Geothermal Facility Facility...

  6. Box Canyon Motel Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Canyon Motel Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Box Canyon Motel Space Heating Low Temperature Geothermal Facility Facility Box...

  7. Melozi Space Heating Low Temperature Geothermal Facility | Open...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Melozi Space Heating Low Temperature Geothermal Facility Facility Melozi Sector Geothermal energy...

  8. Fairmont Hot Springs Resort Space Heating Low Temperature Geothermal...

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    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Fairmont Hot Springs Resort Space Heating Low Temperature Geothermal Facility Facility Fairmont...

  9. Salida Hot Springs (Poncha Spring) Space Heating Low Temperature...

    Open Energy Info (EERE)

    Salida Hot Springs (Poncha Spring) Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Salida Hot Springs (Poncha Spring) Space Heating Low...

  10. Maywood Industries of Oregon Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Maywood Industries of Oregon Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Maywood Industries of Oregon Space Heating Low Temperature...

  11. Lolo Hot Springs Resort Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Lolo Hot Springs Resort Space Heating Low Temperature Geothermal Facility Facility Lolo Hot...

  12. Henley High School Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Henley High School Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Henley High School Space Heating Low Temperature Geothermal Facility Facility...

  13. Vichy Hot Springs Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Vichy Hot Springs Space Heating Low Temperature Geothermal Facility Facility Vichy Hot Springs...

  14. Buckhorn Mineral Wells Space Heating Low Temperature Geothermal...

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    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Buckhorn Mineral Wells Space Heating Low Temperature Geothermal Facility Facility Buckhorn...

  15. Shoshone Motel & Trailer Park Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Motel & Trailer Park Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Shoshone Motel & Trailer Park Space Heating Low Temperature Geothermal...

  16. Baranof Space Heating Low Temperature Geothermal Facility | Open...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Baranof Space Heating Low Temperature Geothermal Facility Facility Baranof Sector Geothermal...

  17. Steamboat Villa Hot Springs Spa Space Heating Low Temperature...

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    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Steamboat Villa Hot Springs Spa Space Heating Low Temperature Geothermal Facility Facility...

  18. White Sulphur Springs Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Sulphur Springs Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name White Sulphur Springs Space Heating Low Temperature Geothermal Facility Facility...

  19. Waunita Hot Springs Ranch Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Waunita Hot Springs Ranch Space Heating Low Temperature Geothermal Facility Facility Waunita Hot...

  20. Twin Springs Resort Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Twin Springs Resort Space Heating Low Temperature Geothermal Facility Facility Twin Springs...

  1. Pagosa Springs Private Wells Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Private Wells Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Pagosa Springs Private Wells Space Heating Low Temperature Geothermal Facility...

  2. Merle West Medical Center Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Merle West Medical Center Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Merle West Medical Center Space Heating Low Temperature Geothermal...

  3. Olene Gap Space Heating Low Temperature Geothermal Facility ...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Olene Gap Space Heating Low Temperature Geothermal Facility Facility Olene Gap Sector Geothermal...

  4. Homestead Resort Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Resort Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Homestead Resort Space Heating Low Temperature Geothermal Facility Facility Homestead...

  5. Chico Hot Springs Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Chico Hot Springs Space Heating Low Temperature Geothermal Facility Facility Chico Hot Springs...

  6. Bell Island Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Bell Island Space Heating Low Temperature Geothermal Facility Facility Bell Island Sector...

  7. Mount Princeton Area Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Area Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Mount Princeton Area Space Heating Low Temperature Geothermal Facility Facility Mount...

  8. LDS Wardhouse Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Wardhouse Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name LDS Wardhouse Space Heating Low Temperature Geothermal Facility Facility LDS Wardhouse...

  9. Reno-Moana Area (300) Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Reno-Moana Area (300) Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Reno-Moana Area (300) Space Heating Low Temperature Geothermal Facility...

  10. Saratoga Springs Resort Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Saratoga Springs Resort Space Heating Low Temperature Geothermal Facility Facility Saratoga...

  11. Glenwood Hot Springs Lodge Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Lodge Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Glenwood Hot Springs Lodge Space Heating Low Temperature Geothermal Facility Facility...

  12. Hillbrook Nursing Home Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Hillbrook Nursing Home Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Hillbrook Nursing Home Space Heating Low Temperature Geothermal Facility...

  13. Indian Valley Hospital Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Hospital Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Indian Valley Hospital Space Heating Low Temperature Geothermal Facility Facility Indian...

  14. Chena Hot Springs Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Chena Hot Springs Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Chena Hot Springs Space Heating Low Temperature Geothermal Facility Facility...

  15. Ft Bidwell Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Ft Bidwell Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Ft Bidwell Space Heating Low Temperature Geothermal Facility Facility Ft Bidwell...

  16. Breitenbush Hot Springs Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Hot Springs Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Breitenbush Hot Springs Space Heating Low Temperature Geothermal Facility Facility...

  17. Bozeman Hot Springs Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Bozeman Hot Springs Space Heating Low Temperature Geothermal Facility Facility Bozeman Hot...

  18. Pinkerton Hot Springs Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Pinkerton Hot Springs Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Pinkerton Hot Springs Space Heating Low Temperature Geothermal Facility...

  19. Senior Citizens' Center Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Senior Citizens' Center Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Senior Citizens' Center Space Heating Low Temperature Geothermal Facility...

  20. Warm Springs State Hospital Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    State Hospital Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Warm Springs State Hospital Space Heating Low Temperature Geothermal Facility...

  1. Langel Valley Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Langel Valley Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Langel Valley Space Heating Low Temperature Geothermal Facility Facility Langel...

  2. LDS Church Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    LDS Church Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name LDS Church Space Heating Low Temperature Geothermal Facility Facility LDS Church...

  3. Klamath County Jail Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Jail Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Klamath County Jail Space Heating Low Temperature Geothermal Facility Facility Klamath...

  4. East Middle School and Cayuga Community College Space Heating...

    Open Energy Info (EERE)

    Middle School and Cayuga Community College Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name East Middle School and Cayuga Community College Space...

  5. Jemez Springs Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Jemez Springs Space Heating Low Temperature Geothermal Facility Facility Jemez Springs Sector...

  6. YMCA Space Heating Low Temperature Geothermal Facility | Open...

    Open Energy Info (EERE)

    YMCA Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name YMCA Space Heating Low Temperature Geothermal Facility Facility YMCA Sector Geothermal...

  7. Utah State Prison Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Prison Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Utah State Prison Space Heating Low Temperature Geothermal Facility Facility Utah State...

  8. Warner Springs Ranch Resort Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Ranch Resort Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Warner Springs Ranch Resort Space Heating Low Temperature Geothermal Facility...

  9. Surprise Valley Hospital Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Surprise Valley Hospital Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Surprise Valley Hospital Space Heating Low Temperature Geothermal...

  10. Del Rio Hot Springs Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Rio Hot Springs Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Del Rio Hot Springs Space Heating Low Temperature Geothermal Facility Facility...

  11. Miracle Hot Spring Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Spring Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Miracle Hot Spring Space Heating Low Temperature Geothermal Facility Facility Miracle Hot...

  12. St. Mary's Hospital Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Hospital Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name St. Mary's Hospital Space Heating Low Temperature Geothermal Facility Facility St....

  13. Cotulla High School Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Cotulla High School Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Cotulla High School Space Heating Low Temperature Geothermal Facility...

  14. Ouray Municipal Pool Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Municipal Pool Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Ouray Municipal Pool Space Heating Low Temperature Geothermal Facility Facility...

  15. Roosevelt Warm Springs Institute for Rehab. Space Heating Low...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Roosevelt Warm Springs Institute for Rehab. Space Heating Low Temperature Geothermal Facility...

  16. Miracle Hot Springs Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Miracle Hot Springs Space Heating Low Temperature Geothermal Facility Facility Miracle Hot...

  17. Marlin Hospital Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Marlin Hospital Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Marlin Hospital Space Heating Low Temperature Geothermal Facility Facility Marlin...

  18. Radium Hot Springs Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Radium Hot Springs Space Heating Low Temperature Geothermal Facility Facility Radium Hot Springs...

  19. Summer Lake Hot Springs Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Summer Lake Hot Springs Space Heating Low Temperature Geothermal Facility Facility Summer Lake...

  20. Banbury Hot Springs Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Banbury Hot Springs Space Heating Low Temperature Geothermal Facility Facility Banbury Hot...

  1. Peppermill Hotel Casino Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Peppermill Hotel Casino Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Peppermill Hotel Casino Space Heating Low Temperature Geothermal Facility...

  2. Modesto Memorial Hospital Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Memorial Hospital Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Modesto Memorial Hospital Space Heating Low Temperature Geothermal Facility...

  3. Indian Springs School Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    School Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Indian Springs School Space Heating Low Temperature Geothermal Facility Facility Indian...

  4. Geronimo Springs Museum Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Geronimo Springs Museum Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Geronimo Springs Museum Space Heating Low Temperature Geothermal Facility...

  5. Ophir Creek Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Ophir Creek Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Ophir Creek Space Heating Low Temperature Geothermal Facility Facility Ophir Creek...

  6. Burgdorf Hot Springs Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Burgdorf Hot Springs Space Heating Low Temperature Geothermal Facility Facility Burgdorf Hot...

  7. Hot Springs National Park Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    National Park Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Hot Springs National Park Space Heating Low Temperature Geothermal Facility...

  8. List of Passive Solar Space Heat Incentives | Open Energy Information

    Open Energy Info (EERE)

    Solar Space Heat Incentives Jump to: navigation, search The following contains the list of 282 Passive Solar Space Heat Incentives. CSV (rows 1 - 282) Incentive Incentive Type...

  9. Before House Committee on Science, Space, and Technology - Subcommitte...

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

    Committee on Science, Space, and Technology - Subcommittees on Environment and Energy Before House Committee on Science, Space, and Technology - Subcommittees on Environment and...

  10. ADMINISTRATIVE RECORDS SCHEDULE 11: SPACE AND MAINTENANCE RECORDS...

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

    1: SPACE AND MAINTENANCE RECORDS ADMINISTRATIVE RECORDS SCHEDULE 11: SPACE AND MAINTENANCE RECORDS This schedule provides for the disposal of all copies, wherever located in the ...

  11. Shared Space vs. In-Unit Upgrades in Multifamily Buildings |...

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

    Shared Space vs. In-Unit Upgrades in Multifamily Buildings Shared Space vs. In-Unit Upgrades in Multifamily Buildings Better Buildings Neighborhood Program Multifamily Peer...

  12. Hot Lake RV Park Space Heating Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Lake RV Park Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Hot Lake RV Park Space Heating Low Temperature Geothermal Facility Facility Hot Lake...

  13. James Webb Space Telescope: PM Lessons Applied - Eric Smith,...

    Energy Savers [EERE]

    James Webb Space Telescope: PM Lessons Applied - Eric Smith, Deputy Program Director, NASA James Webb Space Telescope: PM Lessons Applied - Eric Smith, Deputy Program Director,...

  14. Space Coast Next Generation Solar Energy Center Solar Power Plant...

    Open Energy Info (EERE)

    Coast Next Generation Solar Energy Center Solar Power Plant Jump to: navigation, search Name Space Coast Next Generation Solar Energy Center Solar Power Plant Facility Space Coast...

  15. Jackson Well Springs Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Jackson Well Springs Space Heating Low Temperature Geothermal Facility Facility Jackson Well...

  16. Jackson Hot Springs Lodge Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Jackson Hot Springs Lodge Space Heating Low Temperature Geothermal Facility Facility Jackson...

  17. Emittance and Phase Space Exchange for Advanced Beam Manipulation...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Emittance and Phase Space Exchange for Advanced Beam Manipulation and Diagnostics Citation Details In-Document Search Title: Emittance and Phase Space Exchange for...

  18. Emittance and Phase Space Exchange (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Emittance and Phase Space Exchange Citation Details In-Document Search Title: Emittance and Phase Space Exchange You are accessing a document from the Department of Energy's...

  19. Before the House Science, Space, and Technology Subcommittee...

    Energy Savers [EERE]

    House Science, Space, and Technology Subcommittee on Investigations and Oversight Before the House Science, Space, and Technology Subcommittee on Investigations and Oversight...

  20. Before the House Science, Space, and Technology Subcommittee...

    Energy Savers [EERE]

    Science, Space, and Technology Subcommittee on Energy and Environment Before the House Science, Space, and Technology Subcommittee on Energy and Environment Testimony of Scott...

  1. Klamath Apartment Buildings (13) Space Heating Low Temperature...

    Open Energy Info (EERE)

    (13) Space Heating Low Temperature Geothermal Facility Facility Klamath Apartment Buildings (13) Sector Geothermal energy Type Space Heating Location Klamath Falls, Oregon...

  2. National Air & Space Intelligence Center Holds Program About...

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

    National Air & Space Intelligence Center Holds Program About Empowering Women in the Workplace National Air & Space Intelligence Center Holds Program About Empowering Women in the...

  3. Real-space formulation of the electrostatic potential and total...

    Office of Scientific and Technical Information (OSTI)

    direct evaluation in real space. Unlike conventional reciprocal space formulations, no Fourier transforms or reciprocal lattice summations are required, and the formulation is well...

  4. Klamath Churches (5) Space Heating Low Temperature Geothermal...

    Open Energy Info (EERE)

    Churches (5) Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Klamath Churches (5) Space Heating Low Temperature Geothermal Facility Facility...

  5. Solar Power Beaming: From Space to Earth

    SciTech Connect (OSTI)

    Rubenchik, A M; Parker, J M; Beach, R J; Yamamoto, R M

    2009-04-14

    Harvesting solar energy in space and power beaming the collected energy to a receiver station on Earth is a very attractive way to help solve mankind's current energy and environmental problems. However, the colossal and expensive 'first step' required in achieving this goal has to-date stifled its initiation. In this paper, we will demonstrate that recent advance advances in laser and optical technology now make it possible to deploy a space-based system capable of delivering 1 MW of energy to a terrestrial receiver station, via a single unmanned commercial launch into Low Earth Orbit (LEO). Figure 1 depicts the overall concept of our solar power beaming system, showing a large solar collector in space, beaming a coherent laser beam to a receiving station on Earth. We will describe all major subsystems and provide technical and economic discussion to support our conclusions.

  6. Cubature on Wiener Space: Pathwise Convergence

    SciTech Connect (OSTI)

    Bayer, Christian Friz, Peter K.

    2013-04-15

    Cubature on Wiener space (Lyons and Victoir in Proc. R. Soc. Lond. A 460(2041):169-198, 2004) provides a powerful alternative to Monte Carlo simulation for the integration of certain functionals on Wiener space. More specifically, and in the language of mathematical finance, cubature allows for fast computation of European option prices in generic diffusion models.We give a random walk interpretation of cubature and similar (e.g. the Ninomiya-Victoir) weak approximation schemes. By using rough path analysis, we are able to establish weak convergence for general path-dependent option prices.

  7. THE KILOPARSEC-SCALE STAR FORMATION LAW AT REDSHIFT 4: WIDESPREAD, HIGHLY EFFICIENT STAR FORMATION IN THE DUST-OBSCURED STARBURST GALAXY GN20

    SciTech Connect (OSTI)

    Hodge, J. A.; Riechers, D.; Decarli, R.; Walter, F.; Carilli, C. L.; Daddi, E.

    2015-01-01

    We present high-resolution observations of the 880?m (rest-frame FIR) continuum emission in the z=4.05 submillimeter galaxy GN20 from the IRAM Plateau de Bure Interferometer (PdBI). These data resolve the obscured star formation (SF) in this unlensed galaxy on scales of 0.''3נ0.''2 (?2.1נ1.3kpc). The observations reveal a bright (16 1mJy) dusty starburst centered on the cold molecular gas reservoir and showing a bar-like extension along the major axis. The striking anti-correlation with the Hubble Space Telescope/Wide Field Camera 3 imaging suggests that the copious dust surrounding the starburst heavily obscures the rest-frame UV/optical emission. A comparison with 1.2mm PdBI continuum data reveals no evidence for variations in the dust properties across the source within the uncertainties, consistent with extended SF, and the peak star formation rate surface density (119 8 M {sub ?} yr{sup 1}kpc{sup 2}) implies that the SF in GN20 remains sub-Eddington on scales down to 3kpc{sup 2}. We find that the SF efficiency (SFE) is highest in the central regions of GN20, leading to a resolved SF law with a power-law slope of ?{sub SFR}??{sub H{sub 2}{sup 2.11.0}}, and that GN20 lies above the sequence of normal star-forming disks, implying that the dispersion in the SF law is not due solely to morphology or choice of conversion factor. These data extend previous evidence for a fixed SFE per free-fall time to include the star-forming medium on ?kiloparsec scales in a galaxy 12Gyr ago.

  8. Automated Design Space Exploration with Aspen

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

    Spafford, Kyle L.; Vetter, Jeffrey S.

    2015-01-01

    Architects and applications scientists often use performance models to explore a multidimensional design space of architectural characteristics, algorithm designs, and application parameters. With traditional performance modeling tools, these explorations forced users to first develop a performance model and then repeatedly evaluate and analyze the model manually. These manual investigations proved laborious and error prone. More importantly, the complexity of this traditional process often forced users to simplify their investigations. To address this challenge of design space exploration, we extend our Aspen (Abstract Scalable Performance Engineering Notation) language with three new language constructs: user-defined resources, parameter ranges, and a collection ofmore » costs in the abstract machine model. Then, we use these constructs to enable automated design space exploration via a nonlinear optimization solver. We show how four interesting classes of design space exploration scenarios can be derived from Aspen models and formulated as pure nonlinear programs. The analysis tools are demonstrated using examples based on Aspen models for a three-dimensional Fast Fourier Transform, the CoMD molecular dynamics proxy application, and the DARPA Streaming Sensor Challenge Problem. Our results show that this approach can compose and solve arbitrary performance modeling questions quickly and rigorously when compared to the traditional manual approach.« less

  9. Space Exploration and the Benefits to Mankind

    SciTech Connect (OSTI)

    Moser, T.L.; Freitag, R.; Schneider, W.C.

    1990-10-01

    Paper presented at the 41st Congress of the International Astronautical Federation in Dresden, GDR in October 1990. This paper analyzes the past challenges of the space program's multi-national cooperative agreements and examines the challenges of the future as we quickly become a global society. Cross Reference ESD-T1.

  10. Checkpoint-Restart in User Space

    Energy Science and Technology Software Center (OSTI)

    2013-07-19

    CRUISE implements a user-space file system that stores data in main memory and transparently spills over to other storage, like local flash memory or the parallel file system, as needed. CRUISE also exposes file contents fo remote direct memory access, allowing external tools to copy files to the parallel file system in the background with reduced CPU interruption.

  11. Building America Webinar: Retrofitting Central Space Conditioning

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

    Strategies for Multifamily Buildings - Steam Systems, Retrofit Measure Packages, Hydronic Systems | Department of Energy Steam Systems, Retrofit Measure Packages, Hydronic Systems Building America Webinar: Retrofitting Central Space Conditioning Strategies for Multifamily Buildings - Steam Systems, Retrofit Measure Packages, Hydronic Systems This presentation is included in the July 16, 2014, and provides information about best practices, costs, and savings associated with optimizing steam

  12. Testimony Before the House Committee on Science, Space, and Technology

    Broader source: Energy.gov [DOE]

    Secretary Moniz's full written testimony prepared for the House Committee on Science, Space, and Technology.

  13. Full Service Leased Space Data Report | Department of Energy

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

    Full Service Leased Space Data Report Full Service Leased Space Data Report The Full Service Leased Space Data Report is to be used for voluntary reporting of scope 3 emissions from fully serviced leased space where the agency does not purchase energy directly. File fullservice_spacedatareport.xlsx

  14. ADMINISTRATIVE RECORDS SCHEDULE 11: SPACE AND MAINTENANCE RECORDS |

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

    Department of Energy 1: SPACE AND MAINTENANCE RECORDS ADMINISTRATIVE RECORDS SCHEDULE 11: SPACE AND MAINTENANCE RECORDS This schedule provides for the disposal of all copies, wherever located in the Department of records relating to space and maintenance, except as indicated below. PDF icon ADMINISTRATIVE RECORDS SCHEDULE 11: SPACE AND MAINTENANCE RECORDS More Documents & Publications ADMINISTRATIVE RECORDS SCHEDULE 11: SPACE AND MAINTENANCE RECORDS ADMINISTRATIVE RECORDS SCHEDULE 12:

  15. Gauge fields and ghosts in Rindler space

    SciTech Connect (OSTI)

    Zhitnitsky, Ariel R.

    2010-11-15

    We consider a two-dimensional Maxwell system defined on the Rindler space with metric ds{sup 2}=exp(2a{xi}){center_dot}(d{eta}{sup 2}-d{xi}{sup 2}) with the goal to study the dynamics of the ghosts. We find an extra contribution to the vacuum energy in comparison with Minkowski space-time with metric ds{sup 2}=dt{sup 2}-dx{sup 2}. This extra contribution can be traced to the unphysical degrees of freedom (in Minkowski space). The technical reason for this effect to occur is the property of Bogolubov's coefficients which mix the positive- and negative-frequency modes. The corresponding mixture cannot be avoided because the projections to positive-frequency modes with respect to Minkowski time t and positive-frequency modes with respect to the Rindler observer's proper time {eta} are not equivalent. The exact cancellation of unphysical degrees of freedom which is maintained in Minkowski space cannot hold in the Rindler space. In the Becchi-Rouet-Stora-Tyutin (BRST) approach this effect manifests itself as the presence of BRST charge density in L and R parts. An inertial observer in Minkowski vacuum |0> observes a universe with no net BRST charge only as a result of cancellation between the two. However, the Rindler observers who do not ever have access to the entire space-time would see a net BRST charge. In this respect the effect resembles the Unruh effect. The effect is infrared (IR) in nature, and sensitive to the horizon and/or boundaries. We interpret the extra energy as the formation of the ''ghost condensate'' when the ghost degrees of freedom cannot propagate, but nevertheless do contribute to the vacuum energy. Exact computations in this simple two-dimensional model support the claim made in a previous paper [F. R. Urban and A. R. Zhitnitsky, Nucl. Phys. B835, 135 (2010).] that the ghost contribution might be responsible for the observed dark energy in a four-dimensional Friedmann-Lemaitre-Robertson-Walker universe.

  16. COLLOQUIUM: Space Physics and the Role of Magnetic Reconnection in Space

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

    Weather | Princeton Plasma Physics Lab June 11, 2014, 4:00pm to 5:30pm Colloquia MBG Auditorium COLLOQUIUM: Space Physics and the Role of Magnetic Reconnection in Space Weather Professor Vassilis Angelopoulous UCLA Earth's magnetosphere is buffeted by the solar wind. The interaction transfers energy electro-mechanically into Earth's environment and sets the magnetospheric and ionospheric plasma into motion. The energy is ultimately converted to heat raising the scale-height of the

  17. Initial tests of thermoacoustic space power engine.

    SciTech Connect (OSTI)

    Backhaus, S. N.

    2002-01-01

    Future NASA deep-space missions will require radioisotope-powered electric generators that are just as reliable as current RTGs, but more efficient and of higher specific power (Wikg). Thennoacoustic engines at the -1-kW scale have converted high-temperature heat into acoustic, or PV, power without moving parts at 30% efficiency. Consisting of only tubes and a few heat exchangers, thennoacoustic engines are low mass and promise to be highly reliable. Coupling a thennoacoustic engine to a low mass, highly reliable and efficient linear alternator will create a heat-driven electric generator suitable for deep-space applications. Conversion efficiency data will be presented on a demonstration thennoacoustic engine designed for the 1 00-Watt power range.

  18. Thermoacoustic power systems for space applications

    SciTech Connect (OSTI)

    Backhaus, S. N.; Tward, E.; Pedach, M.

    2001-01-01

    Future NASA deep-space missions will require radioisotope-powered electric generators that are just as reliable as current RTGs, but more efficient and of higher specific power (W/kg). Thermoacoustic engines can convert high-temperature heat into acoustic, or PV, power without moving parts at 30% efficiency. Consisting of only tubes and a few heat exchangers, these engines are low mass and promise to be highly reliable. Coupling a thermoacoustic engine to a low-mass, highly reliable and efficient linear alternator will create a heat-driven electric generator suitable for deep-space applications. Data will be presented on the first tests of a demonstration thermoacoustic engine designed for the 100-Watt power range.

  19. Momentum-space Argonne V18 interaction

    SciTech Connect (OSTI)

    Veerasamy, S.; Polyzou, W. N.

    2011-09-15

    This paper gives a momentum-space representation of the Argonne V18 potential as an expansion in products of spin-isospin operators with scalar coefficient functions of the momentum transfer. Two representations of the scalar coefficient functions for the strong part of the interaction are given. One is as an expansion in an orthonormal basis of rational functions and the other as an expansion in Chebyshev polynomials on different intervals. Both provide practical and efficient representations for computing the momentum-space potential that do not require integration or interpolation. Programs based on both expansions are available as supplementary material. Analytic expressions are given for the scalar coefficient functions of the Fourier transform of the electromagnetic part of the Argonne V18. A simple method for computing the partial-wave projections of these interactions from the operator expressions is also given.

  20. Applications for space power by laser transmission

    SciTech Connect (OSTI)

    Landis, G.A.

    1994-12-31

    A new method for providing power to space consists of using high-power CW lasers on the ground to beam power to photovoltaic receivers in space. Such large lasers could be located at cloud-free sites at one or more ground locations, and use large mirrors with adaptive optical correction to reduce the beam spread due to diffraction or atmospheric turbulence. This can result in lower requirements for battery storage, due to continuous illumination of arrays even during periods of shadow by the Earth, and higher power output, due to the higher efficiency of photovoltaic arrays under laser illumination compared to solar and the ability to achieve higher intensities of illumination. Applications include providing power for satellites during eclipse, providing power to resurrect satellites which are failing due to solar array degradation, powering orbital transfer vehicles or lunar transfer shuttles, and providing night power to a solar array on the moon.

  1. Exploring theory space with Monte Carlo reweighting

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

    Gainer, James S.; Lykken, Joseph; Matchev, Konstantin T.; Mrenna, Stephen; Park, Myeonghun

    2014-10-13

    Theories of new physics often involve a large number of unknown parameters which need to be scanned. Additionally, a putative signal in a particular channel may be due to a variety of distinct models of new physics. This makes experimental attempts to constrain the parameter space of motivated new physics models with a high degree of generality quite challenging. We describe how the reweighting of events may allow this challenge to be met, as fully simulated Monte Carlo samples generated for arbitrary benchmark models can be effectively re-used. Specifically, we suggest procedures that allow more efficient collaboration between theorists andmore » experimentalists in exploring large theory parameter spaces in a rigorous way at the LHC.« less

  2. Exploring theory space with Monte Carlo reweighting

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

    Gainer, James S.; Lykken, Joseph; Matchev, Konstantin T.; Mrenna, Stephen; Park, Myeonghun

    2014-10-13

    Theories of new physics often involve a large number of unknown parameters which need to be scanned. Additionally, a putative signal in a particular channel may be due to a variety of distinct models of new physics. This makes experimental attempts to constrain the parameter space of motivated new physics models with a high degree of generality quite challenging. We describe how the reweighting of events may allow this challenge to be met, as fully simulated Monte Carlo samples generated for arbitrary benchmark models can be effectively re-used. In particular, we suggest procedures that allow more efficient collaboration between theoristsmoreand experimentalists in exploring large theory parameter spaces in a rigorous way at the LHC.less

  3. Exploring theory space with Monte Carlo reweighting

    SciTech Connect (OSTI)

    Gainer, James S.; Lykken, Joseph; Matchev, Konstantin T.; Mrenna, Stephen; Park, Myeonghun

    2014-10-13

    Theories of new physics often involve a large number of unknown parameters which need to be scanned. Additionally, a putative signal in a particular channel may be due to a variety of distinct models of new physics. This makes experimental attempts to constrain the parameter space of motivated new physics models with a high degree of generality quite challenging. We describe how the reweighting of events may allow this challenge to be met, as fully simulated Monte Carlo samples generated for arbitrary benchmark models can be effectively re-used. Specifically, we suggest procedures that allow more efficient collaboration between theorists and experimentalists in exploring large theory parameter spaces in a rigorous way at the LHC.

  4. Space Electronics and Signal Processing (ISR-4)

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

    4 Space Electronics and Signal Processing Developing custom sensors, instruments, and systems for applications requiring advanced detection, monitoring, or assessment technologies Contacts Group Leader Roberta Klisiewicz Email Deputy Group Leader Myles Fitzgerald Email Staff Operations Manager Tanner Trujillo Email Administrative Specialist Amy Shade Email Prometheus LANL Prometheus program developed and launched eight advanced 1.5U cubesats in November 2013. Quality, reliable instruments for

  5. Particle accelerator employing transient space charge potentials

    DOE Patents [OSTI]

    Post, Richard F. (Walnut Creek, CA)

    1990-01-01

    The invention provides an accelerator for ions and charged particles. The plasma is generated and confined in a magnetic mirror field. The electrons of the plasma are heated to high temperatures. A series of local coils are placed along the axis of the magnetic mirror field. As an ion or particle beam is directed along the axis in sequence the coils are rapidly pulsed creating a space charge to accelerate and focus the beam of ions or charged particles.

  6. Center for Space and Earth Science

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

    Call for Proposals Submit Proposals Research Subject Areas Types of Proposals Funding for Projects Evaluation and Selection Acceptance and Rejection Events, Deadlines Partnerships NSEC » CSES Center for Space and Earth Science Formerly known as the Institute for Geophysics, Planetary Physics, and Signatures (IGPPS) Contact Director Reiner Friedel (505) 665-1936 Email Professional Staff Assistant Georgia D. Sanchez (505) 665-0855 Email Science Discipline Leaders Astrophysics & Cosmology Hui

  7. Space Conditioning Standing Technical Committee Strategic Plan

    Energy Savers [EERE]

    Space Conditioning Standing Technical Committee Strategic Plan, v2011a Revised: January 2012 Committee Chair: 2011 Eric Martin Janet McIlvaine BA-PIRC Standing Technical Committee Strategic Plan Overview Standing Technical Committees (STCs) focus on resolving key technical action items required to meet Building America performance goals. STC chairs lead each committees' activities in addressing specific research challenges, gaps in understanding, and new research opportunities. Committees

  8. #SpaceWeek: Science of the Cosmos | Department of Energy

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

    of the Cosmos #SpaceWeek: Science of the Cosmos June 16, 2015 - 10:57am Addthis #SpaceWeek: Science of the Cosmos Pat Adams Pat Adams Digital Content Specialist, Office of Public Affairs How can I participate? Missed the "Energy of Star Wars" Google+ Hangout? You can watch the whole event here. And take a look at all of our other #SpaceWeek content. #SpaceWeek: Science of the Cosmos During #SpaceWeek we covered the Department of Energy's space expertise, from nuclear-powered spacecraft

  9. Delayed star formation in isolated dwarf galaxies: Hubble space telescope star formation history of the Aquarius dwarf irregular

    SciTech Connect (OSTI)

    Cole, Andrew A.; Weisz, Daniel R.; Dolphin, Andrew E.; Skillman, Evan D.; McConnachie, Alan W.; Brooks, Alyson M.; Leaman, Ryan E-mail: drw@ucsc.edu E-mail: skillman@astro.umn.edu E-mail: abrooks@physics.rutgers.edu

    2014-11-01

    We have obtained deep images of the highly isolated (d = 1 Mpc) Aquarius dwarf irregular galaxy (DDO 210) with the Hubble Space Telescope Advanced Camera for Surveys. The resulting color-magnitude diagram (CMD) reaches more than a magnitude below the oldest main-sequence turnoff, allowing us to derive the star formation history (SFH) over the entire lifetime of the galaxy with a timing precision of ?10% of the lookback time. Using a maximum likelihood fit to the CMD we find that only ?10% of all star formation in Aquarius took place more than 10 Gyr ago (lookback time equivalent to redshift z ? 2). The star formation rate increased dramatically ?6-8 Gyr ago (z ? 0.7-1.1) and then declined until the present time. The only known galaxy with a more extreme confirmed delay in star formation is Leo A, a galaxy of similar M {sub H} {sub I}/M {sub *}, dynamical mass, mean metallicity, and degree of isolation. The delayed stellar mass growth in these galaxies does not track the mean dark matter accretion rate from CDM simulations. The similarities between Leo A and Aquarius suggest that if gas is not removed from dwarf galaxies by interactions or feedback, it can linger for several gigayears without cooling in sufficient quantity to form stars efficiently. We discuss possible causes for the delay in star formation including suppression by reionization and late-time mergers. We find reasonable agreement between our measured SFHs and select cosmological simulations of isolated dwarfs. Because star formation and merger processes are both stochastic in nature, delayed star formation in various degrees is predicted to be a characteristic (but not a universal) feature of isolated small galaxies.

  10. BARRELING THROUGH THE VACUUM OF SPACE at

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

    1663 October 2015 1663 October 2015 19 BARRELING THROUGH THE VACUUM OF SPACE at over 17,000 miles per hour, Earth's reflection glinting off its solar panels, the satellite is fiercely efficient and mission driven. It has hard edges and cold surfaces. It is brand new and state-of-the-art. It is an engineering masterpiece. And it's roughly the size of an electric pencil sharpener. Satellites are generally thought of as hulking beasts of instrumentation. They are billion-dollar machines capable of

  11. Space nuclear power, propulsion, and related technologies.

    SciTech Connect (OSTI)

    Berman, Marshall

    1992-01-01

    Sandia National Laboratories (Sandia) is one of the nation's largest research and development (R&D) facilities, with headquarters at Albuquerque, New Mexico; a laboratory at Livermore, California; and a test range near Tonopah, Nevada. Smaller testing facilities are also operated at other locations. Established in 1945, Sandia was operated by the University of California until 1949, when, at the request of President Truman, Sandia Corporation was formed as a subsidiary of Bell Lab's Western Electric Company to operate Sandia as a service to the U.S. Government without profit or fee. Sandia is currently operated for the U.S. Department of Energy (DOE) by AT&T Technologies, Inc., a wholly-owned subsidiary of AT&T. Sandia's responsibility is national security programs in defense and energy with primary emphasis on nuclear weapon research and development (R&D). However, Sandia also supports a wide variety of projects ranging from basic materials research to the design of specialized parachutes. Assets, owned by DOE and valued at more than $1.2 billion, include about 600 major buildings containing about 372,000 square meters (m2) (4 million square feet [ft2]) of floor space, located on land totalling approximately 1460 square kilometers (km2) (562 square miles [mi]). Sandia employs about 8500 people, the majority in Albuquerque, with about 1000 in Livermore. Approximately 60% of Sandia's employees are in technical and scientific positions, and the remainder are in crafts, skilled labor, and administrative positions. As a multiprogram national laboratory, Sandia has much to offer both industrial and government customers in pursuing space nuclear technologies. The purpose of this brochure is to provide the reader with a brief summary of Sandia's technical capabilities, test facilities, and example programs that relate to military and civilian objectives in space. Sandia is interested in forming partnerships with industry and government organizations, and has already formed several cooperative alliances and agreements. Because of the synergism of multiple governmental and industrial sponsors of many programs, Sandia is frequently able to provide complex technical solutions in a relatively short time, and often at lower cost to a particular customer. They have listed a few ongoing programs at Sandia related to space nuclear technology as examples of the possible synergisms that could result from forming teams and partnerships with related technologies and objectives.

  12. Space Nuclear Program INL's role in energizing exploration

    SciTech Connect (OSTI)

    Idaho National Laboratory

    2008-04-22

    Idaho National Laboratory is helping make space exploration possible with the development of radioisotope power systems, which can work in areas too harsh and too isolated in space where the suns rays cannot be used for energy.

  13. Working Group Report on - Space Nuclear Power Systems and Nuclear...

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

    Working Group Report on - Space Nuclear Power Systems and Nuclear Waste Technology R&D Working Group Report on - Space Nuclear Power Systems and Nuclear Waste Technology R&D "Even ...

  14. Space-Age Ceramics Get Their Toughest Test

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

    Space-Age Ceramics Get Their Toughest Test Space-Age Ceramics Get Their Toughest Test Print Wednesday, 17 April 2013 07:23 Advanced ceramic composites can withstand the ultrahigh...

  15. Azur Space Solar Power GmbH | Open Energy Information

    Open Energy Info (EERE)

    Space Solar Power GmbH Jump to: navigation, search Name: Azur Space Solar Power GmbH Place: Heilbronn, Baden-Wrttemberg, Germany Zip: 74072 Product: German manufacturer of...

  16. Space-Age Ceramics Get Their Toughest Test

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

    Space-Age Ceramics Get Their Toughest Test Space-Age Ceramics Get Their Toughest Test Print Tuesday, 11 December 2012 14:54 Advanced ceramic composites can withstand the ultrahigh...

  17. Solaren Space Solar Power Plant | Open Energy Information

    Open Energy Info (EERE)

    Space Solar Power Plant Facility Solaren Space Solar Sector Solar Facility Type Photovoltaic Developer Solaren Corp Generating Capacity (MW) 200.0200 MW 200,000 kW 200,000,000...

  18. Space Nuclear Program INL's role in energizing exploration

    ScienceCinema (OSTI)

    Idaho National Laboratory

    2010-01-08

    Idaho National Laboratory is helping make space exploration possible with the development of radioisotope power systems, which can work in areas too harsh and too isolated in space where the suns rays cannot be used for energy.

  19. Talk explores Laboratory's 50 years of space research

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

    Talk explores Laboratory's 50 years of space research Talk explores Laboratory's 50 years of space research The talk, titled "Los Alamos National Laboratory's 50 Years in Space," will highlight the Laboratory's significant discoveries and events in the field. October 3, 2013 Laboratory fellow and astrophysicist Ed Fenimore, and Laboratory planetary scientist and principal investigator of the ChemCam team Roger Wiens, will talk about Los Alamos National Laboratory's 50 years of space

  20. Emittance and Phase Space Exchange for Advanced Beam Manipulation and

    Office of Scientific and Technical Information (OSTI)

    Diagnostics (Journal Article) | SciTech Connect Phase Space Exchange for Advanced Beam Manipulation and Diagnostics Citation Details In-Document Search Title: Emittance and Phase Space Exchange for Advanced Beam Manipulation and Diagnostics Alternative chicane-type beam lines are proposed for exact emittance exchange between transverse phase space (x,x') and longitudinal phase space (z,{delta}), where x is the transverse position, x' is the transverse divergence, and z and {delta} are

  1. Wiesbaden Motel & Health Resort Space Heating Low Temperature...

    Open Energy Info (EERE)

    Heating Low Temperature Geothermal Facility Facility Wiesbaden Motel & Health Resort Sector Geothermal energy Type Space Heating Location Ouray, Colorado Coordinates...

  2. CRAD, Confined Spaces Assessment Plan | Department of Energy

    Office of Environmental Management (EM)

    Confined Spaces Assessment Plan CRAD, Confined Spaces Assessment Plan Performance Objective: This assessment provides a basis for evaluating the safety effectiveness of the contractor's confined or enclosed spaces procedure, and for establishing compliance with DOE and OSHA requirements. Specifically, this assessment is to verify the information and findings of the BN Management Self Assessment Report on "Confined Space", ES&H-MSA-03-13, dated December 31, 2003. Criteria: Practices

  3. Building America Webinar: High Performance Space Conditioning Systems, Part

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

    II - Design Options for Locating Ducts within Conditioned Space | Department of Energy II - Design Options for Locating Ducts within Conditioned Space Building America Webinar: High Performance Space Conditioning Systems, Part II - Design Options for Locating Ducts within Conditioned Space William Zoeller, Consortium for Advanced Residential Retrofit (CARB) delivers this presentation, which provides an overview of the technical aspects of buried and encapsulated duct systems as well as the

  4. Space Conditioning Standing Technical Commitee Presentation | Department of

    Energy Savers [EERE]

    Energy Space Conditioning Standing Technical Commitee Presentation Space Conditioning Standing Technical Commitee Presentation This presentation outlines the goals of the Space Conditioning Standing Technical ommittee, as presented at the Building America Spring 2012 Stakeholder meeting on February 29, 2012, in Austin, Texas. PDF icon space_conditioning_stc.pdf More Documents & Publications Standing Technical Committee Working Sessions Analysis Methods and Tools Standing Technical

  5. Before the House Science, Space, and Technology Committee | Department of

    Energy Savers [EERE]

    Energy Science, Space, and Technology Committee Before the House Science, Space, and Technology Committee Before the House Science, Space, and Technology Committee By: Dr. Arun Majumdar, Director Advanced Research Projects Agency (ARPA-E) Subject: DOE's Clean Energy R&D Activities PDF icon 6-15-11_Final_Testimony_Majumdar.pdf More Documents & Publications Before the House Subcommittee on Investigations and Oversight Committee on Science, Space and Technology Overview on Energy

  6. NASA Marshall Space Flight Center Improves Cooling System Performance |

    Office of Environmental Management (EM)

    Department of Energy Marshall Space Flight Center Improves Cooling System Performance NASA Marshall Space Flight Center Improves Cooling System Performance NASA Marshall Space Flight Center Improves Cooling System Performance Case study details Marshall Space Flight Center's innovative technologies to improve water efficiency and cooling performance for one of its problematic cooling systems. The program saved the facility more than 800,000 gallons of water in eight months. PDF icon

  7. Transactions of the fifth symposium on space nuclear power systems

    SciTech Connect (OSTI)

    El-Genk, M.S.; Hoover, M.D.

    1988-01-01

    This paper contains the presented papers at the fourth symposium on space nuclear power systems. Topics of these paper include: space nuclear missions and applications, reactors and shielding, nuclear electric and nuclear propulsion, high-temperature materials, instrumentation and control, energy conversion and storage, space nuclear fuels, thermal management, nuclear safety, simulation and modeling, and multimegawatt system concepts. (LSP)

  8. Transactions of the fourth symposium on space nuclear power systems

    SciTech Connect (OSTI)

    El-Genk, M.S.; Hoover, M.D.

    1987-01-01

    This paper contains the presented papers at the fourth symposium on space nuclear power systems. Topics of these papers include: space nuclear missions and applications, reactors and shielding, nuclear electric and nuclear propulsion, refractory alloys and high-temperature materials, instrumentation and control, energy conversion and storage, space nuclear fuels, thermal management, nuclear safety, simulation and modeling, and multimegawatt system concepts. (LSP)

  9. Phase-space localization: Topological aspects of quantum chaos

    SciTech Connect (OSTI)

    Leboeuf, P. (Division de Physique Theorique, Institut de Physique Nucleire, 91406 Orsay CEDEX (France)); Kurchan, J. (Nuclear Physics Department, Weizmann Institute of Science, Rehovot 76100 (Israel)); Feingold, M. (Lawrence Berkeley Laboratory, University of California, Berkeley, CA (USA) Department of Physics, University of California, Berkeley, CA (USA)); Arovas, D.P. (Department of Physics, B-019, University of California at San Diego, La Jolla, CA (USA))

    1990-12-17

    We study quantized classically chaotic maps on a toroidal two-diensional phase space. A discrete, topological criterion for phase-space localization is presented. To each eigenfunction an integer is associated, analogous to a quantized Hall conductivity, which when nonzero reflects phase-space delocalization. A model system is studied, and a correspondence between delocalization and chaotic classical dynamics is discussed.

  10. Global-Address Space Networking (GASNet) Library

    Energy Science and Technology Software Center (OSTI)

    2011-04-06

    GASNet (Global-Address Space Networking) is a language-independent, low-level networking layer that provides network-independent, high-performance communication primitives tailored for implementing parallel global address space SPMD languages such as UPC and Titanium. The interface is primarily intended as a compilation target and for use by runtime library writers (as opposed to end users), and the primary goals are high performance, interface portability, and expressiveness. GASNet is designed specifically to support high-performance, portable implementations of global address spacemore » languages on modern high-end communication networks. The interface provides the flexibility and extensibility required to express a wide variety of communication patterns without sacrificing performance by imposing large computational overheads in the interface. The design of the GASNet interface is partitioned into two layers to maximize porting ease without sacrificing performance: the lower level is a narrow but very general interface called the GASNet core API - the design is basedheavily on Active Messages, and is implemented directly on top of each individual network architecture. The upper level is a wider and more expressive interface called GASNet extended API, which provides high-level operations such as remote memory access and various collective operations. This release implements GASNet over MPI, the Quadrics "elan" API, the Myrinet "GM" API and the "LAPI" interface to the IBM SP switch. A template is provided for adding support for additional network interfaces.« less

  11. A DEEP HUBBLE SPACE TELESCOPE SEARCH FOR ESCAPING LYMAN CONTINUUM FLUX AT z {approx} 1.3: EVIDENCE FOR AN EVOLVING IONIZING EMISSIVITY

    SciTech Connect (OSTI)

    Siana, Brian; Bridge, Carrie R.; Teplitz, Harry I.; Chary, Ranga-Ram; Colbert, James W.; Scarlata, Claudia; Ferguson, Henry C.; Brown, Thomas M.; Giavalisco, Mauro; Dickinson, Mark; De Mello, Duilia F.; Conselice, Christopher J.; Gardner, Jonathan P.

    2010-11-01

    We have obtained deep Hubble Space Telescope far-UV images of 15 starburst galaxies at z {approx} 1.3 in the GOODS fields to search for escaping Lyman continuum (LyC) photons. These are the deepest far-UV images (m{sub AB} = 28.7, 3{sigma}, 1'' diameter) over this large an area (4.83 arcmin{sup 2}) and provide some of the best escape fraction constraints for any galaxies at any redshift. We do not detect any individual galaxies, with 3{sigma} limits to the LyC ({approx}700 A) flux 50-149 times fainter (in f{sub {nu}}) than the rest-frame UV (1500 A) continuum fluxes. Correcting for the mean intergalactic medium (IGM) attenuation (factor {approx}2), as well as an intrinsic stellar Lyman break (factor {approx}3), these limits translate to relative escape fraction limits of f{sub esc,rel} < [0.03, 0.21]. The stacked limit is f{sub esc,rel}(3{sigma}) < 0.02. We use a Monte Carlo simulation to properly account for the expected distribution of line-of-sight IGM opacities. When including constraints from previous surveys at z {approx} 1.3 we find that, at the 95% confidence level, no more than 8% of star-forming galaxies at z {approx} 1.3 can have relative escape fractions greater than 0.50. Alternatively, if the majority of galaxies have low, but non-zero, escaping LyC, the escape fraction cannot be more than 0.04. In light of some evidence for strong LyC emission from UV-faint regions of Lyman break galaxies (LBGs) at z {approx} 3, we also stack sub-regions of our galaxies with different surface brightnesses and detect no significant LyC flux at the f{sub esc,rel} < 0.03 level. Both the stacked limits and the limits from the Monte Carlo simulation suggest that the average ionizing emissivity (relative to non-ionizing UV emissivity) at z {approx} 1.3 is significantly lower than has been observed in LBGs at z {approx} 3. If the ionizing emissivity of star-forming galaxies is in fact increasing with redshift, it would help to explain the high photoionization rates seen in the IGM at z>4 and reionization of the IGM at z>6.

  12. Marginally trapped submanifolds in Lorentzian space forms and in the Lorentzian product of a space form by the real line

    SciTech Connect (OSTI)

    Anciaux, Henri; Godoy, Yamile

    2015-02-15

    We give local, explicit representation formulas for n-dimensional spacelike submanifolds which are marginally trapped in the Minkowski space ?{sub 1}{sup n+2}, the de Sitter space dS{sup n+2}, the anti-de Sitter space AdS{sup n+2} and the Lorentzian products S{sup n+1} ? and ?{sup n+1} ? of the sphere and the hyperbolic space by the real line.

  13. Emittance and Phase Space Exchange (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Emittance and Phase Space Exchange Citation Details In-Document Search Title: Emittance and Phase Space Exchange Alternative chicane-type beam lines are proposed for exact emittance exchange between horizontal phase space (x; x{prime}) and longitudinal phase space (z; {delta}). Methods to achieve exact phase space exchanges, i.e. mapping x to z, x{prime} to {delta}, z to x and {delta} to x{prime} are suggested. Methods to mitigate the thick-lens effect of the transverse cavity on emittance

  14. Solar terrestrial coupling through space plasma processes

    SciTech Connect (OSTI)

    Birn, J.

    2000-12-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project investigates plasma processes that govern the interaction between the solar wind, charged particles ejected from the sun, and the earth's magnetosphere, the region above the ionosphere governed by the terrestrial magnetic field. Primary regions of interest are the regions where different plasma populations interact with each other. These are regions of particularly dynamic plasma behavior, associated with magnetic flux and energy transfer and dynamic energy release. The investigations concerned charged particle transport and energization, and microscopic and macroscopic instabilities in the magnetosphere and adjacent regions. The approaches combined space data analysis with theory and computer simulations.

  15. Small space object imaging : LDRD final report.

    SciTech Connect (OSTI)

    Ackermann, Mark R.; Valley, Michael T.; Kearney, Sean Patrick

    2009-10-01

    We report the results of an LDRD effort to investigate new technologies for the identification of small-sized (mm to cm) debris in low-earth orbit. This small-yet-energetic debris presents a threat to the integrity of space-assets worldwide and represents significant security challenge to the international community. We present a nonexhaustive review of recent US and Russian efforts to meet the challenges of debris identification and removal and then provide a detailed description of joint US-Russian plans for sensitive, laser-based imaging of small debris at distances of hundreds of kilometers and relative velocities of several kilometers per second. Plans for the upcoming experimental testing of these imaging schemes are presented and a preliminary path toward system integration is identified.

  16. Heatpipe space power and propulsion systems

    SciTech Connect (OSTI)

    Houts, M.G.; Poston, D.I.; Ranken, W.A.

    1995-12-01

    Safe, reliable, low-mass space power and propulsion systems could have numerous civilian and military applications. This paper discusses two fission-powered concepts: The Heatpipe Power System (HPS), which provides power only; and the Heatpipe Bimodal System (HBS), which provides both power and thermal propulsion. Both concepts have 10 important features. First, only existing technology and recently tested fuel forms are used. Second, fuel can be removed whenever desired, which greatly facilitates system fabrication and handling. Third, full electrically heated system testing of all modes is possible, with minimal operations required to replace the heaters with fuel and to ready the system for launch. Fourth, the systems are passively subcritical during launch accidents. Fifth, a modular approach is used, and most technical issues can be resolved with inexpensive module tests. Sixth, bonds between dissimilar metals are minimized. Seventh, there are no single-point failures during power mode operation. Eighth, the fuel burnup rate is quite low to help ensure >10-yr system life. Ninth, there are no pumped coolant loops, and the systems can be shut down and restarted without coolant freeze/thaw concerns. Finally, full ground nuclear test is not needed, and development costs will be low. One design for a low-power HPS uses SNAP-10A-style thermoelectric power converters to produce 5 kWe at a system mass of {approximately}500 kg. The unicouple thermoelectric converters have a hot-shoe temperature of 1275 K and reject waste heat at 775 K. This type of thermoelectric converter has been used extensively by the space program and has demonstrated an operational lifetime of decades. A core with a larger number of smaller modules (same overall size) can be used to provide up to 500 kWt to a power conversion subsystem, and a slightly larger core using a higher heatpipe to fuel ratio can provide >1 MWt.

  17. Distortion effects in Trojan Horse applications

    SciTech Connect (OSTI)

    Pizzone, R. G.; La Cognata, M.; Lamia, L.; Mukhamedzhanov, A. M.; Blokhintsev, L. D.; Irgaziev, B.; Bertulani, C. A.; Spitaleri, C.

    2012-11-20

    Deuteron induced quasi-free scattering and reactions have been extensively investigated in the past few decades. This was done not only for nuclear structure and processes study but also for the important astrophysical implication (Trojan Horse Method, THM). In particular the width of the neutron momentum distribution in deuteron will be studied as a function of the transferred momentum. The same will be done for other nuclides of possible use as Trojan Horse particles. Trojan horse method applications will also be discussed because the momentum distribution of the spectator particle inside the Trojan horse nucleus is a necessary input for this method. The impact of the width (FWHM) variation on the extraction of the astrophysical S(E)-factor is discussed.

  18. SPECIAL COLLOQUIUM : Building a Commercial Space Launch System and the Role of Space Tourism in the Future (exceptionally on Tuesday)

    ScienceCinema (OSTI)

    None

    2011-04-25

    The talk will explore a little of the history of space launch systems and rocketry, will explain why commercial space tourism did not take off after Apollo, and what is happening right now with commercial space systems such as Virgin's, utilising advances in aerospace technology not exploited by conventional ground-based rocket systems. I will then explain the Virgin Galactic technology, its business plan as a US-regulated space tourism company, and the nature of its applications. I will then go on to say a little of how our system can be utilised for sub-orbital space science based on a commercial business plan

  19. COMPOSITION OF LOW-REDSHIFT HALO GAS

    SciTech Connect (OSTI)

    Cen Renyue

    2013-06-20

    Halo gas in low-z (z < 0.5) {>=}0.1 L{sub *} galaxies in high-resolution, large-scale cosmological hydrodynamic simulations is examined with respect to three components: cold, warm, and hot with temperatures of <10{sup 5}, 10{sup 5-6}, and >10{sup 6} K, respectively. Utilizing O VI {lambda}{lambda}1032, 1038 absorption lines, the warm component is compared to observations, and agreement is found with respect to the galaxy-O VI line correlation, the ratio of the O VI line incidence rate in blue to red galaxies, and the amount of O VI mass in star-forming galaxies. A detailed account of the sources of warm halo gas (stellar feedback heating, gravitational shock heating, and accretion from the intergalactic medium), inflowing and outflowing warm halo gas metallicity disparities, and their dependencies on galaxy types and environment is also presented. With the warm component securely anchored, our simulations make the following additional predictions. First, cold gas is the primary component in inner regions with its mass comprising 50% of all gas within galactocentric radius r = (30, 150) kpc in (red, blue) galaxies. Second, at r > (30, 200) kpc in (red, blue) galaxies the hot component becomes the majority. Third, the warm component is a perpetual minority, with its contribution peaking at {approx}30% at r = 100-300 kpc in blue galaxies and never exceeding 5% in red galaxies. The significant amount of cold gas in low-z early-type galaxies, which was found in simulations and in agreement with recent observations (Thom et al.), is intriguing, as is the dominance of hot gas at large radii in blue galaxies.

  20. THE M31 VELOCITY VECTOR. I. HUBBLE SPACE TELESCOPE PROPER-MOTION MEASUREMENTS

    SciTech Connect (OSTI)

    Sohn, Sangmo Tony; Anderson, Jay; Van der Marel, Roeland P.

    2012-07-01

    We present the first proper-motion (PM) measurements for the galaxy M31. We obtained new V-band imaging data with the Hubble Space Telescope ACS/WFC and the WFC3/UVIS instruments of three fields: a spheroid field near the minor axis, an outer disk field along the major axis, and a field on the Giant Southern Stream. The data provide five to seven year time baselines with respect to pre-existing deep first-epoch observations of the same fields. We measure the positions of thousands of M31 stars and hundreds of compact background galaxies in each field. High accuracy and robustness is achieved by building and fitting a unique template for each individual object. The average PM for each field is obtained from the average motion of the M31 stars between the epochs with respect to the background galaxies. For the three fields, the observed PMs ({mu}{sub W}, {mu}{sub N}) are, in units of mas yr{sup -1}, (- 0.0458, -0.0376) {+-} (0.0165, 0.0154), (- 0.0533, -0.0104) {+-} (0.0246, 0.0244), and (- 0.0179, -0.0357) {+-} (0.0278, 0.0272), respectively. The ability to average over large numbers of objects and over the three fields yields a final displacement accuracy of a few thousandths of a pixel, corresponding to only 12 {mu}as yr{sup -1}. This is comparable to what has been achieved for other Local Group galaxies using Very Long Baseline Array observations of water masers. Potential systematic errors are controlled by an analysis strategy that corrects for detector charge transfer inefficiency, spatially and time-dependent geometric distortion, and point-spread function variations. The robustness of the PM measurements and uncertainties are supported by the fact that data from different instruments, taken at different times and with different telescope orientations, as well as measurements of different fields, all yield statistically consistent results. Papers II and III of this series explore the implications of the new measurements for our understanding of the history, future, and mass of the Local Group.

  1. The Configuration Space Toolkit (C-Space Toolkit or CSTK) Ver. 2.5 beta

    Energy Science and Technology Software Center (OSTI)

    2010-02-24

    The C-Space Toolkit provides a software library that makes it easier to program motion planning, simulation, robotics, and virtual reality codes using the Configuration Space abstraction. Key functionality (1) enables the user to special create representations of movable and stationary rigid geometric objects, and (2) perform fast distance, interference (clash) detection, collision detection, closest-feature pairs, and contact queries in terms of object configuration. Not only can queries be computed at any given point in configurationmore » space, but they can be done exactly over linear-translational path segments and approximately for rotational path segments. Interference detection and distance computations can be done with respect to the Minkowski sum of the original geometry and a piece of convex geometry. The Toolkit takes as raw model input (1) collections of convex polygons that form the boundaries of models and (2) convex polyhedra, cones, cylinders, and discs that are models and model components. Configurations are given in terms of homogeneous transforms. A simple OpenGL-based system for displaying and animating the geometric objects is included in the implementation. This version, 2.5 Beta, incorporates feature additions and enhancements, improvements in algorithms, improved robustness, bug fixes and cleaned-up source code, better compliance with standards and recent programming convention, changes to the build process for the software, support for more recent hardware and software platforms, and improvements to documentation and source-code comments.« less

  2. Two-dimensional relativistic space charge limited current flow in the drift space

    SciTech Connect (OSTI)

    Liu, Y. L.; Chen, S. H.; Koh, W. S.; Ang, L. K.

    2014-04-15

    Relativistic two-dimensional (2D) electrostatic (ES) formulations have been derived for studying the steady-state space charge limited (SCL) current flow of a finite width W in a drift space with a gap distance D. The theoretical analyses show that the 2D SCL current density in terms of the 1D SCL current density monotonically increases with D/W, and the theory recovers the 1D classical Child-Langmuir law in the drift space under the approximation of uniform charge density in the transverse direction. A 2D static model has also been constructed to study the dynamical behaviors of the current flow with current density exceeding the SCL current density, and the static theory for evaluating the transmitted current fraction and minimum potential position have been verified by using 2D ES particle-in-cell simulation. The results show the 2D SCL current density is mainly determined by the geometrical effects, but the dynamical behaviors of the current flow are mainly determined by the relativistic effect at the current density exceeding the SCL current density.

  3. Connecting the physical and psychosocial space to Sandia's mission.

    SciTech Connect (OSTI)

    Emmanuel, Glory Ruth; Silva, Austin Ray

    2014-07-01

    Sandia Labs has corporate, lab-wide efforts to enhance the research environment as well as improve physical space. However, these two efforts are usually done in isolation. The integration of physical space design with the nurturing of what we call psychosocial space can foster more efficient and effective creativity, innovation, collaboration, and performance. This paper presents a brief literature review on how academia and industry are studying the integration of physical and psychosocial space and focuses on the efforts that we, the authors, have made to improve the research environment in the Cyber Engineering Research Lab (CERL), home to Group 1460. Interviews with subject matter experts from Silicon Valley and the University of New Mexico plus changes to actual spaces in CERL provided us with six lessons learned when integrating physical and psychosocial space. We describe these six key takeaways in hopes that Sandia will see this area as an evolving research capability that Sandia can both contribute to and benefit from.

  4. Testing coupled dark energy with large scale structure observation

    SciTech Connect (OSTI)

    Yang, Weiqiang; Xu, Lixin, E-mail: d11102004@mail.dlut.edu.cn, E-mail: lxxu@dlut.edu.cn [Institute of Theoretical Physics, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian, 116024 (China)

    2014-08-01

    The coupling between the dark components provides a new approach to mitigate the coincidence problem of cosmological standard model. In this paper, dark energy is treated as a fluid with a constant equation of state, whose coupling with dark matter is Q-bar =3H?{sub x}?-bar {sub x}. In the frame of dark energy, we derive the evolution equations for the density and velocity perturbations. According to the Markov Chain Monte Carlo method, we constrain the model by currently available cosmic observations which include cosmic microwave background radiation, baryon acoustic oscillation, type Ia supernovae, and f?{sub 8}(z) data points from redshift-space distortion. The results show the interaction rate in ? regions: ?{sub x}=0.00328{sub -0.00328-0.00328-0.00328}{sup +0.000736+0.00549+0.00816}, which means that the recently cosmic observations favor a small interaction rate which is up to the order of 10{sup -2}, meanwhile, the measurement of redshift-space distortion could rule out the large interaction rate in the ? region.

  5. Heat pump system with selective space cooling

    DOE Patents [OSTI]

    Pendergrass, Joseph C. (Gainesville, GA)

    1997-01-01

    A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve.

  6. Heat pump system with selective space cooling

    DOE Patents [OSTI]

    Pendergrass, J.C.

    1997-05-13

    A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve. 4 figs.

  7. Wedge assembly for electrical transformer component spacing

    DOE Patents [OSTI]

    Baggett, Franklin E. (Paducah, KY); Cage, W. Franklin (LaCenter, KY)

    1991-01-01

    A wedge assembly that is easily inserted between two surfaces to be supported thereby, and thereafter expanded to produce a selected spacing between those surfaces. This wedge assembly has two outer members that are substantially identical except that they are mirror images of each other. Oppositely directed faces of these of these outer members are substantially parallel for the purpose of contacting the surfaces to be separated. The outer faces of these outer members that are directed toward each other are tapered so as to contact a center member having complementary tapers on both faces. A washer member is provided to contact a common end of the outer members, and a bolt member penetrates this washer and is threadably received in a receptor of the center member. As the bolt member is threaded into the center member, the center member is drawn further into the gap between the outer members and thereby separates these outer members to contact the surfaces to be separated. In the preferred embodiment, the contacting surfaces of the outer member and the center member are provided with guide elements. The wedge assembly is described for use in separating the secondary windings from the laminations of an electrical power transformer.

  8. Space Dust Analysis Could Provide Clues to Solar System Origins

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

    Space Dust Analysis Could Provide Clues to Solar System Origins Print New studies of space dust captured by NASA's Stardust Interstellar Dust Collector have shown that interstellar particles may be much more complex in structure and composition than previously thought. -The tiny particles could give scientists chemical clues about the origins of our solar system. Amateur Enthusiasts Key to Research Progress The space dust that was captured by NASA's Stardust Interstellar Dust Collector landed in

  9. Space Dust Analysis Could Provide Clues to Solar System Origins

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

    Space Dust Analysis Could Provide Clues to Solar System Origins Print New studies of space dust captured by NASA's Stardust Interstellar Dust Collector have shown that interstellar particles may be much more complex in structure and composition than previously thought. -The tiny particles could give scientists chemical clues about the origins of our solar system. Amateur Enthusiasts Key to Research Progress The space dust that was captured by NASA's Stardust Interstellar Dust Collector landed in

  10. Space Dust Analysis Could Provide Clues to Solar System Origins

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

    Space Dust Analysis Could Provide Clues to Solar System Origins Print New studies of space dust captured by NASA's Stardust Interstellar Dust Collector have shown that interstellar particles may be much more complex in structure and composition than previously thought. -The tiny particles could give scientists chemical clues about the origins of our solar system. Amateur Enthusiasts Key to Research Progress The space dust that was captured by NASA's Stardust Interstellar Dust Collector landed in

  11. Space Dust Analysis Could Provide Clues to Solar System Origins

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

    Space Dust Analysis Could Provide Clues to Solar System Origins Print New studies of space dust captured by NASA's Stardust Interstellar Dust Collector have shown that interstellar particles may be much more complex in structure and composition than previously thought. -The tiny particles could give scientists chemical clues about the origins of our solar system. Amateur Enthusiasts Key to Research Progress The space dust that was captured by NASA's Stardust Interstellar Dust Collector landed in

  12. Space Dust Analysis Could Provide Clues to Solar System Origins

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

    Space Dust Analysis Could Provide Clues to Solar System Origins Space Dust Analysis Could Provide Clues to Solar System Origins Print Thursday, 18 September 2014 12:34 New studies of space dust captured by NASA's Stardust Interstellar Dust Collector have shown that interstellar particles may be much more complex in structure and composition than previously thought. -The tiny particles could give scientists chemical clues about the origins of our solar system. Amateur Enthusiasts Key to Research

  13. Space-Age Ceramics Get Their Toughest Test

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

    Space-Age Ceramics Get Their Toughest Test Space-Age Ceramics Get Their Toughest Test Print Wednesday, 17 April 2013 07:23 Advanced ceramic composites can withstand the ultrahigh operational temperatures projected for hypersonic jet and next-generation gas-turbine engines, but real-time analysis of the mechanical properties of these space-age materials at ultrahigh temperatures has been a challenge-until now. Researchers have developed the first testing facility that enables microtomography of

  14. Space Dust Analysis Could Provide Clues to Solar System Origins

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

    Space Dust Analysis Could Provide Clues to Solar System Origins Print New studies of space dust captured by NASA's Stardust Interstellar Dust Collector have shown that interstellar particles may be much more complex in structure and composition than previously thought. -The tiny particles could give scientists chemical clues about the origins of our solar system. Amateur Enthusiasts Key to Research Progress The space dust that was captured by NASA's Stardust Interstellar Dust Collector landed in

  15. Space Dust Analysis Could Provide Clues to Solar System Origins

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

    Space Dust Analysis Could Provide Clues to Solar System Origins Print New studies of space dust captured by NASA's Stardust Interstellar Dust Collector have shown that interstellar particles may be much more complex in structure and composition than previously thought. -The tiny particles could give scientists chemical clues about the origins of our solar system. Amateur Enthusiasts Key to Research Progress The space dust that was captured by NASA's Stardust Interstellar Dust Collector landed in

  16. Space-Age Ceramics Get Their Toughest Test

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

    Space-Age Ceramics Get Their Toughest Test Space-Age Ceramics Get Their Toughest Test Print Tuesday, 11 December 2012 14:54 Advanced ceramic composites can withstand the ultrahigh operational temperatures projected for hypersonic jet and next generation gas turbine engines, but real-time analysis of the mechanical properties of these space-age materials at ultrahigh temperatures has been a challenge - until now. Berkeley Lab and UC Berkeley researchers have developed the first testing facility

  17. Passive Solar Building Design and Solar Thermal Space Heating Webinar |

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

    Department of Energy Passive Solar Building Design and Solar Thermal Space Heating Webinar Passive Solar Building Design and Solar Thermal Space Heating Webinar Watch a recording of National Renewable Energy Laboratory (NREL) Senior Engineer Andy Walker's Nov. 30, 2010, presentation about passive solar building design, and solar thermal space heating technologies and applications. It's one in a series of Webinars to support state and local projects funded by Sustainable Energy Resources for

  18. Photo of the Week: Supercomputing... from Space | Department of Energy

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

    Supercomputing... from Space Photo of the Week: Supercomputing... from Space June 27, 2013 - 1:46pm Addthis The Cibola Flight Experiment (CFE) is an experimental small satellite that was designed to prove that off-the-shelf computer processors can be used for supercomputing in space. The processors, also called field-programmable gate arrays, can be reconfigured while the satellite is in orbit, enabling researchers to modify them for a variety of tasks like studying lightning, disturbances in

  19. Disk Space Quota Management | Argonne Leadership Computing Facility

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

    Account Information Accounts and Access FAQ Connect & Log In Using CRYPTOCards Disk Space Quota Management Allocations Mira/Cetus/Vesta Cooley Policies Documentation Feedback Please provide feedback to help guide us as we continue to build documentation for our new computing resource. [Feedback Form] Disk Space Quota Management As you manage your project's disk space quota, it's important to remember that users you approve as to be added as project members are also added to the project's

  20. 2016 SHIELDS Workshop: Shielding Society from Space Weather

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

    April » 2016 SHIELDS Workshop 2016 SHIELDS Workshop: Shielding Society from Space Weather WHEN: Apr 04, 2016 8:00 AM - Apr 08, 2016 5:00 PM WHERE: Drury Plaza Hotel, Santa Fe, NM CONTACT: Gian Luca Delzanno (505) 667-2604 CATEGORY: Science TYPE: Workshop INTERNAL: Calendar Login Event Description Space weather is an emerging research area within space science that is rapidly gaining importance and public recognition because of its technological and societal impact. A recent report from the