Showing papers by "Eli S. Rykoff published in 2016"
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TL;DR: In this paper, the authors proposed a framework for the integration of the INSU-IN2P3-INP project with the National Science and Technology Facilities Council (NSF) and the Higher Education Funding Council for England (HEFL).
Abstract: ESA; CNES (France); CNRS/INSU-IN2P3-INP (France); ASI (Italy); CNR (Italy); INAF (Italy); NASA (USA); DoE (USA); STFC (UK); UKSA (UK); CSIC (Spain); MINECO (Spain); JA (Spain); RES (Spain); Tekes (Finland); AoF (Finland); CSC (Finland); DLR (Germany); MPG (Germany); CSA (Canada); DTU Space (Denmark); SER/SSO (Switzerland); RCN (Norway); SFI (Ireland); FCT/MCTES (Portugal); ERC (EU); PRACE (EU); Higher Education Funding Council for England; Science and Technology Facilities Council; Alfred P. Sloan Foundation; National Science Foundation; US Department of Energy Office of Science
1,178 citations
Posted Content•
TL;DR: DESI as discussed by the authors is a ground-based dark energy experiment that will study baryon acoustic oscillations (BAO) and the growth of structure through redshift-space distortions with a wide-area galaxy and quasar redshift survey.
Abstract: DESI (Dark Energy Spectroscopic Instrument) is a Stage IV ground-based dark energy experiment that will study baryon acoustic oscillations (BAO) and the growth of structure through redshift-space distortions with a wide-area galaxy and quasar redshift survey. To trace the underlying dark matter distribution, spectroscopic targets will be selected in four classes from imaging data. We will measure luminous red galaxies up to $z=1.0$. To probe the Universe out to even higher redshift, DESI will target bright [O II] emission line galaxies up to $z=1.7$. Quasars will be targeted both as direct tracers of the underlying dark matter distribution and, at higher redshifts ($ 2.1 < z < 3.5$), for the Ly-$\alpha$ forest absorption features in their spectra, which will be used to trace the distribution of neutral hydrogen. When moonlight prevents efficient observations of the faint targets of the baseline survey, DESI will conduct a magnitude-limited Bright Galaxy Survey comprising approximately 10 million galaxies with a median $z\approx 0.2$. In total, more than 30 million galaxy and quasar redshifts will be obtained to measure the BAO feature and determine the matter power spectrum, including redshift space distortions.
965 citations
TL;DR: In this paper, the authors presented the results of the Dark Energy Survey (DES) 2013, 2014, 2015, 2016, 2017, 2018, 2019 and 2019 at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign.
Abstract: US Department of Energy; US National Science Foundation; Ministry of Science and Education of Spain; Science and Technology Facilities Council of the United Kingdom; Higher Education Funding Council for England; National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign; Kavli Institute of Cosmological Physics at the University of Chicago; Center for Cosmology and Astro-Particle Physics at the Ohio State University; Mitchell Institute for Fundamental Physics and Astronomy at Texas AM University; Financiadora de Estudos e Projetos; Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico and the Ministerio da Ciencia; Tecnologia e Inovacao; Deutsche Forschungsgemeinschaft; Collaborating Institutions in the Dark Energy Survey; National Science Foundation [AST-1138766]; University of California at Santa Cruz; University of Cambridge, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas-Madrid; University of Chicago, University College London; DES-Brazil Consortium; University of Edinburgh; Eidgenossische Technische Hochschule (ETH) Zurich, Fermi National Accelerator Laboratory; University of Illinois at Urbana-Champaign; Institut de Ciencies de l'Espai (IEEC/CSIC); Institut de Fisica d'Altes Energies, Lawrence Berkeley National Laboratory; Ludwig-Maximilians Universitat Munchen; European Research Council [FP7/291329]; MINECO [AYA2012-39559, ESP2013-48274, FPA2013-47986]; Centro de Excelencia Severo Ochoa [SEV-2012-0234]; European Research Council under the European Union [240672, 291329, 306478]
789 citations
TL;DR: In this article, the sky localization of the first observed compact binary merger is presented, where the authors describe the low-latency analysis of the LIGO data and present a sky localization map.
Abstract: A gravitational-wave (GW) transient was identified in data recorded by the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) detectors on 2015 September 14. The event, initially designated G184098 and later given the name GW150914, is described in detail elsewhere. By prior arrangement, preliminary estimates of the time, significance, and sky location of the event were shared with 63 teams of observers covering radio, optical, near-infrared, X-ray, and gamma-ray wavelengths with ground- and space-based facilities. In this Letter we describe the low-latency analysis of the GW data and present the sky localization of the first observed compact binary merger. We summarize the follow-up observations reported by 25 teams via private Gamma-ray Coordinates Network circulars, giving an overview of the participating facilities, the GW sky localization coverage, the timeline, and depth of the observations. As this event turned out to be a binary black hole merger, there is little expectation of a detectable electromagnetic (EM) signature. Nevertheless, this first broadband campaign to search for a counterpart of an Advanced LIGO source represents a milestone and highlights the broad capabilities of the transient astronomy community and the observing strategies that have been developed to pursue neutron star binary merger events. Detailed investigations of the EM data and results of the EM follow-up campaign are being disseminated in papers by the individual teams.
288 citations
DSM1, University of Bonn2, Centre national de la recherche scientifique3, University of Nice Sophia Antipolis4, Istanbul University5, University of Zagreb6, University of Bristol7, University of Bologna8, University of Western Australia9, Max Planck Society10, Paris Diderot University11, University of Geneva12, European Southern Observatory13, University of Birmingham14, Ludwig Maximilian University of Munich15, University of Oxford16, University of Paris17, University of Michigan18, University of Liège19, Aryabhatta Research Institute of Observational Sciences20, Durham University21, University of KwaZulu-Natal22, Université Paris-Saclay23, Chalmers University of Technology24, INAF25, University of Victoria26, Liverpool John Moores University27, Australian Astronomical Observatory28, University of Chicago29, Taras Shevchenko National University of Kyiv30, University of Illinois at Urbana–Champaign31, Aristotle University of Thessaloniki32, National Institute of Astrophysics, Optics and Electronics33, University of Copenhagen34, Presidency University, Kolkata35, Leiden University36, Stanford University37, Goddard Space Flight Center38, Princeton University39, University of California, Davis40
TL;DR: The XXL-XMM survey as discussed by the authors provides constraints on the dark energy equation of state from the space-time distribution of clusters of galaxies and serves as a pathfinder for future, wide-area X-ray missions.
Abstract: Context. The quest for the cosmological parameters that describe our universe continues to motivate the scientific community to undertake very large survey initiatives across the electromagnetic spectrum. Over the past two decades, the Chandra and XMM-Newton observatories have supported numerous studies of X-ray-selected clusters of galaxies, active galactic nuclei (AGNs), and the X-ray background. The present paper is the first in a series reporting results of the XXL-XMM survey; it comes at a time when the Planck mission results are being finalised. Aims. We present the XXL Survey, the largest XMM programme totaling some 6.9 Ms to date and involving an international consortium of roughly 100 members. The XXL Survey covers two extragalactic areas of 25 deg(2) each at a point-source sensitivity of similar to 5 x 10(-15) erg s(-1) cm(-2) in the [0.5-2] keV band (completeness limit). The survey's main goals are to provide constraints on the dark energy equation of state from the space-time distribution of clusters of galaxies and to serve as a pathfinder for future, wide-area X-ray missions. We review science objectives, including cluster studies, AGN evolution, and large-scale structure, that are being conducted with the support of approximately 30 follow-up programmes. Methods. We describe the 542 XMM observations along with the associated multi-lambda and numerical simulation programmes. We give a detailed account of the X-ray processing steps and describe innovative tools being developed for the cosmological analysis. Results. The paper provides a thorough evaluation of the X-ray data, including quality controls, photon statistics, exposure and background maps, and sky coverage. Source catalogue construction and multi-lambda associations are briefly described. This material will be the basis for the calculation of the cluster and AGN selection functions, critical elements of the cosmological and science analyses. Conclusions. The XXL multi-lambda data set will have a unique lasting legacy value for cosmological and extragalactic studies and will serve as a calibration resource for future dark energy studies with clusters and other X-ray selected sources. With the present article, we release the XMM XXL photon and smoothed images along with the corresponding exposure maps.
272 citations
Stanford University1, University of Arizona2, University of California, Santa Cruz3, University of Sussex4, Ludwig Maximilian University of Munich5, University of Portsmouth6, Rhodes University7, University College London8, Fermilab9, University of Paris10, University of Pennsylvania11, University of Illinois at Urbana–Champaign12, Australian National University13, Liverpool John Moores University14, University of Southampton15, University of Queensland16, Technische Universität München17, University of Michigan18, Swinburne University of Technology19, University of California, Berkeley20, Lawrence Berkeley National Laboratory21, University of KwaZulu-Natal22, Ohio State University23, University of Manchester24, Australian Astronomical Observatory25, University of Sydney26, University of São Paulo27, University of Edinburgh28, Texas A&M University29, Princeton University30, Max Planck Society31, California Institute of Technology32, University of Oxford33, Universidade Federal do Rio Grande do Sul34, University of Porto35, Argonne National Laboratory36
TL;DR: The redMaPPer algorithm as discussed by the authors was applied to 150 deg(2) of Science Verification (SV) data from the Dark Energy Survey (DES), and to the Sloan Digital Sky Survey (SDSS) DR8 photometric data set.
Abstract: We describe updates to the redMaPPer algorithm, a photometric red-sequence cluster finder specifically designed for large photometric surveys. The updated algorithm is applied to 150 deg(2) of Science Verification (SV) data from the Dark Energy Survey (DES), and to the Sloan Digital Sky Survey (SDSS) DR8 photometric data set. The DES SV catalog is locally volume limited and contains 786 clusters with richness lambda > 20 (roughly equivalent to M500c greater than or similar to 10(14) h(70)(-1)M(circle dot)) and 0.2 < z < 0.9. The DR8 catalog consists of 26,311 clusters with 0.08 < z < 0.6, with a sharply increasing richness threshold as a function of redshift for z greater than or similar to 0.35. The photometric redshift performance of both catalogs is shown to be excellent, with photometric redshift uncertainties controlled at the sigma(z)/(1+ z) similar to 0.01 level for z greater than or similar to 0.7, rising to similar to 0.02 at z similar to 0.9 in DES SV. We make use of Chandra and XMM X-ray and South Pole Telescope Sunyaev-Zeldovich data to show that the centering performance and mass-richness scatter are consistent with expectations based on prior runs of redMaPPer on SDSS data. We also show how the redMaPPer photo-z and richness estimates are relatively insensitive to imperfect star/galaxy separation and small-scale star masks.
258 citations
University of Pennsylvania1, Brookhaven National Laboratory2, University of Manchester3, ETH Zurich4, Princeton University5, Stanford University6, Autonomous University of Barcelona7, University of Michigan8, Ludwig Maximilian University of Munich9, Fermilab10, California Institute of Technology11, Max Planck Society12, University College London13, Ohio State University14, Argonne National Laboratory15, Rhodes University16, University of Paris17, University of Portsmouth18, University of Illinois at Urbana–Champaign19, Institut de Ciències de l'Espai20, Texas A&M University21, Australian Astronomical Observatory22, University of São Paulo23, University of Sussex24
TL;DR: In this paper, weak lensing shear catalogues for 139 square degrees of data taken during the Science Verification (SV) time for the new Dark Energy Camera (DECam) being used for the Dark Energy Survey (DES).
Abstract: We present weak lensing shear catalogues for 139 square degrees of data taken during the Science Verification (SV) time for the new Dark Energy Camera (DECam) being used for the Dark Energy Survey (DES). We describe our object selection, point spread function estimation and shear measurement procedures using two independent shear pipelines, IM3SHAPE and NGMIX, which produce catalogues of 2.12 million and 3.44 million galaxies respectively. We detail a set of null tests for the shear measurements and find that they pass the requirements for systematic errors at the level necessary for weak lensing science applications using the SV data. We also discuss some of the planned algorithmic improvements that will be necessary to produce sufficiently accurate shear catalogues for the full 5-year DES, which is expected to cover 5000 square degrees.
174 citations
Institute for the Physics and Mathematics of the Universe1, California Institute of Technology2, Princeton University3, Harvard University4, University of Chicago5, University of Illinois at Urbana–Champaign6, University of Tokyo7, Carnegie Mellon University8, University of Arizona9, Stanford University10
TL;DR: Alfred P. Sloan Foundation; National Science Foundation; U.S. Department of Energy; National Aeronautics and Space Administration; Japanese Monbukagakusho; Max Planck Society; Higher Education Funding Council for England; American Museum of Natural History; Astrophysical Institute Potsdam; University of Basel; Case Western Reserve University, University of Chicago; Drexel University; Fermilab; Institute for Advanced Study; Japan Participation Group; Johns Hopkins University; Joint Institute for Nuclear Astrophysics; Kavli Institute for Particle
Abstract: Alfred P. Sloan Foundation; National Science Foundation; U.S. Department of Energy; National Aeronautics and Space Administration; Japanese Monbukagakusho; Max Planck Society; Higher Education Funding Council for England; American Museum of Natural History; Astrophysical Institute Potsdam; University of Basel; University of Cambridge; Case Western Reserve University; University of Chicago; Drexel University; Fermilab; Institute for Advanced Study; Japan Participation Group; Johns Hopkins University; Joint Institute for Nuclear Astrophysics; Kavli Institute for Particle Astrophysics and Cosmology; Korean Scientist Group; Chinese Academy of Sciences (LAMOST); Los Alamos National Laboratory; Max-Planck-Institute for Astronomy (MPIA); Max-Planck-Institute for Astrophysics (MPA); New Mexico State University; Ohio State University; University of Pittsburgh; University of Portsmouth; Princeton University; United States Naval Observatory; University of Washington; Spanish MultiDark Consolider Project [CSD2009-00064]; World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan; FIRST program "Subaru Measurements of Images and Redshifts (SuMIRe)", CSTP, Japan; JSPS Promotion of Science [15K17600, 16H01089, 23340061, 26610058, 26800093]; MEXT [15H05893, 15K21733, 15H05892]; JSPS Program for Advancing Strategic International Networks to Accelerate the Circulation of Talented Researchers; Japan Society for the Promotion of Science (JSPS); Jet Propulsion Laboratory, California Institute of Technology; Kavli Institute for Cosmological Physics at the University of Chicago [PHY-1125897]; University of Tokyo-Princeton strategic partnership grant; Department of Energy Early Career Award program
173 citations
University of Arizona1, Stanford University2, Autonomous University of Barcelona3, University of Queensland4, Ludwig Maximilian University of Munich5, University College London6, University of Cambridge7, University of Pennsylvania8, University of Paris9, Fermilab10, University of Portsmouth11, University of Notre Dame12, University of Illinois at Urbana–Champaign13, Australian National University14, Texas A&M University15, California Institute of Technology16, University of Michigan17, Swinburne University of Technology18, Max Planck Society19, Ohio State University20, Lawrence Berkeley National Laboratory21, Australian Astronomical Observatory22, University of São Paulo23, University of Sussex24, Universidade Federal do Rio Grande do Sul25, Argonne National Laboratory26
TL;DR: RedMaGiC as mentioned in this paper is an automated algorithm for selecting luminous red galaxies (LRGs) by self-training the color cuts necessary to produce a luminosity-thresholded LRG sample of constant comoving density.
Abstract: We introduce redMaGiC, an automated algorithm for selecting luminous red galaxies (LRGs). The algorithm was specifically developed to minimize photometric redshift uncertainties in photometric large-scale structure studies. redMaGiC achieves this by self-training the colour cuts necessary to produce a luminosity-thresholded LRG sample of constant comoving density. We demonstrate that redMaGiC photo-zs are very nearly as accurate as the best machine learning-based methods, yet they require minimal spectroscopic training, do not suffer from extrapolation biases, and are very nearly Gaussian. We apply our algorithm to Dark Energy Survey (DES) Science Verification (SV) data to produce a redMaGiC catalogue sampling the redshift range z is an element of [0.2, 0.8]. Our fiducial sample has a comoving space density of 10(-3) (h(-1) Mpc)(-3), and a median photo-z bias (z(spec) - z(photo)) and scatter (sigma(z)/(1 + z)) of 0.005 and 0.017, respectively. The corresponding 5 sigma outlier fraction is 1.4 per cent. We also test our algorithm with Sloan Digital Sky Survey Data Release 8 and Stripe 82 data, and discuss how spectroscopic training can be used to control photo-z biases at the 0.1 per cent level.
172 citations
Stanford University1, University of Arizona2, University of California, Santa Cruz3, University of Sussex4, Ludwig Maximilian University of Munich5, University of Portsmouth6, University College London7, Rhodes University8, Fermilab9, University of Paris10, University of Pennsylvania11, University of Illinois at Urbana–Champaign12, Australian National University13, Liverpool John Moores University14, University of Southampton15, University of Queensland16, Technische Universität München17, University of Michigan18, Swinburne University of Technology19, University of California, Berkeley20, Lawrence Berkeley National Laboratory21, University of KwaZulu-Natal22, Ohio State University23, University of Manchester24, Australian Astronomical Observatory25, University of Sydney26, University of São Paulo27, University of Edinburgh28, Texas A&M University29, Princeton University30, Max Planck Society31, California Institute of Technology32, University of Oxford33, Universidade Federal do Rio Grande do Sul34, University of Porto35, Argonne National Laboratory36
TL;DR: In this paper, the authors describe updates to the Redmapper{} algorithm, a photometric red-sequence cluster finder specifically designed for large photometric surveys, applied to data from the Dark Energy Survey (DES), and to the Sloan Digital Sky Survey (SDSS) DR8 photometric data set.
Abstract: We describe updates to the \redmapper{} algorithm, a photometric red-sequence cluster finder specifically designed for large photometric surveys. The updated algorithm is applied to $150\,\mathrm{deg}^2$ of Science Verification (SV) data from the Dark Energy Survey (DES), and to the Sloan Digital Sky Survey (SDSS) DR8 photometric data set. The DES SV catalog is locally volume limited, and contains 786 clusters with richness $\lambda>20$ (roughly equivalent to $M_{\rm{500c}}\gtrsim10^{14}\,h_{70}^{-1}\,M_{\odot}$) and $0.2
156 citations
TL;DR: In this article, the authors present photometric redshift estimates for galaxies used in the weak lensing analysis of the DES SV data, and evaluate the performance of these methods against the matched spectroscopic catalogue.
Abstract: 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-Ufig simulations, SKYNET, and TPZ-are analyzed. For training, calibration, and testing of these methods, we construct a catalogue of spectroscopically confirmed galaxies matched against DES SV data. The performance of the methods is evaluated against the matched spectroscopic catalogue, focusing on metrics relevant for weak lensing analyses, with additional validation against COSMOS photo-z's. 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;1.00}. These bins each have systematic uncertainties delta z <= 0.05 in the mean of the fiducial SKYNET photo-z (dz). 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 sigma(8) of approximately 3%. This shift is within the one sigma statistical errors on sigma(8) for the DES SV shear catalogue. We further study the potential impact of systematic differences on the critical surface density, Sigma(crit), finding 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.
ETH Zurich1, University College London2, Max Planck Society3, University of Sussex4, Ludwig Maximilian University of Munich5, University of Pennsylvania6, IFAE7, Institute of Cosmology and Gravitation, University of Portsmouth8, Stanford University9, University of Manchester10, California Institute of Technology11, Ohio State University12, Princeton University13, Brookhaven National Laboratory14, Rhodes University15, Institut d'Astrophysique de Paris16, Carnegie Learning17, SLAC National Accelerator Laboratory18, National Center for Supercomputing Applications19, University of Illinois at Urbana–Champaign20, Institut de Ciències de l'Espai21, University of Southampton22, Fermilab23, University of Michigan24, University of Chicago25, Lawrence Berkeley National Laboratory26, University of California, Berkeley27, Australian Astronomical Observatory28, University of São Paulo29, Texas A&M University30, Catalan Institution for Research and Advanced Studies31, Complutense University of Madrid32, Argonne National Laboratory33
TL;DR: In this paper, a shear peak statistics analysis of the Dark Energy Survey (DES) Science Verification (SV) data, using weak gravitational lensing measurements from a 139 deg² field, was performed.
Abstract: Shear peak statistics has gained a lot of attention recently as a practical alternative to the two-point statistics for constraining cosmological parameters. We perform a shear peak statistics analysis of the Dark Energy Survey (DES) Science Verification (SV) data, using weak gravitational lensing measurements from a 139 deg² field. We measure the abundance of peaks identified in aperture mass maps, as a function of their signal-to-noise ratio, in the signal-to-noise range 0 4 would require significant corrections, which is why we do not include them in our analysis. We compare our results to the cosmological constraints from the two-point analysis on the SV field and find them to be in good agreement in both the central value and its uncertainty. We discuss prospects for future peak statistics analysis with upcoming DES data.
Posted Content•
TL;DR: DESI (Dark Energy Spectropic Instrument) as mentioned in this paper is a ground-based dark energy experiment that will study baryon acoustic oscillations and the growth of structure through redshift-space distortions with a wide-area galaxy and quasar redshift survey.
Abstract: DESI (Dark Energy Spectropic Instrument) is a Stage IV ground-based dark energy experiment that will study baryon acoustic oscillations and the growth of structure through redshift-space distortions with a wide-area galaxy and quasar redshift survey. The DESI instrument is a robotically-actuated, fiber-fed spectrograph capable of taking up to 5,000 simultaneous spectra over a wavelength range from 360 nm to 980 nm. The fibers feed ten three-arm spectrographs with resolution $R= \lambda/\Delta\lambda$ between 2000 and 5500, depending on wavelength. The DESI instrument will be used to conduct a five-year survey designed to cover 14,000 deg$^2$. This powerful instrument will be installed at prime focus on the 4-m Mayall telescope in Kitt Peak, Arizona, along with a new optical corrector, which will provide a three-degree diameter field of view. The DESI collaboration will also deliver a spectroscopic pipeline and data management system to reduce and archive all data for eventual public use.
TL;DR: Significant evidence of halo assembly bias for SDSS redMaPPer galaxy clusters in the redshift range is presented, which could bring a significant impact on both galaxy evolution and precision cosmology.
Abstract: We present significant evidence of halo assembly bias for SDSS redMaPPer galaxy clusters in the redshift range [0.1, 0.33]. By dividing the 8,648 clusters into two subsamples based on the average member galaxy separation from the cluster center, we first show that the two subsamples havevery similar halo mass of M200m ≃ 1.9 × 10 14 h −1 M⊙ based on the weak lensing signals at small radii R ≲ 10 h −1 Mpc. However, their halo bias inferred from both the large-scale weak lensing and the projected autocorrelation functions differs by a factor of ∼1.5, which is a signature of assembly bias. The same bias hypothesis for the two subsamples is excluded at 2.5σ in the weak lensing and 4.4σ in the autocorrelation data, respectively. This result could bring a significant impact on both galaxy evolution and precision cosmology.
Ludwig Maximilian University of Munich1, University of Cambridge2, Institut de Ciències de l'Espai3, University of Chicago4, McGill University5, University College London6, Fermilab7, University of Pennsylvania8, University of Michigan9, Stanford University10, University of Melbourne11, University of Illinois at Urbana–Champaign12, Max Planck Society13, Argonne National Laboratory14, Rhodes University15, Princeton University16, Carnegie Institution for Science17, Institut d'Astrophysique de Paris18, National Center for Supercomputing Applications19, Texas A&M University20, California Institute of Technology21, Autonomous University of Barcelona22, University of California, Berkeley23, Ohio State University24, Australian Astronomical Observatory25, University of São Paulo26, University of Sussex27, Case Western Reserve University28, University of Manchester29
TL;DR: In this paper, the authors measured the cross-correlation between the galaxy density in the DES Science Verification data and the lensing of the cosmic microwave background (CMB) as reconstructed with the Planck satellite and the South Pole Telescope (SPT), and found the data are fit by a model in which the amplitude of structure in the z < 1.2 universe is 0.73 ± 0.16 times as large as predicted in the Lambda cold dark matter Planck cosmology, a 1.7sigma deviation.
Abstract: We measure the cross-correlation between the galaxy density in the Dark Energy Survey (DES) Science Verification data and the lensing of the cosmic microwave background (CMB) as reconstructed with the Planck satellite and the South Pole Telescope (SPT). When using the DES main galaxy sample over the full redshift range 0.2 2sigma) detections in all bins. Comparing to the fiducial Planck cosmology, we find the redshift evolution of the signal matches expectations, although the amplitude is consistently lower than predicted across redshift bins. We test for possible systematics that could affect our result and find no evidence for significant contamination. Finally, we demonstrate how these measurements can be used to constrain the growth of structure across cosmic time. We find the data are fit by a model in which the amplitude of structure in the z< 1.2 universe is 0.73 ± 0.16 times as large as predicted in the Lambda cold dark matter Planck cosmology, a 1.7sigma deviation.
University of Cambridge1, Argonne National Laboratory2, University of Chicago3, Stanford University4, SLAC National Accelerator Laboratory5, Fermilab6, McGill University7, University of Pennsylvania8, University of Arizona9, Ludwig Maximilian University of Munich10, Max Planck Society11, University College London12, Rhodes University13, Princeton University14, Institut d'Astrophysique de Paris15, National Center for Supercomputing Applications16, University of Illinois at Urbana–Champaign17, Institut de Ciències de l'Espai18, University of California, Berkeley19, University of Michigan20, Ohio State University21, Australian Astronomical Observatory22, University of São Paulo23, Texas A&M University24, Massachusetts Institute of Technology25, IFAE26, Catalan Institution for Research and Advanced Studies27, California Institute of Technology28, University of Melbourne29, University of Sussex30, University of KwaZulu-Natal31, Complutense University of Madrid32, Brookhaven National Laboratory33, Harvard University34
TL;DR: The Isaac Newton Studentship at the University of Cambridge as mentioned in this paper has been used for the development of a supercomputing application at the National Center for Supercomputing Applications (NCS-1138766, PLR-1248097).
Abstract: Isaac Newton Studentship at the University of Cambridge; Science and Technologies Facilities Council (STFC); Kavli Foundation; STFC [ST/L000636/1]; Australian Research Council [DP150103208]; US Department of Energy; US National Science Foundation; Ministry of Science and Education of Spain; Science and Technology Facilities Council of the United Kingdom; Higher Education Funding Council for England; National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign; Kavli Institute of Cosmological Physics at the University of Chicago; Center for Cosmology and Astro-Particle Physics at the Ohio State University; Mitchell Institute for Fundamental Physics and Astronomy at Texas AM University; Financiadora de Estudos e Projetos; Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico; Ministerio da Ciencia, Tecnologia e Inovacao; Deutsche Forschungsgemeinschaft; National Science Foundation [AST-1138766, PLR-1248097]; Argonne National Laboratory; University of California at Santa Cruz; University of Cambridge; Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas-Madrid; University of Chicago; University College London; DES-Brazil Consortium; University of Edinburgh; Eidgenossische Technische Hochschule (ETH) Zurich; Fermi National Accelerator Laboratory; University of Illinois at Urbana-Champaign; Institut de Ciencies de l'Espai (IEEC/CSIC); Institut de Fisica d'Altes Energies; Lawrence Berkeley National Laboratory; Ludwig-Maximilians Universitat Munchen; associated Excellence Cluster Universe; University of Michigan; National Optical Astronomy Observatory; University of Nottingham; Ohio State University; University of Pennsylvania; University of Portsmouth; SLAC National Accelerator Laboratory; Stanford University; University of Sussex; Texas AM University; MINECO [AYA2012-39559, ESP2013-48274, FPA2013-47986]; Centro de Excelencia Severo Ochoa [SEV-2012-0234]; European Research Council under the European Union including ERC [240672, 291329, 306478]; NSF Physics Frontier Center [PHY-0114422]; Gordon and Betty Moore Foundation [947]; US Department of Energy [DE-AC02-06CH11357]; DOE/SC [DE-AC02-06CH11357]
Stanford University1, University of Manchester2, California Institute of Technology3, University of Pennsylvania4, Max Planck Society5, ETH Zurich6, University of Portsmouth7, Autonomous University of Barcelona8, University of Chicago9, Fermilab10, University of Michigan11, University College London12, Korea Astronomy and Space Science Institute13, Ohio State University14, Brookhaven National Laboratory15, Rhodes University16, Princeton University17, University of Cambridge18, Pierre-and-Marie-Curie University19, Centre national de la recherche scientifique20, University of Illinois at Urbana–Champaign21, Texas A&M University22, Ludwig Maximilian University of Munich23, Australian Astronomical Observatory24, University of São Paulo25, University of Sussex26, Argonne National Laboratory27
TL;DR: In this paper, the authors present measurements of weak gravitational lensing cosmic shear two-point statistics using Dark Energy Survey Science Verification data and demonstrate that their results are robust to the choice of shear measurement pipeline, either ngmix or im3shape.
Abstract: We present measurements of weak gravitational lensing cosmic shear two-point statistics using Dark Energy Survey Science Verification data. We demonstrate that our results are robust to the choice of shear measurement pipeline, either ngmix or im3shape, and robust to the choice of two-point statistic, including both real and Fourier-space statistics. Our results pass a suite of null tests including tests for B-mode contamination and direct tests for any dependence of the two-point functions on a set of 16 observing conditions and galaxy properties, such as seeing, airmass, galaxy color, galaxy magnitude, etc. We furthermore use a large suite of simulations to compute the covariance matrix of the cosmic shear measurements and assign statistical significance to our null tests. We find that our covariance matrix is consistent with the halo model prediction, indicating that it has the appropriate level of halo sample variance. We compare the same jackknife procedure applied to the data and the simulations in order to search for additional sources of noise not captured by the simulations. We find no statistically significant extra sources of noise in the data. The overall detection significance with tomography for our highest source density catalog is 9.7 sigma . Cosmological constraints from the measurements in this work are presented in a companion paper [DES et al., Phys. Rev. D 94, 022001 (2016).].
University of Southampton1, Institut de Ciències de l'Espai2, European University Cyprus3, University of Melbourne4, Texas A&M University5, Swinburne University of Technology6, University of Queensland7, Fermilab8, University of Illinois System9, Weizmann Institute of Science10, Lawrence Berkeley National Laboratory11, University of Chile12, Argonne National Laboratory13, University of California, Santa Barbara14, University of Chicago15, Australian Astronomical Observatory16, University of Pennsylvania17, Queen's University Belfast18, University College London19, National Center for Supercomputing Applications20, Stanford University21, Ludwig Maximilian University of Munich22, University of Michigan23, Max Planck Society24, Ohio State University25, Catalan Institution for Research and Advanced Studies26, Jet Propulsion Laboratory27, SLAC National Accelerator Laboratory28, University of Sussex29
TL;DR: In this article, a new hydrogen-poor superluminous supernova (SLSN-I) discovered by the Dark Energy Survey (DES) supernova program, with additional photometric data provided by the Survey Using DECam (DECam) for Super-Luminous Supernovae.
Abstract: We present DES14X3taz, a new hydrogen-poor superluminous supernova (SLSN-I) discovered by the Dark Energy Survey (DES) supernova program, with additional photometric data provided by the Survey Using DECam for Superluminous Supernovae. Spectra obtained using Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy on the Gran Telescopio CANARIAS show DES14X3taz is an SLSN-I at z = 0.608. Multi-color photometry reveals a double-peaked light curve: a blue and relatively bright initial peak that fades rapidly prior to the slower rise of the main light curve. Our multi-color photometry allows us, for the first time, to show that the initial peak cools from 22,000 to 8000 K over 15 rest-frame days, and is faster and brighter than any published core-collapse supernova, reaching 30% of the bolometric luminosity of the main peak. No physical 56Ni-powered model can fit this initial peak. We show that a shock-cooling model followed by a magnetar driving the second phase of the light curve can adequately explain the entire light curve of DES14X3taz. Models involving the shock-cooling of extended circumstellar material at a distance of sime400 ${\text{}}{R}_{\odot }$ are preferred over the cooling of shock-heated surface layers of a stellar envelope. We compare DES14X3taz to the few double-peaked SLSN-I events in the literature. Although the rise times and characteristics of these initial peaks differ, there exists the tantalizing possibility that they can be explained by one physical interpretation.
Institut de Ciències de l'Espai1, Autonomous University of Barcelona2, University of Illinois at Urbana–Champaign3, University of Cambridge4, Fermilab5, National Center for Supercomputing Applications6, University College London7, University of Chicago8, ETH Zurich9, Spanish National Research Council10, Stanford University11, SLAC National Accelerator Laboratory12, Lawrence Berkeley National Laboratory13, Rhodes University14, University of Pennsylvania15, Institut d'Astrophysique de Paris16, Ludwig Maximilian University of Munich17, California Institute of Technology18, University of Michigan19, Max Planck Society20, Ohio State University21, Australian Astronomical Observatory22, Texas A&M University23, University of São Paulo24, University of Sussex25, Universidade Federal do Rio Grande do Sul26, Argonne National Laboratory27, University of Manchester28
TL;DR: In this article, the authors study the clustering of galaxies detected at i < 22.5 in the Science Verification observations of the Dark Energy Survey (DES) and assess the impact of photometric redshift errors by comparing results using a template-based photo-z algorithm (BPZ) to a machine-learning algorithm (TPZ).
Abstract: 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 Deltaz = 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-z algorithm (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 measure galaxy bias over a broad range of linear scales relative to mass clustering predicted from the Planck Lambda cold dark matter model, finding agreement with the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) measurements with chi2 of 4.0 (8.7) with 5 degrees of freedom for the TPZ (BPZ) redshifts. 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 per cent accuracy down to scales at least 4-10 times smaller than those on which linear theory is expected to be sufficient.
Ohio State University1, Autonomous University of Barcelona2, University College London3, University of Manchester4, Institut de Ciències de l'Espai5, Stanford University6, Brookhaven National Laboratory7, Rhodes University8, Fermilab9, University of Cambridge10, Institut d'Astrophysique de Paris11, University of Illinois at Urbana–Champaign12, National Center for Supercomputing Applications13, Institute of Cosmology and Gravitation, University of Portsmouth14, Texas A&M University15, Ludwig Maximilian University of Munich16, California Institute of Technology17, University of Pennsylvania18, University of Michigan19, University of Chicago20, Max Planck Society21, Australian Astronomical Observatory22, University of São Paulo23, Catalan Institution for Research and Advanced Studies24, Argonne National Laboratory25
TL;DR: In this paper, a new measurement method is proposed to minimize the wastage of data for any class of stars or galaxies detectable in an imaging survey, which can be used to estimate the number of stars and galaxies in the sky.
Abstract: Accurate statistical measurement with large imaging surveys has traditionally required throwing away a sizable fraction of the data. This is because most measurements have have relied on selecting nearly complete samples, where variations in the composition of the galaxy population with seeing, depth, or other survey characteristics are small. We introduce a new measurement method that aims to minimize this wastage, allowing precision measurement for any class of stars or galaxies detectable in an imaging survey. We have implemented our proposal in Balrog, a software package which embeds fake objects in real imaging in order to accurately characterize measurement biases. We also demonstrate this technique with an angular clustering measurement using Dark Energy Survey (DES) data. We first show that recovery of our injected galaxies depends on a wide variety of survey characteristics in the same way as the real data. We then construct a flux-limited sample of the faintest galaxies in DES, chosen specifically for their sensitivity to depth and seeing variations. Using the synthetic galaxies as randoms in the standard LandySzalay correlation function estimator suppresses the effects of variable survey selection by at least two orders of magnitude. Now our measured angular clustering is found to be inmore » excellent agreement with that of a matched sample drawn from much deeper, higherresolution space-based COSMOS imaging; over angular scales of 0.004° < θ < 0.2 ° , we find a best-fit scaling amplitude between the DES and COSMOS measurements of 1.00 ± 0.09. We expect this methodology to be broadly useful for extending the statistical reach of measurements in a wide variety of coming imaging surveys.« less
Fermilab1, Harvard University2, University of Pennsylvania3, University of Illinois at Urbana–Champaign4, Space Telescope Science Institute5, Sao Paulo State University6, Rhodes University7, University College London8, Princeton University9, University of Cambridge10, University of Paris11, Carnegie Institution for Science12, Syracuse University13, Stanford University14, University of Portsmouth15, University of Maryland, College Park16, Goddard Space Flight Center17, Ohio University18, University of Southampton19, Ludwig Maximilian University of Munich20, California Institute of Technology21, University of Michigan22, Cardiff University23, University of Arizona24, Pennsylvania State University25, Los Alamos National Laboratory26, Lawrence Berkeley National Laboratory27, University of California, Berkeley28, Ohio State University29, Australian Astronomical Observatory30, Texas A&M University31, University of São Paulo32, New York University33, Columbia University34, Max Planck Society35, University of Sussex36, Brookhaven National Laboratory37, Argonne National Laboratory38
TL;DR: In this paper, the results of a deep search for an optical counterpart to the GW150914, the first trigger from the Advanced LIGO GW detectors, were reported.
Abstract: We report the results of a deep search for an optical counterpart to the gravitational wave (GW) event GW150914, the first trigger from the Advanced LIGO GW detectors. We used the Dark Energy Camera (DECam) to image a 102 deg2 area, corresponding to 38% of the initial trigger high-probability sky region and to 11% of the revised high-probability region. We observed in the i and z bands at 4–5, 7, and 24 days after the trigger. The median 5σ point-source limiting magnitudes of our search images are i = 22.5 and z = 21.8 mag. We processed the images through a difference-imaging pipeline using templates from pre-existing Dark Energy Survey data and publicly available DECam data. Due to missing template observations and other losses, our effective search area subtends 40 deg2, corresponding to a 12% total probability in the initial map and 3% in the final map. In this area, we search for objects that decline significantly between days 4–5 and day 7, and are undetectable by day 24, finding none to typical magnitude limits of i = 21.5, 21.1, 20.1 for object colors (i − z) = 1, 0, −1, respectively. Our search demonstrates the feasibility of a dedicated search program with DECam and bodes well for future research in this emerging field.
Max Planck Society1, ETH Zurich2, University of Portsmouth3, Autonomous University of Barcelona4, University of Pennsylvania5, Stanford University6, Ludwig Maximilian University of Munich7, University of Arizona8, Brookhaven National Laboratory9, University of Manchester10, Argonne National Laboratory11, Rhodes University12, University College London13, Fermilab14, Princeton University15, University of Cambridge16, Carnegie Institution for Science17, University of Paris18, University of Illinois at Urbana–Champaign19, University of Southampton20, Texas A&M University21, California Institute of Technology22, University of Michigan23, Ohio State University24, Australian Astronomical Observatory25, University of São Paulo26, University of Sussex27
TL;DR: In this article, the authors measured the weak lensing shear around galaxy troughs, i.e., the radial alignment of background galaxies relative to underdensities in projections of the foreground galaxy field over a wide range of redshift in Science Verification data from the Dark Energy Survey.
Abstract: We measure the weak lensing shear around galaxy troughs, i.e. the radial alignment of background galaxies relative to underdensities in projections of the foreground galaxy field over a wide range of redshift in Science Verification data from the Dark Energy Survey. Our detection of the shear signal is highly significant (10σ–15σ for the smallest angular scales) for troughs with the redshift range z ∈ [0.2, 0.5] of the projected galaxy field and angular diameters of 10 arcmin…1°. These measurements probe the connection between the galaxy, matter density, and convergence fields. By assuming galaxies are biased tracers of the matter density with Poissonian noise, we find agreement of our measurements with predictions in a fiducial Λ cold dark matter model. The prediction for the lensing signal on large trough scales is virtually independent of the details of the underlying model for the connection of galaxies and matter. Our comparison of the shear around troughs with that around cylinders with large galaxy counts is consistent with a symmetry between galaxy and matter over- and underdensities. In addition, we measure the two-point angular correlation of troughs with galaxies which, in contrast to the lensing signal, is sensitive to galaxy bias on all scales. The lensing signal of troughs and their clustering with galaxies is therefore a promising probe of the statistical properties of matter underdensities and their connection to the galaxy field.
TL;DR: Abbott et al. as mentioned in this paper compared the four probability sky maps produced for the gravitational-wave transient GW150914, and provided additional details of the EM follow-up observations that were performed in the different bands.
Abstract: This Supplement provides supporting material for Abbott et al. (2016a). We briefly summarize past electromagnetic (EM) follow-up efforts as well as the organization and policy of the current EM follow-up program. We compare the four probability sky maps produced for the gravitational-wave transient GW150914, and provide additional details of the EM follow-up observations that were performed in the different bands.
University of Pennsylvania1, University of Cambridge2, Fermilab3, University of Chicago4, University of Michigan5, Argonne National Laboratory6, Institut de Ciències de l'Espai7, University College London8, IFAE9, Stanford University10, University of Manchester11, Rhodes University12, Princeton University13, Institut d'Astrophysique de Paris14, Carnegie Learning15, University of Illinois at Urbana–Champaign16, National Center for Supercomputing Applications17, McGill University18, Ludwig Maximilian University of Munich19, SLAC National Accelerator Laboratory20, University of California, Berkeley21, Ohio State University22, Australian Astronomical Observatory23, University of São Paulo24, Texas A&M University25, Catalan Institution for Research and Advanced Studies26, Max Planck Society27, California Institute of Technology28, University of Melbourne29, University of Sussex30, Brookhaven National Laboratory31, Harvard University32, Institute of Cosmology and Gravitation, University of Portsmouth33
TL;DR: In this article, the correlation of galaxy lensing and cosmic microwave background lensing with a set of galaxies expected to trace the matter density field was measured using pre-survey Dark Energy Survey (DES) Science Verification optical imaging data and millimetre-wave data from the 2500 sq. deg. South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) survey.
Abstract: We measure the correlation of galaxy lensing and cosmic microwave background lensing with a set of galaxies expected to trace the matter density field. The measurements are performed using pre-survey Dark Energy Survey (DES) Science Verification optical imaging data and millimetre-wave data from the 2500 sq. deg. South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) survey. The two lensing-galaxy correlations are jointly fit to extract constraints on cosmological parameters, constraints on the redshift distribution of the lens galaxies, and constraints on the absolute shear calibration of DES galaxy-lensing measurements. We show that an attractive feature of these fits is that they are fairly insensitive to the clustering bias of the galaxies used as matter tracers. The measurement presented in this work confirms that DES and SPT data are consistent with each other and with the currently favoured Lambda cold dark matter cosmological model. It also demonstrates that joint lensing-galaxy correlation measurement considered here contains a wealth of information that can be extracted using current and future surveys.
TL;DR: In this paper, the authors used simulated galaxy surveys to study how galaxy membership in redMaPPer clusters maps to the underlying halo population, and the accuracy of a mean dynamical cluster mass, derived from stacked pairwise spectroscopy of clusters with richness.
Abstract: We use simulated galaxy surveys to study: i) how galaxy membership in redMaPPer clusters maps to the underlying halo population, and ii) the accuracy of a mean dynamical cluster mass, $M_\sigma(\lambda)$, derived from stacked pairwise spectroscopy of clusters with richness $\lambda$. Using $\sim\! 130,000$ galaxy pairs patterned after the SDSS redMaPPer cluster sample study of Rozo et al. (2015 RMIV), we show that the pairwise velocity PDF of central--satellite pairs with $m_i < 19$ in the simulation matches the form seen in RMIV. Through joint membership matching, we deconstruct the main Gaussian velocity component into its halo contributions, finding that the top-ranked halo contributes $\sim 60\%$ of the stacked signal. The halo mass scale inferred by applying the virial scaling of Evrard et al. (2008) to the velocity normalization matches, to within a few percent, the log-mean halo mass derived through galaxy membership matching. We apply this approach, along with mis-centering and galaxy velocity bias corrections, to estimate the log-mean matched halo mass at $z=0.2$ of SDSS redMaPPer clusters. Employing the velocity bias constraints of Guo et al. (2015), we find $\langle \ln(M_{200c})|\lambda \rangle = \ln(M_{30}) + \alpha_m \ln(\lambda/30)$ with $M_{30} = 1.56 \pm 0.35 \times 10^{14} M_\odot$ and $\alpha_m = 1.31 \pm 0.06_{stat} \pm 0.13_{sys}$. Systematic uncertainty in the velocity bias of satellite galaxies overwhelmingly dominates the error budget.
University College London1, McGill University2, University of Chicago3, ETH Zurich4, University of Cambridge5, University of Portsmouth6, Fermilab7, University of Pennsylvania8, University of Manchester9, Stanford University10, University of Illinois at Urbana–Champaign11, Argonne National Laboratory12, Rhodes University13, Carnegie Institution for Science14, University of Southampton15, Ludwig Maximilian University of Munich16, California Institute of Technology17, University of Michigan18, University of California, Berkeley19, Lawrence Berkeley National Laboratory20, Ohio State University21, Australian Astronomical Observatory22, University of São Paulo23, Princeton University24, University of Melbourne25, University of Arizona26, Sao Paulo State University27, Max Planck Society28
TL;DR: In this paper, the authors measured the cross-correlation between weak lensing of galaxy images and the cosmic microwave background (CMB) using galaxy shape measurements from 139 deg(2) of the DES Science Verification data and overlapping CMB lensing from the South Pole Telescope (SPT) and Planck.
Abstract: We measure the cross-correlation between weak lensing of galaxy images and of the cosmic microwave background (CMB). The effects of gravitational lensing on different sources will be correlated if the lensing is caused by the same mass fluctuations. We use galaxy shape measurements from 139 deg(2) of the Dark Energy Survey (DES) Science Verification data and overlapping CMB lensing from the South Pole Telescope (SPT) and Planck. The DES source galaxies have a median redshift of z(med) similar to 0.7, while the CMB lensing kernel is broad and peaks at z similar to 2. The resulting cross-correlation is maximally sensitive to mass fluctuations at z similar to 0.44. Assuming the Planck 2015 best-fitting cosmology, the amplitude of the DESxSPT cross-power is found to be A(SPT) = 0.88 +/- 0.30 and that from DESxPlanck to be A(Planck) = 0.86 +/- 0.39, where A = 1 corresponds to the theoretical prediction. These are consistent with the expected signal and correspond to significances of 2.9 sigma and 2.2 sigma, respectively. We demonstrate that our results are robust to a number of important systematic effects including the shear measurement method, estimator choice, photo-z uncertainty and CMB lensing systematics. We calculate a value of A = 1.08 +/- 0.36 for DESxSPT when we correct the observations with a simple intrinsic alignment model. With three measurements of this cross-correlation now existing in the literature, there is not yet reliable evidence for any deviation from the expected LCDM level of cross-correlation. We provide forecasts for the expected signal-to-noise ratio of the combination of the five-year DES survey and SPT-3G.
University of Michigan1, University of Sussex2, Yale University3, Korea Astronomy and Space Science Institute4, Ludwig Maximilian University of Munich5, University of Portsmouth6, Santa Cruz Institute for Particle Physics7, Liverpool John Moores University8, University of KwaZulu-Natal9, University of Manchester10, University of Edinburgh11, Texas A&M University12, University of Oxford13, Fermilab14, University of Porto15, Rhodes University16, University College London17, University of Cambridge18, Institut de Ciències de l'Espai19, Institut d'Astrophysique de Paris20, Stanford University21, SLAC National Accelerator Laboratory22, California Institute of Technology23, University of Pennsylvania24, Autonomous University of Barcelona25, University of Chicago26, Max Planck Society27, University of Illinois at Urbana–Champaign28, Ohio State University29, Australian Astronomical Observatory30, Brookhaven National Laboratory31, Argonne National Laboratory32
TL;DR: In this article, the stellar mass growth of bright central galaxies (BCGs) since redshift z = 1.2 was studied and compared with the expectation in a semi-analytical model applied to the Millennium Simulation.
Abstract: Using the science verification data of the Dark Energy Survey for a new sample of 106 X-ray selected clusters and groups, we study the stellar mass growth of bright central galaxies (BCGs) since redshift z ~ 1.2. Compared with the expectation in a semi-analytical model applied to the Millennium Simulation, the observed BCGs become under-massive/under-luminous with decreasing redshift. We incorporate the uncertainties associated with cluster mass, redshift, and BCG stellar mass measurements into an analysis of a redshift-dependent BCG-cluster mass relation, {m}*∝ ({M}200}/{1.5×{10}14{M}s}) 0.24+/-0.08(1+z)-0.19+/- 0.34, and compare the observed relation to the model prediction. We estimate the average growth rate since z = 1.0 for BCGs hosted by clusters of M200,z = 1013.8 Ms at z = 1.0: m*,BCG appears to have grown by 0.13 ± 0.11 dex, in tension at the ˜2.5sigma significance level with the 0.40 dex growth rate expected from the semi-analytic model. We show that the build-up of extended intracluster light after z = 1.0 may alleviate this tension in BCG growth rates.
Max Planck Society1, University of Bonn2, Liverpool John Moores University3, University of Utah4, École Polytechnique Fédérale de Lausanne5, Aix-Marseille University6, University of Arizona7, SLAC National Accelerator Laboratory8, Academy of Sciences of Uzbekistan9, Academia Sinica Institute of Astronomy and Astrophysics10, Leibniz Institute for Astrophysics Potsdam11, Ohio University12, New York University13
TL;DR: Alfred P. Sloan Foundation, US Department of Energy Office of Science; Center for High Performance Computing at the University of Utah; Brazilian Participation Group, Carnegie Institution for Science; Carnegie Mellon University; Chilean Participation Group; French Participation Group and Harvard-Smithsonian Center for Astrophysics; Instituto de Astrofisica de Canarias; Johns Hopkins University; Kavli Institute for the Physics and Mathematics of the Universe (IPMU)/University of Tokyo; Lawrence Berkeley National Laboratory; Leibniz Institut fur Astrophysik Potsdam (A
Abstract: Alfred P. Sloan Foundation; US Department of Energy Office of Science; Center for High-Performance Computing at the University of Utah; Brazilian Participation Group; Carnegie Institution for Science; Carnegie Mellon University; Chilean Participation Group; French Participation Group; Harvard-Smithsonian Center for Astrophysics; Instituto de Astrofisica de Canarias; Johns Hopkins University; Kavli Institute for the Physics and Mathematics of the Universe (IPMU)/University of Tokyo; Lawrence Berkeley National Laboratory; Leibniz Institut fur Astrophysik Potsdam (AIP); Max-Planck-Institut fur Astronomie (MPIA Heidelberg); Max-Planck-Institut fur Astrophysik (MPA Garching); Max-Planck-Institut fur Extraterrestrische Physik (MPE); National Astronomical Observatory of China; New Mexico State University; New York University; University of Notre Dame; Observatario Nacional/MCTI; Ohio State University; Pennsylvania State University; Shanghai Astronomical Observatory; United Kingdom Participation Group; Universidad Nacional Autonoma de Mexico; University of Arizona; University of Colorado Boulder; University of Oxford; University of Portsmouth; University of Utah; University of Virginia; University of Washington; University of Wisconsin; Vanderbilt University; Yale University; German BMWI through the Verbundforschung [50 OR 1506]; National Science Foundation
Fermilab1, Harvard University2, University of Pennsylvania3, University of Illinois at Urbana–Champaign4, Space Telescope Science Institute5, Sao Paulo State University6, University College London7, Rhodes University8, Princeton University9, University of Cambridge10, University of Paris11, Carnegie Institution for Science12, Syracuse University13, Stanford University14, University of Portsmouth15, Goddard Space Flight Center16, University of Maryland, College Park17, Ohio University18, University of Southampton19, Ludwig Maximilian University of Munich20, California Institute of Technology21, University of Michigan22, Cardiff University23, University of Arizona24, Pennsylvania State University25, Los Alamos National Laboratory26, Lawrence Berkeley National Laboratory27, University of California, Berkeley28, Ohio State University29, Australian Astronomical Observatory30, Texas A&M University31, University of São Paulo32, New York University33, Columbia University34, Max Planck Society35, University of Sussex36, Brookhaven National Laboratory37, Argonne National Laboratory38
TL;DR: In this article, a deep search for an optical counterpart to the GW150914, the first trigger from the Advanced LIGO gravitational wave detectors, was conducted using the DECam.
Abstract: We report initial results of a deep search for an optical counterpart to the gravitational wave event GW150914, the first trigger from the Advanced LIGO gravitational wave detectors. We used the Dark Energy Camera (DECam) to image a 102 deg$^2$ area, corresponding to 38% of the initial trigger high-probability sky region and to 11% of the revised high-probability region. We observed in i and z bands at 4-5, 7, and 24 days after the trigger. The median $5\sigma$ point-source limiting magnitudes of our search images are i=22.5 and z=21.8 mag. We processed the images through a difference-imaging pipeline using templates from pre-existing Dark Energy Survey data and publicly available DECam data. Due to missing template observations and other losses, our effective search area subtends 40 deg$^{2}$, corresponding to 12% total probability in the initial map and 3% of the final map. In this area, we search for objects that decline significantly between days 4-5 and day 7, and are undetectable by day 24, finding none to typical magnitude limits of i= 21.5,21.1,20.1 for object colors (i-z)=1,0,-1, respectively. Our search demonstrates the feasibility of a dedicated search program with DECam and bodes well for future research in this emerging field.
TL;DR: In this paper, the authors summarize past electromagnetic follow-up efforts as well as the organization and policy of the current EM followup program and compare the four probability sky maps produced for the gravitational-wave transient GW150914, and provide additional details of the EM follow up observations that were performed in the different bands.
Abstract: This Supplement provides supporting material for arXiv:1602.08492 . We briefly summarize past electromagnetic (EM) follow-up efforts as well as the organization and policy of the current EM follow-up program. We compare the four probability sky maps produced for the gravitational-wave transient GW150914, and provide additional details of the EM follow-up observations that were performed in the different bands.