Artículos de revistas
Dark Energy Survey year 1 results: Cosmological constraints from galaxy clustering and weak lensing
Fecha
2018-08-15Registro en:
Physical Review D, v. 98, n. 4, 2018.
2470-0029
2470-0010
10.1103/PhysRevD.98.043526
2-s2.0-85052611363
Autor
National Optical Astronomy Observatory
Rhodes University
University College London
IEEC-CSIC
Barcelona Institute of Science and Technology
Fermi National Accelerator Laboratory
Stanford University
ETH Zurich
University of Queensland
ARC Centre of Excellence for All-sky Astrophysics (CAASTRO)
University of Portsmouth
Universidad Autonoma de Madrid
University of Surrey
University of Cambridge
Witmer Hall
SLAC National Accelerator Laboratory
University of Pennsylvania
LSST
Institut d'Astrophysique de Paris
University of Chicago
Observatoire de Sauverny
Ohio State University
University of Manchester
Universidade Estadual Paulista (UNESP)
Laboratório Interinstitucional de E-Astronomia - LIneA
Observatório Nacional
National Center for Supercomputing Applications
University of Illinois
University of Southampton
School of Physics and Astronomy
University of Michigan
Medioambientales y Tecnológicas (CIEMAT)
Texas A and M University
IIT Hyderabad
Excellence Cluster Universe
Ludwig-Maximilians-Universität
California Institute of Technology
University of Edinburgh
Ludwig-Maximilians Universität München
Max Planck Institute for Extraterrestrial Physics
Swinburne University of Technology
501 Campbell Hall
Lawrence Berkeley National Laboratory
University of Washington
Santa Cruz Institute for Particle Physics
Universidade de São Paulo (USP)
Australian Astronomical Observatory
Argonne National Laboratory
Centro Brasileiro de Pesquisas Físicas
Peyton Hall
Institució Catalana de Recerca i Estudis Avançats
Australian National University
University of Sussex
University of Arizona
UFRGS
Brookhaven National Laboratory
Dept. Physics-Astronomy
Universidade Estadual de Campinas (UNICAMP)
Oak Ridge National Laboratory
Chinese Academy of Sciences
Institución
Resumen
We present cosmological results from a combined analysis of galaxy clustering and weak gravitational lensing, using 1321 deg2 of griz imaging data from the first year of the Dark Energy Survey (DES Y1). We combine three two-point functions: (i) the cosmic shear correlation function of 26 million source galaxies in four redshift bins, (ii) the galaxy angular autocorrelation function of 650,000 luminous red galaxies in five redshift bins, and (iii) the galaxy-shear cross-correlation of luminous red galaxy positions and source galaxy shears. To demonstrate the robustness of these results, we use independent pairs of galaxy shape, photometric-redshift estimation and validation, and likelihood analysis pipelines. To prevent confirmation bias, the bulk of the analysis was carried out while blind to the true results; we describe an extensive suite of systematics checks performed and passed during this blinded phase. The data are modeled in flat ΛCDM and wCDM cosmologies, marginalizing over 20 nuisance parameters, varying 6 (for ΛCDM) or 7 (for wCDM) cosmological parameters including the neutrino mass density and including the 457×457 element analytic covariance matrix. We find consistent cosmological results from these three two-point functions and from their combination obtain S8≡σ8(Ωm/0.3)0.5=0.773-0.020+0.026 and Ωm=0.267-0.017+0.030 for ΛCDM; for wCDM, we find S8=0.782-0.024+0.036, Ωm=0.284-0.030+0.033, and w=-0.82-0.20+0.21 at 68% C.L. The precision of these DES Y1 constraints rivals that from the Planck cosmic microwave background measurements, allowing a comparison of structure in the very early and late Universe on equal terms. Although the DES Y1 best-fit values for S8 and Ωm are lower than the central values from Planck for both ΛCDM and wCDM, the Bayes factor indicates that the DES Y1 and Planck data sets are consistent with each other in the context of ΛCDM. Combining DES Y1 with Planck, baryonic acoustic oscillation measurements from SDSS, 6dF, and BOSS and type Ia supernovae from the Joint Lightcurve Analysis data set, we derive very tight constraints on cosmological parameters: S8=0.802±0.012 and Ωm=0.298±0.007 in ΛCDM and w=-1.00-0.04+0.05 in wCDM. Upcoming Dark Energy Survey analyses will provide more stringent tests of the ΛCDM model and extensions such as a time-varying equation of state of dark energy or modified gravity.