Suchergebnisse

U.S. Department of Energy ; U.S. 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 andAstro-Particle Physics at the Ohio State University ; Mitchell Institute for Fundamental Physics and Astronomy at Texas AM University ; Financiadora de Estudos e Projetos ; Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) ; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) ; Ministerio da Ciencia ; Tecnologia e Inovacao ; Deutsche Forschungsgemeinschaft ; Collaborating Institutions in the Dark Energy Survey ; National Science Foundation ; MINECO ; Centro de Excelencia Severo Ochoa ; European Research Council under the European Union's Seventh Framework Programme (FP7)/including ERC grant ; NASA through the Einstein Fellowship Program ; ICREA ; Science and Technology Facilities Council ; National Science Foundation: AST-1138766 ; MINECO: AYA2012-39559 ; MINECO: ESP2013-48274 ; MINECO: FPA2013-47986 ; Centro de Excelencia Severo Ochoa: SEV-2012-0234 ; European Research Council under the European Union's Seventh Framework Programme (FP7)/including ERC grant: 240672 ; European Research Council under the European Union's Seventh Framework Programme (FP7)/including ERC grant: 291329 ; European Research Council under the European Union's Seventh Framework Programme (FP7)/including ERC grant: 306478 ; NASA through the Einstein Fellowship Program: PF5-160138 ; Science and Technology Facilities Council: ST/L000768/1 ; Science and Technology Facilities Council: ST/M001334/1 ; Cosmic voids are usually identified in spectroscopic galaxy surveys, where 3D information about the large-scale structure of the Universe is available. Although an increasing amount of photometric data is being produced, its potential for void studies is limited since photometric redshifts induce line-of-sight position errors of >= 50 Mpc h(-1)which can render many voids undetectable. We present a new void finder designed for photometric surveys, validate it using simulations, and apply it to the high-quality photo-z redMaGiC galaxy sample of the DES Science Verification data. The algorithm works by projecting galaxies into 2D slices and finding voids in the smoothed 2D galaxy density field of the slice. Fixing the line-of-sight size of the slices to be at least twice the photo-z scatter, the number of voids found in simulated spectroscopic and photometric galaxy catalogues is within 20 per cent for all transverse void sizes, and indistinguishable for the largest voids (R-v >= 70 Mpc h(-1)). The positions, radii, and projected galaxy profiles of photometric voids also accurately match the spectroscopic void sample. Applying the algorithm to the DES-SV data in the redshift range 0.2 < z < 0.8, we identify 87 voids with comoving radii spanning the range 18-120 Mpc h(-1), and carry out a stacked weak lensing measurement. With a significance of 4.4 sigma, the lensing measurement confirms that the voids are truly underdense in the matter field and hence not a product of Poisson noise, tracer density effects or systematics in the data. It also demonstrates, for the first time in real data, the viability of void lensing studies in photometric surveys.

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 ; Center for Particle Cosmology at the University of Pennsylvania ; Warren Center at the University of Pennsylvania ; Mitchell Institute for Fundamental Physics and Astronomy at Texas AM University ; Financiadora de Estudos e Projetos ; Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) ; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) ; Ministerio da Ciencia e Tecnologia ; Deutsche Forschungsgemeinschaft ; National Science Foundation ; MINECO ; Centro de Excelencia Severo Ochoa ; European Union ; Argonne National Laboratory ; University of California at Santa Cruz ; University of Cambridge ; University of Chicago ; University College London ; DES-Brazil Consortium ; Eidgenossische Technische Hochschule (ETH) Zurich ; Fermi National Accelerator Laboratory ; University of Edinburgh ; 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 ; associated Excellence Cluster Universe ; University of Michigan ; National Optical Astronomy Observatory ; University of Nottingham ; Ohio State University ; University of Pennsylvania ; University of Portsmouth ; University of Sussex ; Texas AM University ; SLAC National Accelerator Laboratory ; Stanford University ; Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas-Madrid ; Science and Technology Facilities Council ; ICREA ; National Science Foundation: AST-1138766 ; MINECO: AYA2012-39559 ; MINECO: ESP2013-48274 ; MINECO: FPA2013-47986 ; Centro de Excelencia Severo Ochoa: SEV-2012-0234 ; Science and Technology Facilities Council: ST/M001334/1 ; Science and Technology Facilities Council: ST/L000768/1 ; We present cosmological constraints from the Dark Energy Survey (DES) using a combined analysis of angular clustering of red galaxies and their cross-correlation with weak gravitational lensing of background galaxies. We use a 139 deg(2) contiguous patch of DES data from the Science Verification (SV) period of observations. Using large-scale measurements, we constrain the matter density of the Universe as Omega(m) = 0.31 +/- 0.09 and the clustering amplitude of the matter power spectrum as sigma(8) = 0.74 +/- 0.13 after marginalizing over seven nuisance parameters and three additional cosmological parameters. This translates into S-8 = sigma(8)(Omega(m)/0.3)(0.16) = 0.74 +/- 0.12 for our fiducial lens redshift bin at 0.35 < z < 0.5, while S-8 = 0.78 +/- 0.09 using two bins over the range 0.2 < z < 0.5. We study the robustness of the results under changes in the data vectors, modelling and systematics treatment, including photometric redshift and shear calibration uncertainties, and find consistency in the derived cosmological parameters. We show that our results are consistent with previous cosmological analyses from DES and other data sets and conclude with a joint analysis of DES angular clustering and galaxy-galaxy lensing with Planck Cosmic Microwave Background data, baryon accoustic oscillations and Supernova Type Ia measurements.

U.S. Department of Energy ; U.S. 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 ; Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) ; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) ; Ministerio da Ciencia, Tecnologia e Inovacao ; Deutsche Forschungsgemeinschaft ; 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 ; National Science Foundation ; MINECO ; Centro de Excelencia Severo Ochoa ; European Research Council under the European Union ; ERC ; NSF Physics Frontier Center ; Kavli Foundation ; Gordon and Betty Moore Foundation ; European Research Council ; CNES ; Royal Society of New Zealand Rutherford Foundation Trust ; Cambridge Commonwealth Trust ; University of Melbourne ; DOE ; ICREA ; Science and Technology Facilities Council ; National Science Foundation: AST-1138766 ; National Science Foundation: PLR-1248097 ; MINECO: AYA2012-39559 ; MINECO: ESP2013-48274 ; MINECO: FPA2013-47986 ; Centro de Excelencia Severo Ochoa: SEV-2012-0234 ; ERC: 240672 ; ERC: 291329 ; ERC: 306478 ; NSF Physics Frontier Center: PHY-0114422 ; Gordon and Betty Moore Foundation: 947 ; European Research Council: FP7/291329 ; DOE: DE-AC02-98CH10886 ; Science and Technology Facilities Council: ST/K00090X/1 ; Science and Technology Facilities Council: ST/N000668/1 ; Science and Technology Facilities Council: ST/L000768/1 ; Science and Technology Facilities Council: ST/M001334/1 ; 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.

Ohio State University Center for Cosmology and AstroParticle Physics ; Spanish Ramon y Cajal MICINN program ; Spanish Ministerio de Economia y Competitividad ; Juan de la Cierva fellowship ; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) ; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) ; 'Plan Estatal de Investigacion Cientfica y Tecnica y de Innovacion' program of the Spanish government ; U.S. Department of Energy ; U.S. 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 ; Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) ; Ministerio da Ciencia, Tecnologia e Inovacao ; Deutsche Forschungsgemeinschaft ; 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 ; OzDES Membership Consortium ; National Science Foundation ; MINECO ; ERDF funds from the European Union ; CERCA program of the Generalitat de Catalunya ; European Research Council under the European Union ; ERC ; Australian Research Council Centre of Excellence ; U.S. Department of Energy, Office of Science, Office of High Energy Physics ; Spanish Ministerio de Economia y Competitividad: ESP2013-48274-C3-1-P ; CNPq: 465376/2014-2 ; National Science Foundation: AST-1138766 ; National Science Foundation: AST-1536171 ; MINECO: AYA2015-71825 ; MINECO: ESP2015-66861 ; MINECO: FPA2015-68048 ; MINECO: SEV-2016-0588 ; MINECO: SEV-2016-0597 ; MINECO: MDM-2015-0509 ; ERC: 240672 ; ERC: 291329 ; ERC: 306478 ; Australian Research Council Centre of Excellence: CE110001020 ; U.S. Department of Energy, Office of Science, Office of High Energy Physics: DE-AC02-07CH11359 ; We present angular diameter distance measurements obtained by locating the baryon acoustic oscillations (BAO) scale in the distribution of galaxies selected from the first year of Dark Energy Survey data. We consider a sample of over 1.3 million galaxies distributed over a footprint of 1336 deg(2) with 0.6 < z(photo) < 1 and a typical redshift uncertainty of 0.03(1 + z). This sample was selected, as fully described in a companion paper, using a colour/magnitude selection that optimizes trade-offs between number density and redshift uncertainty. We investigate the BAO signal in the projected clustering using three conventions, the angular separation, the comoving transverse separation, and spherical harmonics. Further, we compare results obtained from template-based and machine-learning photometric redshift determinations. We use 1800 simulations that approximate our sample in order to produce covariance matrices and allow us to validate our distance scale measurement methodology. We measure the angular diameter distance, D-A, at the effective redshift of our sample divided by the true physical scale of the BAO feature, r(d). We obtain close to a 4 per cent distance measurement of D-A (z(eff )= 0.81)/r(d) = 10.75 +/- 0.43. These results are consistent with the flat A cold dark matter concordance cosmological model supported by numerous other recent experimental results.

U.S. Department of Energy ; U.S. 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 Ohio State University ; Mitchell Institute for Fundamental Physics and Astronomy at Texas AM University ; Financiadora de Estudos e Projetos ; Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) ; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) ; Ministerio da Ciencia, Tecnologia e Inovacao ; Deutsche Forschungsgemeinschaft ; 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 Zurich ; Fermi National Accelerator Laboratory ; University of Illinois at Urbana-Champaign ; Institut de Ciencies de l'Espai ; Institut de Fisica d'Altes Energies ; Lawrence Berkeley National Laboratory ; Ludwig-Maximilians Universitat Munchen ; 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 A M University ; OzDES Membership Consortium ; National Science Foundation ; MINECO ; European Union ; Centres de Recerce de Catalunya (CERCA) program of the Generalitat de Catalunya ; European Research Council under the European Union's Seventh Framework Program (FP7) ; Australian Research Council Centre of Excellence for All-sky Astrophysics ; U.S. Department of Energy, Office of Science, Office of High Energy Physics ; Office of Science of the U.S. Department of Energy ; National Science Foundation: AST-1138766 ; National Science Foundation: AST-1536171 ; MINECO: AYA2015-71825 ; MINECO: ESP2015-88861 ; MINECO: FPA2015-68048 ; MINECO: SEV-2012-0234 ; MINECO: SEV-2016-0597 ; MINECO: MDM-2015-0509, ; European Research Council under the European Union's Seventh Framework Program (FP7): 240672 ; European Research Council under the European Union's Seventh Framework Program (FP7): 291329 ; European Research Council under the European Union's Seventh Framework Program (FP7): 306478 ; Australian Research Council Centre of Excellence for All-sky Astrophysics: CE110001020 ; U.S. Department of Energy, Office of Science, Office of High Energy Physics: DE-AC02-07CH11359 ; Office of Science of the U.S. Department of Energy: DE-AC02-05CH11231 ; We present cosmological results from a combined analysis of galaxy clustering and weak gravitational lensing, using 1321 deg(2) 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 Lambda CDM and wCDM cosmologies, marginalizing over 20 nuisance parameters, varying 6 (for Lambda CDM) or 7 (for wCDM) cosmological parameters including the neutrino mass density and including the 457 x 457 element analytic covariance matrix. We find consistent cosmological results from these three two-point functions and from their combination obtain S-8 equivalent to sigma(8) (Omega(m)/0.3)(0.5) = 0.773(-0.020)(+0.026) and Omega(m) = 0.267(-0.017)(+0.030) for Lambda CDM; for wCDM, we find S-8 = 0.782(-0.024)(+0.036) , Omega(m) = 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 S-8 and Omega(m) are lower than the central values from Planck for both Lambda CDM and wCDM, the Bayes factor indicates that the DES Y1 and Planck data sets are consistent with each other in the context of Lambda CDM. 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: S-8 = 0.802 +/- 0.012 and Omega(m) = 0.298 +/- 0.007 in Lambda CDM and w = -1.00(-0.04)(+0.05) in wCDM. Upcoming Dark Energy Survey analyses will provide more stringent tests of the Lambda CDM model and extensions such as a time-varying equation of state of dark energy or modified gravity.