Cosmology from cosmic shear with Dark Energy Survey science verification data

Romer, A K and The DES Collaboration, (2016) Cosmology from cosmic shear with Dark Energy Survey science verification data. Physical Review D, 94 (2). 022001. ISSN 1550-7998

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Abstract

We present the first constraints on cosmology from the Dark Energy Survey (DES), using weak lensing measurements from the preliminary Science Verification (SV) data. We use 139 square degrees of SV data, which is less than 3% of the full DES survey area. Using cosmic shear 2-point measurements over three redshift bins we find sigma8(Omegam/0.3 )0.5=0.81 ±0.06 (68% confidence), after marginalizing over 7 systematics parameters and 3 other cosmological parameters. We examine the robustness of our results to the choice of data vector and systematics assumed, and find them to be stable. About 20% of our error bar comes from marginalizing over shear and photometric redshift calibration uncertainties. The current state-of-the-art cosmic shear measurements from CFHTLenS are mildly discrepant with the cosmological constraints from Planck CMB data; our results are consistent with both data sets. Our uncertainties are ˜30 % larger than those from CFHTLenS when we carry out a comparable analysis of the two data sets, which we attribute largely to the lower number density of our shear catalogue. We investigate constraints on dark energy and find that, with this small fraction of the full survey, the DES SV constraints make negligible impact on the Planck constraints. The moderate disagreement between the CFHTLenS and Planck values of sigma8(Omegam/0.3 )0.5 is present regardless of the value of w .

Item Type: Article
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Research Centres and Groups: Astronomy Centre
Subjects: Q Science > QB Astronomy
Depositing User: Richard Chambers
Date Deposited: 28 Nov 2016 08:09
Last Modified: 11 Sep 2017 19:42
URI: http://sro.sussex.ac.uk/id/eprint/65680

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Project NameSussex Project NumberFunderFunder Ref
STFC Consolidated Grant SupplementG1316STFC-SCIENCE AND TECHNOLOGY FACILITIES COUNCILST/M000753/1