A unified cataloguelevel reanalysis of stageIII cosmic shear surveys
Abstract
Cosmological parameter constraints from recent galaxy imaging surveys are reaching percentlevel accuracy on the effective amplitude of the lensing signal, S_{8}. The upcoming Legacy Survey of Space and Time (LSST) of the Vera C. Rubin Observatory will produce subpercent level measurements of cosmological parameters, providing a milestone test of the ΛCDM model. To supply guidance to the upcoming LSST analysis, it is important to understand thoroughly the results from different recent galaxy imaging surveys and assess their consistencies. In this work, we perform a unified cataloguelevel reanalysis of three cosmic shear data sets: the first year data from the Dark Energy Survey (DESY1), the 1000 deg^{2} data set from the KiloDegree Survey (KiDS1000), and the first year data from the Hyper SuprimeCam Subaru Strategic Program (HSCY1). We utilize a pipeline developed and rigorously tested by the LSST Dark Energy Science Collaboration to perform the reanalysis and assess the robustness of the results to analysis choices. We find the S_{8} constraint to be robust to two different smallscale modelling approaches, and varying choices of cosmological priors. Our unified analysis allows the consistency of the surveys to be rigorously tested, and we find the three surveys to be statistically consistent. Due to the partially overlapping footprint, we model the crosscovariance between KiDS1000 and HSCY1 approximately when combining all three data sets, resulting in a 1.61.9 per cent constraint on S_{8} given different assumptions on the crosscovariance.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 April 2023
 DOI:
 10.1093/mnras/stad246
 arXiv:
 arXiv:2208.07179
 Bibcode:
 2023MNRAS.520.5016L
 Keywords:

 gravitational lensing: weak;
 catalogues;
 surveys;
 cosmological parameters;
 cosmology: observations;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 27 pages, 18 figures, to be submitted to MNRAS