Kavli Affiliate: Chihway Chang
| First 5 Authors: Jazmine Jefferson, Jazmine Jefferson, , ,
| Summary:
In recent years, shear catalogs have been released by various Stage-III weak
lensing surveys including the Kilo-Degree Survey, the Dark Energy Survey, and
the Hyper Suprime-Cam Subaru Strategic Program. These shear catalogs have
undergone rigorous validation tests to ensure that the residual shear
systematic effects in the catalogs are subdominant relative to the statistical
uncertainties, such that the resulting cosmological constraints are unbiased.
While there exists a generic set of tests that are designed to probe certain
systematic effects, the implementations differ slightly across the individual
surveys, making it difficult to make direct comparisons. In this paper, we use
the TXPipe package to conduct a series of predefined diagnostic tests across
three public shear catalogs — the 1,000 deg$^2$ KiDS-1000 shear catalog, the
Year 3 DES-Y3 shear catalog, and the Year 3 HSC-Y3 shear catalog. We attempt to
reproduce the published results when possible and perform key tests uniformly
across the surveys. While all surveys pass most of the null tests in this
study, we find two tests where some of the surveys fail. Namely, we find that
when measuring the tangential ellipticity around bright and faint star samples,
KiDS-1000 fails with a chi^2$/dof of 121.1/16 and 257.7/16 for bins 4 and 5
for faint, weighted stars. We also find that DES-Y3 and HSC-Y3 fail the
$B$-mode test when estimated with the Hybrid-$E$/$B$ method, with a
$chi^2$/dof of 37.9/10 and 36.0/8 for the fourth and third autocorrelation
bins. We assess the impacts on the $Omega_rm m$ – S$_8$ parameter space
by comparing the posteriors of a simulated data vector with and without PSF
contamination — we find negligible effects in all cases. Finally, we propose
strategies for performing these tests on future surveys such as the Vera C.
Rubin Observatory’s Legacy Survey of Space and Time.
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