Misc,
KiDS-1000 catalogue: weak gravitational lensing shear measurements
(2020)cite arxiv:2007.01845Comment: 24 pages, 11 figures, submitted to A&A. This paper is part of the KiDS-1000 series of papers, accompanying Joachimi et al. appearing on the arxiv today.
Abstract
We present weak lensing shear catalogues from the fourth data release of the
Kilo-Degree Survey, KiDS-1000, spanning 1006 square degrees of deep and
high-resolution imaging. Our `gold-sample' of galaxies, with well calibrated
photometric redshift distributions, consists of 21 million galaxies with an
effective number density of $6.2$ galaxies per square arcminute. We
quantify the accuracy of the spatial, temporal and flux-dependent point-spread
function (PSF) model, verifying that the model meets our requirements to induce
less than a $0.1\sigma$ change in the inferred cosmic shear constraints on the
clustering cosmological parameter $S_8 = \sigma_8Ømega_m/0.3$.
Through a series of two-point null-tests we validate the shear estimates,
finding no evidence for significant non-lensing B-mode distortions in the data.
PSF residuals are detected in the highest-redshift bins, originating from
object selection and/or weight bias. The amplitude is however shown to be
sufficiently low and within our stringent requirements. With a shear-ratio
null-test we verify the expected redshift scaling of the galaxy-galaxy lensing
signal around luminous red galaxies. We conclude that the joint KiDS-1000 shear
and photometric redshift calibration is sufficiently robust for combined-probe
gravitational lensing and spectroscopic clustering analyses.
