KiDS-1000 catalogue: Weak gravitational lensing shear measurements
Benjamin Giblin, Catherine Heymans, Marika Asgari, Hendrik Hildebrandt, Henk Hoekstra, Benjamin Joachimi, Arun Kannawadi, Konrad Kuijken, Chieh-An Lin, Lance Miller, Tilman Tröster, Jan Luca van den Busch, Angus H. Wright, Maciej Bilicki, Chris Blake, Jelte de Jong, Andrej Dvornik, Thomas Erben, Fedor Getman, Nicola R. Napolitano, Peter Schneider, HuanYuan Shan, Edwin Valentijn
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 6.17 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 σ change in the inferred cosmic shear constraints on the clustering cosmological parameter S 8 = σ 8 √Ω 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. The 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.