Clustering of red sequence galaxies in the fourth data release of the Kilo-Degree Survey

¹ Leiden Observatory, Leiden University, PO Box 9513 Leiden 2300 RA, The Netherlands
e-mail: vakili@strw.leidenuniv.nl
² Center for Theoretical Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-66 Warsaw, Poland
³ Ruhr-Universität Bochum, Astronomisches Institut (AIRUB), German Centre for Cosmological Lensing, Universitätsstr. 150, 44801 Bochum, Germany
⁴ Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK
⁵ School of Physics, Monash University, Clayton, VIC 3800, Australia
⁶ Argelander-Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany
⁷ Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
⁸ Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK
⁹ Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, NJ 08544, USA

Received: 30 August 2020
Accepted: 10 February 2023

Abstract

We present a sample of luminous red sequence galaxies as the basis for a study of the large-scale structure in the fourth data release of the Kilo-Degree Survey. The selected galaxies are defined by a red sequence template, in the form of a data-driven model of the colour-magnitude relation conditioned on redshift. In this work, the red sequence template was built using the broad-band optical+near infrared photometry of KiDS-VIKING and the overlapping spectroscopic data sets. The selection process involved estimating the red sequence redshifts, assessing the purity of the sample and estimating the underlying redshift distributions of redshift bins. After performing the selection, we mitigated the impact of survey properties on the observed number density of galaxies by assigning photometric weights to the galaxies. We measured the angular two-point correlation function of the red galaxies in four redshift bins and constrain the large-scale bias of our red sequence sample assuming a fixed ΛCDM cosmology. We find consistent linear biases for two luminosity-threshold samples (‘dense’ and ‘luminous’). We find that our constraints are well characterised by the passive evolution model.