Updated results on the galaxy–halo connection from satellite kinematics in SDSS

Abstract

ABSTRACT We present new results on the relationship between central galaxies and dark matter haloes inferred from observations of galaxy abundances and satellite kinematics in the Sloan Digital Sky Survey (SDSS) DR7. We employ an updated analysis framework that includes detailed mock catalogues to model observational effects in SDSS. Our results constrain the colour-dependent conditional luminosity function of dark matter haloes, as well as the radial profile of satellite galaxies. Confirming previous results, we find that red central galaxies live in more massive haloes than blue galaxies at a fixed luminosity. Additionally, our results suggest that satellite galaxies have a radial profile less centrally concentrated than dark matter but not as cored as resolved subhaloes in dark-matter-only simulations. Compared to previous works using satellite kinematics by More et al., we find much more competitive constraints on the galaxy–halo connection, on par with those derived from a combination of galaxy clustering and galaxy–galaxy lensing. This improvement stems from also modelling the abundance of galaxies as well as a larger sample size and more realistic observational uncertainties. We compare our results on the galaxy–halo connection to other studies using galaxy clustering and group catalogues, showing a reasonable agreement between these different techniques. We discuss future applications of satellite kinematics in the context of constraining cosmology and the relationship between galaxies and dark matter haloes.