KiDS+GAMA: The weak lensing calibrated stellar-to-halo mass relation of central and satellite galaxies

Authors: Andrej Dvornik, Henk Hoekstra, Konrad Kuijken, Angus H. Wright, Marika Asgari, Maciej Bilicki, Thomas Erben, Benjamin Giblin, Alister W. Graham, Catherine Heymans, Hendrik Hildebrandt, Andrew M. Hopkins, Arun Kannawadi, Chieh-An Lin, Edward N. Taylor, Tilman Trooster

Abstract: We simultaneously present constraints on the stellar-to-halo mass relation for central and satellite galaxies through a weak lensing analysis of spectroscopically classified galaxies. Using overlapping data from the 4th data release of the Kilo-Degree Survey (KiDS), and the Galaxy And Mass Assembly survey (GAMA), we find that satellite galaxies are hosted by halo masses that are 0.53±0.39 dex (68 percent confidence, 3-sigma detection) smaller than those of central galaxies of the same stellar mass (for a stellar mass of log(M*/MSun) = 10.6). This is consistent with galaxy formation models, whereby infalling satellite galaxies are preferentially stripped of their dark matter. We find consistent results with similar uncertainties when comparing constraints from a standard azimuthally averaged galaxy-galaxy lensing analysis and a two-dimensional likelihood analysis of the full shear field. As the latter approach is somewhat biased due to the lens incompleteness, and does not provide any improvement in precision when applied to actual data, we conclude that stacked tangential shear measurements are best-suited for studies of the galaxy-halo connection.