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 fourth 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% confidence, 3σ detection) smaller than those of central galaxies of the same stellar mass (for a stellar mass of log(M⋆ /M⊙ ) = 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 as it does not provide any improvement to the precision when applied to actual data, we conclude that stacked tangential shear measurements are best-suited for studies of the galaxy-halo connection.
Bibliographical noteReproduced with permission from Astronomy & Astrophysics, Copyright ESO 2020. First published in Astronomy and Astrophysics, 642, A83, 2020, published by EDP Sciences. The original publication is available at https://doi.org/10.1051/0004-6361/202038693. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.
- gravitational lensing: weak
- methods: statistical
- galaxies: halos
- large-scale structure of Universe
- dark matter