Joint galaxy-galaxy lensing and clustering constraints on galaxy formation

We compare predictions for galaxy-galaxy lensing profiles and clustering from the Henriques et al. public version of the Munich semi-analytical model (SAM) of galaxy formation and the IllustrisTNG suite, primarily TNG300, with observations from KiDS + GAMA and SDSS-DR7 using four different selection functions for the lenses (stellar mass, stellar mass and group membership, stellar mass and isolation criteria, and stellar mass and colour). We find that this version of the SAM does not agree well with the current data for stellar mass-only lenses with M-* > 10(11) M-circle dot. By decreasing the merger time for satellite galaxies as well as reducing the radio-mode active galactic nucleus accretion efficiency in the SAM, we obtain better agreement, both for the lensing and the clustering, at the high-mass end. We show that the new model is consistent with the signals for central galaxies presented in Velliscig et al. Turning to the hydrodynamical simulation, TNG300 produces good lensing predictions, both for stellar mass-only (chi(2) = 1.81 compared to chi(2) = 7.79 for the SAM) and locally brightest galaxy samples (chi(2) = 3.80 compared to chi(2) = 5.01). With added dust corrections to the colours it matches the SDSS clustering signal well for red low-mass galaxies. We find that both the SAMs and TNG300 predict similar to 50 per cent excessive lensing signals for intermediate-mass red galaxies with 10.2 < log(10)M(*)[M-circle dot] < 11.2 at r approximate to 0.6 h(-1) Mpc, which require further theoretical development.