Galaxy and Mass Assembly: luminosity and stellar mass functions in GAMA
  groups
  How do galaxy properties (such as stellar mass, luminosity, star formation
rate, and morphology) and their evolution depend on the mass of their host dark
matter halo? Using the Galaxy and Mass Assembly (GAMA) group catalogue, we
address this question by exploring the dependence on host halo mass of the
luminosity function (LF) and stellar mass function (SMF) for grouped galaxies
subdivided by colour, morphology and central/satellite. We find that spheroidal
galaxies in particular dominate the bright and massive ends of the LF and SMF,
respectively. More massive haloes host more massive and more luminous central
galaxies. The satellite LF and SMF respectively show a systematic brightening
of characteristic magnitude, and increase in characteristic mass, with
increasing halo mass. In contrast to some previous results, the faint-end and
low-mass slopes show little systematic dependence on halo mass. Semi-analytic
models and simulations show similar or enhanced dependence of central mass and
luminosity on halo mass. Faint and low-mass simulated satellite galaxies are
remarkably independent of halo mass, but the most massive satellites are more
common in more massive groups. In the first investigation of low-redshift LF
and SMF evolution in group environments, we find that the red/blue ratio of
galaxies in groups has increased since redshift $z \approx 0.3$ relative to the
field population. This observation strongly suggests that quenching of star
formation in galaxies as they are accreted into galaxy groups is a significant
and ongoing process.
