  We demonstrate that massive simulated galaxies assemble in two phases, with
the initial growth dominated by compact in situ star formation, whereas the
late growth is dominated by accretion of old stars formed in subunits outside
the main galaxy. We also show that 1) gravitational feedback strongly
suppresses late star formation in massive galaxies contributing to the observed
galaxy colour bimodality that 2) the observed galaxy downsizing can be
explained naturally in the two-phased model and finally that 3) the details of
the assembly histories of massive galaxies are directly connected to their
observed kinematic properties.
