The growth of disks and bulges during hierarchical galaxy formation. II:
  metallicity, stellar populations and dynamical evolution
  We investigate the properties of the stellar populations of model galaxies as
a function of galaxy evolutionary history and angular momentum content. We use
the new semi-analytic model presented in Tonini et al. (2016). This new model
follows the angular momentum evolution of gas and stars, providing the base for
a new star formation recipe, and treatment of the effects of mergers that
depends on the central galaxy dynamical structure. We find that the new recipes
have the effect of boosting the efficiency of the baryonic cycle in producing
and recycling metals, as well as preventing minor mergers from diluting the
metallicity of bulges and ellipticals. The model reproduces the stellar mass -
stellar metallicity relation for galaxies above 1e10 solar masses, including
Brightest Cluster Galaxies. Model disks, galaxies dominated by
instability-driven components, and merger-driven objects each stem from
different evolutionary channels. These model galaxies therefore occupy
different loci in the galaxy mass-size relation, which we find to be in accord
with the Atlas 3D classification of disk galaxies, fast rotators and slow
rotators. We find that the stellar populations' properties depend on the galaxy
evolutionary type, with more evolved stellar populations being part of systems
that have lost or dissipated more angular momentum during their assembly
history.
