Simulating galaxy evolution with a non-universal stellar initial mass
  function
  We consider that the stellar initial mass function (IMF) depends on physical
properties of star-forming molecular clouds in galaxies and thereby investigate
how such a non-universal IMF (NUIMF) influences galaxy evolution. We
incorporate a NUIMF model into galaxy-scale chemodynamical simulations in order
to investigate the differences in chemical and dynamical evolution of disk
galaxies between the NUIMF and universal IMF (UIMF) models. In the adopted
NUIMF model, the three slopes of the Kroupa IMF depend independently on
densities and metallicities ([Fe/H]) of molecular gas clouds, and production
rates of metals and dust from massive and AGB stars can vary according to the
time evolution of the three IMF slopes. The preliminary results of the
simulations are as follows. Star formation rates in actively star-forming disk
galaxies can be significantly lower in the NUIMF model than in the UIMF model,
and the differences between the two models can be more remarkable in galaxies
with higher SFRs. Chemical enrichment can proceed more rapidly in the NUIMF
model and [Mg/Fe] for a given metallicity is higher in the NUIMF model. The
evolution of H2 fraction (f_H2) and dust-to-gas ratio (D) is more rapid in the
NUIMF model so that the final f_H2 and $D$ can be higher in the NUIMF model.
Formation of massive stellar clumps in gas-rich disks is more strongly
suppressed owing to the stronger SN feedback effect in the NUIMF model. The
radial density profiles of new stars within the central 1kpc are shallower in
the NUIMF model.
