Dust evolution in zoom-in cosmological simulations of galaxy formation
  We present cosmological zoom-in hydro-dynamical simulations for the formation
of disc galaxies, implementing dust evolution and dust promoted cooling of hot
gas. We couple an improved version of our previous treatment of dust evolution,
which adopts the two-size approximation to estimate the grain size
distribution, with the MUPPI star formation and feedback sub-resolution model.
Our dust evolution model follows carbon and silicate dust separately. To
distinguish differences induced by the chaotic behaviour of simulations from
those genuinely due to different simulation set-up, we run each model six
times, after introducing tiny perturbations in the initial conditions. With
this method, we discuss the role of various dust-related physical processes and
the effect of a few possible approximations adopted in the literature.
  Metal depletion and dust cooling affect the evolution of the system, causing
substantial variations in its stellar, gas and dust content. We discuss
possible effects on the Spectral Energy Distribution of the significant
variations of the size distribution and chemical composition of grains, as
predicted by our simulations during the evolution of the galaxy. We compare
dust surface density, dust-to-gas ratio and small-to-big grain mass ratio as a
function of galaxy radius and gas metallicity predicted by our fiducial run
with recent observational estimates for three disc galaxies of different
masses. The general agreement is good, in particular taking into account that
we have not adjusted our model for this purpose.
