Bruno Henriques - October 30, 2015

A self-consistent model of galaxy formation across cosmic time

I will present results from a recent major release of the Munich
model of galaxy formation: the henriques2015 model. In this
version we have updated the cosmology of the simulation to the
Planck first-year results, while modifying the treatment of baryonic
processes to reproduce recent data on the abundance and passive
fractions of galaxies from z = 3 down to z = 0. Matching these
more extensive and more precise observational results requires us
to delay the reincorporation of wind ejecta, to lower the surface
density threshold for turning cold gas into stars, to eliminate
ram-pressure stripping in haloes less massive than 10^14 Msun,
and to modify our model for radio mode feedback.

These changes cure the most obvious failings of our previous models,
namely the overly early formation of low-mass galaxies and the overly
large fraction of them that are passive at late times. Massive
galaxies (log M*/Msun > 11.0) assemble most of their mass before z = 1
and are predominantly old and passive at z = 0, while lower mass
galaxies assemble later and, for log M*/Msun < 9.5, are still
predominantly blue and star forming at z = 0. This phenomenological
but physically based model allows the observations to be interpreted
in terms of the efficiency of the various processes that control the
formation and evolution of galaxies as a function of their stellar
mass, gas content, environment and time.