Galaxy formation in the PLANCK cosmology - III. The high-redshift
  universe
  We present high-redshift predictions of the star-formation-rate distribution
function (SFR DF), UV luminosity function (UV LF), galactic stellar mass
function (GSMF), and specific star-formation rates (sSFRs) of galaxies from the
latest version of the Munich semi-analytic model L-Galaxies. We find a good fit
to both the shape and normalisation of the SFR DF at $z=4-7$, apart from a
slight under-prediction at the low SFR end at $z=4$. Likewise, we find a good
fit to the faint number counts for the observed UV LF; at brighter magnitudes
our predictions lie below the observations, increasingly so at higher
redshifts. At all redshifts and magnitudes, the raw (unattenuated) number
counts for the UV LF lie above the observations. Because of the good agreement
with the SFR we interpret our under-prediction as an over-estimate of the
amount of dust in the model for the brightest galaxies, especially at
high-redshift. While the shape of our GSMF matches that of the observations, we
lie between (conflicting) observations at $z=4-5$, and under-predict at
$z=6-7$. The sSFRs of our model galaxies show the observed trend of increasing
normalisation with redshift, but do not reproduce the observed mass dependence.
Overall, we conclude that the latest version of L-Galaxies, which is tuned to
match observations at $z\leq3$, does a fair job of reproducing the observed
properties of galaxies at $z\geq4$. More work needs to be done on understanding
observational bias at high-redshift, and upon the dust model, before strong
conclusions can be drawn on how to interpret remaining discrepancies between
the model and observations.
