First Light And Reionisation Epoch Simulations (FLARES) II: The
  Photometric Properties of High-Redshift Galaxies
  We present the photometric properties of galaxies in the First Light and
Reionisation Epoch Simulations (FLARES). The simulations trace the evolution of
galaxies in a range of overdensities through the Epoch of Reionistion (EoR).
With a novel weighting scheme we combine these overdensities, extending
significantly the dynamic range of observed composite distribution functions
compared to periodic simulation boxes. FLARES predicts a significantly larger
number of intrinsically bright galaxies, which can be explained through a
simple model linking dust-attenuation to the metal content of the interstellar
medium, using a line-of-sight (LOS) extinction model. With this model we
present the photometric properties of the FLARES galaxies for $z \in [5,10]$.
We show that the ultraviolet (UV) luminosity function (LF) matches the
observations at all redshifts. The function is fit by Schechter and double
power-law forms, with the latter being favoured at these redshifts by the
FLARES composite UV LF. We also present predictions for the UV continuum slope
as well as the attenuation in the UV. The impact of environment on the UV LF is
also explored, with the brightest galaxies forming in the densest environments.
We then present the line luminosity and equivalent widths of some prominent
nebular emission lines arising from the galaxies, finding rough agreement with
available observations. We also look at the relative contribution of obscured
and unobscured star formation, finding comparable contributions at these
redshifts.
