"Observing and Analyzing" Images From a Simulated High Redshift Universe
  We investigate the high-redshift evolution of the restframe UV-luminosity
function (LF) of galaxies via hydrodynamical cosmological simulations, coupled
with an emulated observational astronomy pipeline that provides a direct
comparison with observations. We do this by creating mock images and synthetic
galaxy catalogs of approximately 100 square arcminute fields from the numerical
model at redshifts ~ 4.5 to 10.4. We include the effects of dust extinction and
the point spread function (PSF) for the Hubble WFC3 camera for comparison with
space observations. We also include the expected zodiacal background to predict
its effect on space observations, including future missions such as the James
Webb Space Telescope (JWST). When our model catalogs are fitted to Schechter
function parameters, we predict that the faint-end slope alpha of the LF
evolves as alpha = -1.16 - 0.12 z over the redshift range z ~ 4.5 to 7.7, in
excellent agreement with observations from e.g., Hathi et al. (2010). However,
for redshifts z ~ 6 to 10.4, alpha(z) appears to display a shallower evolution,
alpha = -1.79 - 0.03 z. Augmenting the simulations with more detailed physics -
specifically stellar winds and supernovae (SN) - produces similar results. The
model shows an overproduction of galaxies, especially at faint magnitudes,
compared with the observations, although the discrepancy is reduced when dust
extinction is taken into account.
