"Observations" of simulated dwarf galaxies: Star-formation histories
  from color-magnitude diagrams
  Apparent deviations between properties of dwarf galaxies from observations
and simulations are known to exist, such as the "Missing Dwarfs" problem, the
too-big-to-fail problem, and the cusp-core problem, to name a few. Recent
studies have shown that these issues can at least be partially resolved by
taking into account the systematic differences between simulations and
observations. This work aims to investigate and address any systematic
differences affecting the comparison of simulations with observations. To this
aim, we analyzed a set of 24 realistically simulated MoRIA (Models of Realistic
dwarfs In Action) dwarf galaxies in an observationally motivated way. We first
constructed "observed" color-magnitude diagrams (CMDs) of the simulated dwarf
galaxies in the typically used V- and I-bands. Then we used the CMD-fitting
method to recover their star-formation histories (SFHs) from their observed
CMDs. These solved SFHs were then directly compared to the true SFHs from the
simulation star-particle data, mainly in terms of the star-formation rate(SFR)
and the age-metallicity relation (AMR). We applied a dust extinction
prescription to the simulation data to produce observed CMDs affected by dust
in star-formation regions. Since future facilities, such as the JWST and E-ELT
will focus on the near IR rather than the optical, we also constructed and
analyzed CMDs using the I- and H-bands. We find a very good agreement between
the recovered and the true SFHs of all the simulated dwarf galaxies in our
sample, from the synthetic CMD analysis of their V-I versus I as well as the
I-H versus H CMDs. Dust leads to an underestimation of the SFR during the last
few hundred million years. Overall, our analysis indicates that quantities like
SFR and AMR derived from the photometric observations of galaxies are directly
comparable to their simulated counterparts.
