Photoionization analysis of chemo-dynamical dwarf galaxies simulations
  Photoionization modelling allows to follow the transport, the emergence, and
the absorption of photons taking into account all important processes in
nebular plasmas. Such modelling needs the spatial distribution of density,
chemical abundances and temperature, that can be provided by chemo-dynamical
simulations (ChDS) of dwarf galaxies. We perform multicomponent photoionization
modelling (MPhM) of the ionized gas using 2-D ChDSs of dwarf galaxies. We
calculate emissivity maps for important nebular emission lines. Their
intensities are used to derive the chemical abundance of oxygen by the
so-called Te- and R23-methods. Some disagreements are found between oxygen
abundances calculated with these methods and the ones coming from the ChDSs. We
investigate the fraction of ionizing radiation emitted in the star-forming
region which is able to leak out the galaxy. The time- and direction-averaged
escape fraction in our simulation is 0.35-0.4. Finally, we have calculated the
total Halpha lumi- nosity of our model galaxy using Kennicutt's calibration to
derive the star-formation rate. This value has been compared to the 'true' rate
in the ChDSs. The Halpha-based star-formation rate agrees with the true one
only at the beginning of the simulation. Minor deviations arise later on and
are due in part to the production of high-energy photons in the warm-hot gas,
in part to the leakage of energetic photons out of the galaxy. The effect of
artificially introduced thin dense shells (with thicknesses smaller than the
ChDSs spatial resolution) is investigated, as well.
