Non-equilibrium Photoionization and Hydrodynamic Simulations of
  Starburst-driven Outflows
  Starburst-driven galactic outflows in star-forming galaxies have been
observed to contain complex thermal structures and emission line features that
are difficult to explain by adiabatic fluid models and plasmas in
photoionization equilibrium (PIE) and collisional ionization equilibrium (CIE).
We previously performed hydrodynamic simulations of starburst-driven outflows
using the MAIHEM module for non-equilibrium atomic chemistry and radiative
cooling functions in the hydrodynamics code FLASH, and calculated emission
lines in combined CIE and PIE conditions. In the present study, we consider
time-dependent non-equilibrium ionization (NEI) states produced by our MAIHEM
simulations. Through extensive CLOUDY calculations made with the NEI states
from our hydrodynamic simulations, we predict the UV and optical emission line
profiles for starburst-driven outflows in time-evolving non-equilibrium
photoionization conditions. Our hydrodynamic results demonstrate applications
of non-equilibrium radiative cooling for H II regions in starburst galaxies
hosting cool outflows.
