Non-equilibrium Ionization States Within Galactic Outflows: Explaining
  Their O VI and N V Column Densities
  We present a suite of one-dimensional spherically-symmetric hydrodynamic
simulations that study the atomic ionization structure of galactic outflows. We
track the ionization state of the outflowing gas with a non-equilibrium atomic
chemistry network that includes photoionization, photo-heating, and ion-by-ion
cooling. Each simulation describes a steady-state outflow that is defined by
its mass and energy input rates, sonic radius, metallicity, and UV flux from
both the host galaxy and meta-galactic background. We find that for a large
range of parameter choices, the ionization state of the material departs
strongly from what it would be in photo-ionization equilibrium, in conflict
with what is commonly assumed in the analysis of observations. In addition,
nearly all the models reproduce the low N V to O VI column density ratios and
the relatively high O VI column densities that are observed.
