Starburst-Driven Galactic Winds: Filament Formation and Emission
  Processes
  We have performed a series of three-dimensional simulations of the
interaction of a supersonic wind with a non-spherical radiative cloud. These
simulations are motivated by our recent three-dimensional model of a
starburst-driven galactic wind interacting with an inhomogeneous disk, which
show that an optically emitting filament can be formed by the break-up and
acceleration of a cloud into a supersonic wind. In this study we consider the
evolution of a cloud with two different geometries (fractal and spherical) and
investigate the importance of radiative cooling on the cloud's survival. We
have also undertaken a comprehensive resolution study in order to ascertain the
effect of the assumed numerical resolution on the results. We find that the
ability of the cloud to radiate heat is crucial for its survival. While an
adiabatic cloud is destroyed over a short period of time, a radiative cloud is
broken up via the Kelvin-Helmholtz instability into numerous small, dense
cloudlets, which are drawn into the flow to form a filamentary structure. The
degree of fragmentation is highly dependent on the resolution of the
simulation, with the number of cloudlets formed increasing as the
Kelvin-Helmholtz instability is better resolved. Nevertheless, there is a clear
qualitative trend, with the filamentary structure still persistent at high
resolution. We confirm the mechanism behind the formation of the H-alpha
emitting filaments found in our global simulations of a starburst-driven wind.
Based on our resolution study, we conclude that bow shocks around accelerated
gas clouds, and their interaction, are the main source of the soft X-ray
emission observed in these galactic-scale winds. [ABRIDGED]
