  We present new multi-configuration HI aperture synthesis imaging of the
nearby dwarf starburst galaxy NGC 625 obtained with the Australia Telescope
Compact Array. Total HI column density images show gas well-aligned with the
optical major axis, and low-column density HI extending to > 6 optical scale
lengths. The HI velocity field, on the other hand, is highly disturbed, with
neutral gas at nearly all detected velocities within the central region. After
considering various interpretations, we find that a blowout scenario most
accurately describes the data. Since at our resolution we do not detect any
large evacuated holes in the HI disk, we interpret this blowout to be the
result of the extended (both spatially and temporally) star formation event
which NGC 625 has undergone in the last 100 Myr. This is one of the clearest
examples of HI outflow detected in a dwarf galaxy. We find no obvious external
trigger for this extended star formation event. We detect strong radio
continuum emission from the largest HII regions; comparing to our HST and
ground-based H Alpha fluxes suggests either appreciable amounts of extinction
toward the star formation regions, or the contribution of non-thermal sources
to the radio continuum luminosity.

Astrophysics