  We examine ultraviolet halos around a sample of highly inclined galaxies
within 25 Mpc to measure their morphology and luminosity. Despite contamination
from galactic light scattered into the wings of the point-spread function, we
find that UV halos occur around each galaxy in our sample. Around most galaxies
the halos form a thick, diffuse disk-like structure, but starburst galaxies
with galactic superwinds have qualitatively different halos that are more
extensive and have filamentary structure. The spatial coincidence of the UV
halos above star-forming regions, the lack of consistent association with
outflows or extraplanar ionized gas, and the strong correlation between the
halo and galaxy UV luminosity suggest that the UV light is an extragalactic
reflection nebula. UV halos may thus represent 1-10 million solar masses of
dust within 2-10 kpc of the disk, whose properties may change with height in
starburst galaxies.
