A comparison of young star properties with local galactic environment
  for LEGUS/LITTLE THINGS dwarf irregular galaxies
  We have explored the role environmental factors play in determining
characteristics of young stellar objects in nearby dwarf irregular and Blue
Compact Dwarf galaxies. Star clusters are characterized by concentrations,
masses, and formation rates, OB associations by mass and mass surface density,
O stars by their numbers and near-ultraviolet absolute magnitudes, and HII
regions by Halpha surface brightnesses. These characteristics are compared to
surrounding galactic pressure, stellar mass density, HI surface density, and
star formation rate surface density. We find no trend of cluster
characteristics with environmental properties, implying that larger scale
effects are more important in determining cluster characteristics or that rapid
dynamical evolution erases memory of the initial conditions. On the other hand,
the most massive OB associations are found at higher pressure and HI surface
density, and there is a trend of higher HII region Halpha surface brightness
with higher pressure, suggesting that a higher concentration of massive stars
and gas are found preferentially in regions of higher pressure. At low
pressures we find massive stars but not bound clusters and OB associations. We
do not find evidence for an increase of cluster formation efficiency as a
function of star formation rate density. However, there is an increase in the
ratio of the number of clusters to number of O stars with pressure, perhaps
reflecting an increase in clustering properties with star formation rate.
