Stellar Clusters in M83: Formation, evolution, disruption and the
  influence of environment
  We study the stellar cluster population in two adjacent fields in the nearby,
face-on spiral galaxy, M83, using WFC3/HST imaging. The clusters are selected
through visual inspection to be centrally concentrated, symmetric, and resolved
on the images, which allows us to differentiate between clusters and likely
unbound associations. We compare our sample with previous studies and show that
the differences between the catalogues are largely due to the inclusion of
large numbers of diffuse associations within previous catalogues. The
luminosity function of the clusters is well approximated by a power-law with
index, -2, over most of the observed range, however a steepening is seen at M_V
= -9.3 and -8.8 in the inner and outer fields, respectively. Additionally, we
show that the cluster population is inconsistent with a pure power-law mass
distribution, but instead exhibits a truncation at the high mass end. If
described as a Schechter function, the characteristic mass is 1.6 and 0.5 *
10^5 Msun, for the inner and outer fields, respectively, in agreement with
previous estimates of other cluster populations in spiral galaxies. Comparing
the predictions of the mass independent disruption (MID) and mass dependent
disruption (MDD) scenarios with the observed distributions, we find that both
models can accurately fit the data. However, for the MID case, the fraction of
clusters destroyed (or mass lost) per decade in age is dependent on the
environment, hence, the age/mass distributions of clusters are not universal.
In the MDD case, the disruption timescale scales with galactocentric distance
(being longer in the outer regions of the galaxy) in agreement with analytic
and numerical predictions. Finally, we discuss the implications of our results
on other extragalactic surveys, focussing on the fraction of stars that form in
clusters and the need (or lack thereof) for infant mortality.
