GMC Evolution in a Barred Spiral Galaxy with Star Formation and Thermal
  Feedback
  We explore the impact of star formation and thermal stellar feedback on the
giant molecular cloud (GMC) population forming in a M83-type barred spiral
galaxy. We compare three high-resolution simulations (1.5 pc cell size) with
different star formation/feedback models: one with no star formation, one with
star formation but no feedback, and one with star formation and thermal energy
injection. We analyze the resulting population of clouds, finding that we can
identify the same population of massive, virialized clouds and transient,
low-surface density clouds found in our previous work (that did not include
star formation or feedback). Star formation and feedback can affect the mix of
clouds we identify. In particular, star formation alone simply converts dense
cloud gas into stars with only a small change to the cloud populations,
principally resulting in a slight decrease in the transient population.
Feedback, however, has a stronger impact: while it is not generally sufficient
to entirely destroy the clouds, it does eject gas out of them, increasing the
gas density in the inter-cloud region. This decreases the number of massive
clouds, but substantially increases the transient cloud population. We also
find that feedback tends to drive a net radial inflow of massive clouds,
leading to an increase in the star formation rate in the bar region. We examine
a number of possible reasons for this and conclude that it is possible that the
drag force from the enhanced intercloud density could be responsible.
