Star Formation in Disk Galaxies. III. Does stellar feedback result in
  cloud death?
  Stellar feedback, star formation and gravitational interactions are major
controlling forces in the evolution of Giant Molecular Clouds (GMCs). To
explore their relative roles, we examine the properties and evolution of GMCs
forming in an isolated galactic disk simulation that includes both localised
thermal feedback and photoelectric heating. The results are compared with the
three previous simulations in this series which consists of a model with no
star formation, star formation but no form of feedback and star formation with
photoelectric heating in a set with steadily increasing physical effects. We
find that the addition of localised thermal feedback greatly suppresses star
formation but does not destroy the surrounding GMC, giving cloud properties
closely resembling the run in which no stellar physics is included. The
outflows from the feedback reduce the mass of the cloud but do not destroy it,
allowing the cloud to survive its stellar children. This suggests that weak
thermal feedback such as the lower bound expected for supernova may play a
relatively minor role in the galactic structure of quiescent Milky Way-type
galaxies, compared to gravitational interactions and disk shear.
