Stellar winds and photoionization in a spiral arm
  The role of different stellar feedback mechanisms in giant molecular clouds
is not well understood. This is especially true for regions with many
interacting clouds as would be found in a galactic spiral arm. In this paper,
building on previous work by Bending et al., we extract a
$500\times500\times100$ pc section of a spiral arm from a galaxy simulation. We
use smoothed particle hydrodynamics (SPH) to re-simulate the region at higher
resolution (1 M$_\odot$ per particle). We present a method for momentum-driven
stellar winds from main sequence massive stars, and include this with
photoionization, self-gravity, a galactic potential, and ISM heating/cooling.
We also include cluster-sink particles with accretion radii of 0.78 pc to track
star/cluster formation. The feedback methods are as robust as previous models
on individual cloud scales (e.g. Dale et al.). We find that photoionization
dominates the disruption of the spiral arm section, with stellar winds only
producing small cavities (at most $\sim$ 30 pc). Stellar winds do not affect
the resulting cloud statistics or the integrated star formation
rate/efficiency, unlike ionization, which produces more stars, and more clouds
of higher density and higher velocity dispersion compared to the control run
without feedback. Winds do affect the sink properties, distributing star
formation over more low-mass sinks ($\sim 10^2$ M$_\odot$) and producing fewer
high-mass sinks ($\sim 10^3$ M$_\odot$). Overall, stellar winds play at best a
secondary role compared to photoionization, and on many measures, they have a
negligible impact.
