Modeling Gas Evacuation Mechanisms in Present-Day Globular Clusters:
  Stellar Winds from Evolved Stars and Pulsar Heating
  We employ hydrodynamical simulations to investigate the underlying mechanism
responsible for the low levels of gas and dust in globular clusters. Our models
examine the competing effects of energy and mass supply from the various
components of the evolved stellar population for globular clusters 47 Tucanae,
M15, NGC 6440, and NGC 6752. Ignoring all other gas evacuation processes, we
find that the energy output from the stars that have recently turned off the
main sequence are capable of effectively clearing the evolved stellar ejecta
and producing intracluster gas densities consistent with current observational
constraints. This result distinguishes a viable gas and dust evacuation
mechanism that is ubiquitous in globular clusters. In addition, we extend our
analysis to probe the efficiency of pulsar wind feedback in globular clusters.
The detection of intracluster ionized gas in 47~Tucanae allows us to place
particularly strict limits on pulsar wind thermalization efficiency, which must
be extremely low in the cluster's core in order to be in accordance with the
observed density constraints.
