Modeling the Tenuous Intracluster Medium in Globular Clusters

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 mass supply from the evolved stellar population and energy injection from the main sequence stellar members for globular clusters 47 Tucanae, M15, NGC 6440, and NGC 6752. Disregarding all other gas evacuation processes, we find that the energy output from the main sequence stellar population alone is capable of effectively clearing the evolved stellar ejecta and producing intracluster gas densities consistent with current observational constraints. This result distinguishes a viable ubiquitous gas and dust evacuation mechanism for 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 cluster 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.