Surviving gas expulsion with substructure

We investigate the reaction of clumpy stellar distributions to gas expulsion. We show that regions containing highly unbound substructures/subclusters after gas expulsion can produce a significant final bound cluster. The key quantity in determining if a region is able to form a bound cluster is the global virial ratio, and so regions must be looked at as a whole rather than by individual substructure/subclusters when determining if they might survive as a bound cluster.