Submillimeter View of Gas and Dust in the Forming Super Star Cluster in NGC 5253 (1509.08531v1)

Abstract: A giant molecular cloud has been detected surrounding the supernebula in NGC 5253, revealing details of the formation and feedback process in a very massive star cluster. "Cloud D" was recently mapped in CO J=3-2 with the Submillimeter Array. The cloud surrounds a currently forming massive cluster of mass ~10$^6$ $\rm M_\odot$ and luminosity ~10$^9$ $\rm L_\odot$. Cloud D is hot, clearly associated with the cluster, yet kinematically relatively quiescent. The dust mass is ~15,000 $\rm M_\odot$, giving a gas-to-dust ratio of ~50, nearly an order of magnitude lower than expected for this low metallicity galaxy. We posit that enrichment by the cluster, leading to a stalled cluster wind, has created the unusual conditions in Cloud D. The absence of current mechanical impact of the young cluster on the cloud, in spite of the presence of thousands of O stars, may permit future generations of stars to form near the massive cluster.