Initial conditions within a massive, Arches-like protocluster

Stellar clusters are the building blocks of galaxies and the nurseries of most stellar systems. However, little is known about the formation of the most massive clusters. In our recent MALT90 and HOPS surveys, one object, G0.25+0.16, stands out as extreme. Identified as a cold, dense, massive molecular clump devoid of current star-formation, it has exactly the properties expected for a clump that may form an Arches-like cluster. Our wealth of ancillary data reveals tantalizing evidence that it is highly structured and, thus, may be undergoing hierarchical fragmentation. Here we propose to observe the cold, dense gas from this unique proto-cluster. The proposed ATCA NH3 and NH2D observations will reveal the small-scale temperature distribution and kinematics of the cold, dense gas. These data combined with our upcoming ALMA early science observations of the cold dust toward this clump will allow us to reliably probe the initial conditions within this massive, Arches-like protocluster.