EPoS Contribution
EPoS Contribution
Constraining Conditions of Cluster Formation: Paving the Way for the ALMA age

Sarah Ragan
University of Michigan, Ann Arbor, Michigan, USA
Infrared dark clouds (IRDCs) are coming into focus as the progenitors of massive stars and clusters, though their study has been limited to date because of their great distance from us. We present the findings of our on-going effort to provide a detailed characterization of IRDCs that maximizes the power of our current observational capabilities. We examine IRDCs in dust absorption using Spitzer, characterize the fragmenting structure with 2'' resolution, effectively probing at sub-parsec scales, and find a mass function slope that is shallower than analogous studies in dust emission. In addition, we supplement these Spitzer results with VLA and CARMA observations of high-density gas tracers (e.g. NH3 and N2H+) that provide kinematic and chemical information with very high spectral resolution (~0.2km/s) and on similar spatial scales. These studies lay the necessary foundation for an emerging field and will guide future EVLA and ALMA observers in a new age of observational maturity, allowing us to bring infrared dark clouds to the frontier of star formation studies. We will discuss how these instruments of the future will probe the internal structure of pre- and proto-stellar clumps and cores and strengthen constraints on theoretical models of proto-cluster structure by more than an order of magnitude.