Planet-forming Disks Around Young Stars

Direct observations of the reservoirs of planet-building material - the disks around young stars - play a critical role in developing theoretical models of the planet formation process. I will present state-of-the-art high angular resolution Submillimeter Array (SMA) observations designed to provide new insight into the spatial distribution of mass in young protoplanetary disks. Based on these SMA data and a suite of ground- and spaced-based observations, we have developed a radiative transfer modeling toolkit that can be used to derive the temperature and density structures for a given disk. The results are being used to characterize some of the key disk evolution processes and to estimate the likelihood of future planet formation in these systems. In fact, a growing sample of disks exhibit compelling evidence that the planet formation process has gotten a head start. I will highlight some exciting new observations that resolve low-density disk cavities on Solar System size-scales and discuss how these may prove to be the signposts of very young (1 Myr) planetary systems. Along the way, I will comment on how this work foreshadows what we expect from next-generation instruments in this field, in particular from the ALMA project starting in 2012.