Nuria CALVET : University of Michigan
Protoplanetary disk evolution and clearing
Protoplanetary disks evolve from primeval optically thick, mostly gaseous structures to debris disks in which the major constituent is dust. I will review what we have learned in recent years about the initial stages of this evolution, mostly from Spitzer data. In particular, I will explain how present evidence seems to indicate that disks evolve decreasing their mass and mass accretion rate while dust growths and settles toward the midplane, in rough agreement with viscous and dust evolution theories. However, at some point this evolution pattern is disrupted rapidly, the inner disk regions are cleared out, and the disk appears as a transition disk. I will then discuss the theories that have been presented so far to explain these transition disks, and compare their predictions to observational constraints.Last modified: Sun Jul 9 17:30:31 2006