Richard ALEXANDER : JILA, University of Colorado
Dynamic models of disc clearing
I review recent developments in the modelling of disc evolution and dispersal. I discuss the observational constraints of models of disc evolution, noting in particular the evolutionary timescales demanded by the data. Recent work has resulted in a number of improvements to models of disc photoevaporation, and I present recent work which combines photoevaporation of the disc by the central star with viscous evolution. I compare the predictions of such models with observations of nearby star-forming regions such as Taurus-Auriga, and show that the models are consistent with the data across a wide range in wavelength, from near-infrared to millimetre wavelengths. I also consider recent observations of so-called "transitional" discs, and discuss the successes and failures of different models in the transitional regime. Photoevaporation, dust evolution and the influence of planets can all play a role in this phase of disc evolution, and I compare the predictions of these various models with recent observations. I conclude by presenting a tentative evolutionary scenario covering the entire lifetime of protoplanetary discs, and by discussing future prospects for the study of disc evolution.Last modified: Sun Jul 9 17:25:50 2006