From discs to planetesimals I: evolution of gas and dust discs

Abstract

I review the processes that shape the evolution of protoplanetary discs around young, solar-mass stars. I first discuss observations of protoplanetary discs, and note in particular the constraints these observations place on models of disc evolution. The processes that affect the evolution of gas discs are then discussed, with the focus in particular on viscous accretion and photoevaporation, and recent models which combine the two. I then discuss the dynamics and growth of dust grains in discs, considering models of grain growth, the gas-grain interaction and planetesimal formation, and review recent research in this area. Lastly, I consider the so-called "transitional" discs, which are thought to be observed during disc dispersal. Recent observations and models of these systems are reviewed, and prospects for using statistical surveys to distinguish between the various proposed models are discussed.Comment: 28 pages, 9 figures. Refereed review chapter for proceedings of VLTI summer school on "Circumstellar discs and planets at very high angular resolution", to appear in New Astronomy Reviews. See http://www.vlti.org/ for more detail