TAP Colloquium

Monday, Apr 7, 2014
4:00 pm — 5:00 pm

Location: Steward Observatory
Room: N210

James Owen
Canadian Institute for Theoretical Astrophysics

Evolution and Dispersal of Protoplanetary Discs

Abstract:
I will discuss the evolution of protoplanetary discs, the discs which provide the reservoirs of gas and dust from which planets form. I will argue that the observations of protoplanetary disc evolution dictate that they follow a "two-timescale" evolution. Where the discs behave as normal viscous accretion discs for most of their lifetimes, before being rapidly destroyed. I will discuss the favoured "photoevaporative-switch" model, which quantitatively reproduces this evolutionary time-scale, as well as other characteristics of disc evolution. I will then discuss the details of the two possible photoevaporation models: EUV driven & X-ray driven, describing their different properties and implications for disc evolution. Finally, I will focus on direct observational probes of the photoevaporative winds themselves and discuss the possibility of finally directly probing the mass-loss rates of photoevaporative winds from protoplanetary discs.

Host: Bill Hubbard
TAP Colloquia