Protostars and Planets VI, Heidelberg, July 15-20, 2013

Poster 2B002

THERMAL SWEEPING: A RAPID DISC DISPERAL MECHANISM

Owen, James (Canadian Institute for Theoretical Astrophysics)
Hudoba de Badyn, Mathias (University of British Colombia)
Ercolano, Barbara (Excellence Cluster, Munich)
Clarke, Cathie (Insitute of Astronomy, Cambridge)

Abstract:
Mechanisms to clear the gas and dust from protoplanetary discs after a few Myrs of evolution has been a subject of debate for several years. The majority of proposed mechanisms ( e.g. planet formation, grain growth, photoevaporation) suggest that clearing takes longer the further through the disc it proceeds. This is primarily driven by the longer time-scales, and larger amounts of gas and dust to clear as one moves to larger and larger radii in the disc. However, such a prediction does not appear to be backed up by observations with very few transition discs observed with inner holes sizes >50 AU in size. I will present a new clearing mechanism that takes over when disc clearing has proceed to larger radii >50 AU, driven by the deeply penetrating high energy radiation (FUV/X-rays) that can clear the outer disc on much faster ∼ dynamical time-scales.

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