The role of gas in debris disks
Alexis Brandeker
Stockholm Observatory

Debris disks are believed to be the products of colliding planetesimals, remnants from the planet formation process. In contrast to the protoplanetary disks, the debris disks are gas poor. They are not completely devoid of gas, however, a discovery that has been a rich source of puzzlement and speculation. Some of the questions that arise are: Where does the gas come from and what keeps it from blowing away by the stellar radiation pressure? Solving these questions have the potential to shed light on the chemical composition of the building blocks of planets, the planetesimals. Another potentially important effect of the gas is inducing structure into the dust disk through gas-dust interactions, possibly mimicking planetary herding of the dust and putting into question inferences of exoplanets from disk structure alone. A recent example that will be discussed is that of Fomalhaut.

Date:	Jeudi, 26 septembre 2013
Time:	11:30
Where:	Université de Montréal
	Pavillon Roger-Gaudry, local D-460
Contact:	Lison Malo