Robert Harris Thesis Presentation: Protoplanetary Disks in Multiple Star Systems.


Tuesday, August 27, 2013, 11:00am to 12:15pm

See also: PhD Colloquium


Phillips Auditorium

The title of his presentation is Protoplanetary Disks in Multiple Star Systems.


Most stars are born in multiple systems.  Because of this ubiquity, planets in these systems could comprise a large fraction of all planets.  Theory indicates that stellar companions reduce the likelihood of planet formation by stripping away mass from young protoplanetary disks and by inhibiting grain growth to large sizes.  Significant evidence of this reduction, however, has been elusive.

In this thesis talk, I present interferometric millimeter- and radio-wave continuum studies of the impact of stellar companions on young protoplanetary disks. In the first half of my talk, I present a large Submillimeter Array survey of multiples in the nearby Taurus-Auriga star forming region.  I demonstrate with this survey that companions have dramatic effects on protoplanetary disk masses and lifetimes, but that theoretical models of disk truncation fail to match observations of disk radii.  During the second part of my talk, I focus on the grain growth properties of disks in three multiple systems.  I present high-resolution, multi-band interferometric studies of the disks in the UZ Tau quadruple system, the AS 205 triple system, and the UX Tau quadruple system.  Using these observations, I find evidence for radial variations in dust properties in protoplanetary disks that are consistent with theoretical models.  I find no evidence that companions have significant impact on grain growth to large sizes.