Title: Signposts of Planet Formation in Protoplanetary Disks
Spekaer: Dr. Ruobing Dong (UC Berkeley, Hubble Fellow)
Time: Dec. 2nd, 10:00pm, 3rd floor, middle conference room
Abstract: Planets form in protoplanetary disks, which are gaseous disks surrounding newly born stars. Theoretically, we think planets can excite asymmetric structures such as spiral density waves or clumps, and may clear material around their orbits to form gaps, through gravitational disk-planet interactions. It has been suggested that the gaps and cavities recently discovered in resolved observations of some protoplanetary disks (in particular the so called "transitional disks") are created by planets. To explore this scenario, we combine two-dimensional two fluid (gas + particle) hydrodynamical calculations with fully three-dimensional Monte Carlo Radiative Transfer simulations, to study the observational signatures of gaps opened by one or several planets, making qualitative comparisons with observations. Overall, our results suggest that the planet-opening-gap scenario is a promising way to explain the origin of the gaps and cavities found in protoplanetary disks. Specifically, inspired by the recent ALMA release of the image of the HL Tau disk, we show that multiple narrow gaps, well separated by bright rings, can be opened by 0.2MJ planets soon after their formation in a relatively massive disk.
