date: 2009 Feb 23(Mon) 12:00 - 13:00
room: Hokkaido University, Science Bldg. #8, Prof. Kuramoto's office,
Hokkaido University, ILTS Exp. Bldg. 2F seminar room,
Kobe University, Shizen Bldg. #3, room 508,
(This seminar is a teleconference by the use of video-conferencing system.)
speaker: Dr. Kou Yamada (Waseda University)
title: Type-I Planetary Migration in an Accretion Disk
abstract: A planet embedded in a protoplanetary gaseous disk experiences a torque from the disk which generally leads to its orbital decay toward the central object. We investigate planet-accretion disk interactions in the case of an adiabatic disk and a disk with a locally isothermal equation of state by means of two-dimensional hydrodynamic simulations with exact Riemann solver. From the comparison with both numerical results, entropy perturbations, that are advected in the planet's coorbital region, yield an excess of corotation torque which may be large enough to slow down the migration process.