Towards Understanding Jovian Planet Migration

We present 2D hydrodynamic simulations of circumstellar disks around protostars using a `Piecewise Parabolic Method' (PPM) code. We include a point mass embedded within the disk and follow the migration of that point mass through the disk. Companions with masses $M_c\ga 0.5M_J$ can open a gap in the disk sufficient to halt rapid migration through the disk. Lower mass companions open gaps, but migration continues because sufficient disk mass remains close to the disk to exert large tidal torques. We find that the torques which dominate the migration of low mass planets originate within a radial region within 1-2 Hill radii of the planet's orbit radius, a distance smaller than the thickness of the disk. We conclude that a very high resolution 3D treatment will be required to adequately describe the planet's migration.