Research Highlights

On the Orbital Evolution of a Jovian Planet Embedded in a Self-Gravitating Disk

Zhang, Yuan, Lin, & Yen, 2008, ApJ, 676, 639

We performed a series of hydrodynamic simulations to investigate the orbital evolution of a Jovian planet embedded in a proto-stellar disk. In order to take into account of the effect of the disk's self-gravity, we developed and adopted an \textbf{Antares} code which is based on a 2-D Godunov scheme to obtain the exact Reimann solution for isothermal or polytropic gas, with non- reflecting boundary conditions. Our simulations indicate that in the study of the runaway (type III) migration, it is important to carry out a fully self consistent treatment of the gravitational interaction between the disk and the embedded planet. Through a series of convergence tests, we show that adequate numerical resolution, especially within the planet's Roche lobe, critically determines the outcome of the simulations. We consider a variety of initial conditions and show that isolated, non eccentric protoplanets do not undergo type III migration. We attribute the difference between our and previous simulations to the contribution of a self-consistent representation of the disk's self-gravity. Nevertheless, type III migration cannot be completely suppressed and its onset requires finite amplitude perturbations such as that induced by planet-planet interaction. We determine the radial extent of type III migration as a function of the disk's self-gravity.