Evolution of the Solar Nebula. VII. Formation and Survival of Protoplanets Formed by Disk Instability

Abstract

A major concern for the disk instability mechanism for giant planet formation is survival of the self-gravitating clumps that form in a marginally gravitationally unstable disk. Previous grid-based calculations have found that these clumps may only survive for an orbital period or two, an outcome that has been attributed to insufficient spatial resolution of the clumps. Here we use the highest spatial resolution grid-based models to date (effectively over 8 × 106 grid points, with a locally refined radial grid and 1024 azimuthal grid points) to demonstrate that clump formation and survival are enhanced as the numerical resolution is increased, even with a full treatment of disk thermodynamics and radiative transfer. The overall disk evolution appears to be converging toward a solution with robust spiral arms and self-gravitating protoplanets. The survival of these protoplanets is then further explored by introducing