Type I planet migration in nearly laminar disks - long term behavior

TL;DR

This study uses high-resolution 2-D simulations to explore how disk viscosity influences type I planet migration, revealing different damping mechanisms, long-term behaviors, and effects of vortex instabilities in nearly laminar disks.

Contribution

It provides new insights into the dependence of planet migration on disk viscosity and discusses the roles of density wave damping and vortex instabilities.

Findings

Migration depends strongly on disk viscosity.

Two damping mechanisms identified: viscosity dominated and shock dominated.

Vortex instability influences long-term migration behavior.

Abstract

We carry out 2-D high resolution numerical simulations of type I planet migration with different disk viscosities. We find that the planet migration is strongly dependent on disk viscosities. Two kinds of density wave damping mechanisms are discussed. Accordingly, the angular momentum transport can be either viscosity dominated or shock dominated, depending on the disk viscosities. The long term migration behavior is different as well. Influences of the Rossby vortex instability on planet migration are also discussed. In addition, we investigate very weak shock generation in inviscid disks by small mass planets and compare the results with prior analytic results.