Vortex migration in protoplanetary discs

Sijme-Jan Paardekooper,John C B Papaloizou,Geoffroy Lesur,P Barge,L Jorda

doi:10.1051/epjconf/20134605001

Abstract

Vortices embedded in protoplanetary discs can act as obstacles to the unper- turbed disc flow. The resulting velocity perturbations propagate away from the vortex in the form of density waves that transport angular momentum. Any asymmetry between the inner and the outer density wave means that the region around the vortex has to change its angular momentum. We find that this leads to orbital migration of the vortex. Asymmet- ric waves always arise except in the case of a disc with constant pressure, for isothermal as well as non-isothermal discs. Depending on the size and strength of the vortex, the resulting migration time scales can be as short as a few thousand orbits.

Highlights

Vortices are capable of playing a key role in concentrating solid particles, an essential stage in the formation process of planets [1]
Could the enhanced solid concentration inside vortices considerably speed up the formation of planets [2], inside a vortex solids would be safe from radial drift due to a mismatch in gas and solid angular velocity caused by a pressure gradient in the gas disc [3]
We show that vortices themselves are subject to radial migration, driven by the same pressure gradient that causes solid particles to drift inward at alarmingly short time scales

Summary

Introduction

Vortices are capable of playing a key role in concentrating solid particles, an essential stage in the formation process of planets [1]. Could the enhanced solid concentration inside vortices considerably speed up the formation of planets [2], inside a vortex solids would be safe from radial drift due to a mismatch in gas and solid angular velocity caused by a pressure gradient in the gas disc [3]. In this contribution, we show that vortices themselves are subject to radial migration, driven by the same pressure gradient that causes solid particles to drift inward at alarmingly short time scales. For a more detailed description we refer to [4]

Density wave emission

Wave asymmetries

Results

Consequences

Conclusions