Vortices in self-gravitating disks

TL;DR

This study investigates how self-gravity influences vortex behavior in disks, revealing that vortices are transient and may be less effective in trapping dust, impacting planet formation theories.

Contribution

The paper provides the first detailed numerical analysis of vortex dynamics in self-gravitating disks, highlighting their transient nature and coupling with density waves.

Findings

Vortices are transient, recurring structures in self-gravitating disks.

Vortices grow to sizes comparable to the local Jeans scale before shearing apart.

Coupling between vortices and density waves influences disk dynamics.

Abstract

Vortices are believed to greatly help the formation of km sized planetesimals by collecting dust particles in their centers. However, vortex dynamics is commonly studied in non-self-gravitating disks. The main goal here is to examine the effects of disk self-gravity on the vortex dynamics via numerical simulations. In the self-gravitating case, when quasi-steady gravitoturbulent state is reached, vortices appear as transient structures undergoing recurring phases of formation, growth to sizes comparable to a local Jeans scale, and eventual shearing and destruction due to gravitational instability. Each phase lasts over 2-3 orbital periods. Vortices and density waves appear to be coupled implying that, in general, one should consider both vortex and density wave modes for a proper understanding of self-gravitating disk dynamics. Our results imply that given such an irregular and rapidly changing, transient character of vortex evolution in self-gravitating disks it may be difficult for such vortices to effectively trap dust particles in their centers that is a necessary process towards planet formation.