Self-Sustaining Vortices in Protoplanetary Disks: Setting the Stage for Planetary System Formation

TL;DR

This paper investigates how self-sustaining vortices in protoplanetary disks, driven by dust-gas interactions and instabilities, create stable structures that facilitate planetesimal formation, advancing understanding of planetary system origins.

Contribution

It introduces GPU-based simulations of dust-gas dynamics showing vortex formation and stability, linking viscous ring-instability to planetesimal formation processes.

Findings

Dust rings become Rossby unstable and break into vortices

Vortices form stable structures conducive to planetesimal formation

Self-sustaining vortices align with observed exoplanet environments

Abstract

The core accretion scenario of planet formation assumes that planetesimals and planetary embryos are formed during the primordial, gaseous phases of the protoplanetary disk. However, how the dust particles overcome the traditional growth barriers is not well understood. The recently proposed viscous ring-instability may explain the concentric rings observed in protoplanetary disks by assuming that the dust grains can reduce the gas conductivity, which can weaken the magneto-rotational instability. We present an analysis of this model with the help of GPU-based numerical hydrodynamic simulations of coupled gas and dust in the thin-disk limit. During the evolution of the disk the dusty rings become Rossby unstable and break up into a cascade of small-scale vortices. The vortices form secularly stable dusty structures, which could be sites of planetesimal formation by the streaming instability as well as direct gravitational collapse. The phenomenon of self-sustaining vortices is consistent with observational constraints of exoplanets and sets a favorable environment for planetary system formation.