Toroidal vortices as a solution to the dust migration problem

TL;DR

This paper demonstrates that toroidal vortices in protoplanetary discs, caused by dust-gas interactions, can halt the radial migration of large dust grains, offering a natural solution to the dust migration problem.

Contribution

It introduces the role of toroidal vortices in stopping dust migration in protoplanetary discs, based on simulations with two dust grain sizes.

Findings

Toroidal vortices are triggered by mm grains interacting with gas.

Vortices prevent radial migration of metre-sized dust.

Potential solution to the dust migration problem in planet formation.

Abstract

In an earlier letter, we reported that dust settling in protoplanetary discs may lead to a dynamical dust-gas instability that produces global toroidal vortices. In this letter, we investigate the evolution of a dusty protoplanetary disc with two different dust species (1 mm and 50 cm dust grains), under the presence of the instability. We show how toroidal vortices, triggered by the interaction of mm grains with the gas, stop the radial migration of metre-sized dust, potentially offering a natural and efficient solution to the dust migration problem.