Clumpy accretion in pre-main-sequence stars as a source of perturbations in circumstellar disks

TL;DR

This study uses 3D hydrodynamical simulations and radiative transfer calculations to show that clumpy accretion events can generate observable spiral and ring structures in circumstellar disks, similar to ALMA observations.

Contribution

It demonstrates that clumpy accretion can produce observable disk perturbations, providing a potential explanation for observed structures in protoplanetary disks.

Findings

Density waves form at clump fall and evolve into spirals and rings.

Simulated disk images match ALMA observations.

Clumpy accretion may explain observed disk structures.

Abstract

The development of perturbations in the circumstellar disks of pre-main-sequence stars caused by clumpy accretion was investigated. Here we perform 3D hydrodynamical smoothed particle hydrodynamics simulations of disks perturbed by a recent clump accretion event. These simulations are further explored by radiative transfer calculations to quantify the observational appearance of such disks. It was shown that the density waves in the disks were formed at the fall of the clump. After several revolutions they can transform into spirals and ring structures. Their images in millimeter wavelengths are very similar to those observed with Atacama Large Millimeter/submillimeter Array in some protoplanetary disks. We assume that clumpy accretion may be the source of such structures.