The Burst Mode of Accretion in Primordial Star Formation

TL;DR

This paper uses 2+1D simulations to study how primordial protostellar disks form, fragment, and cause burst accretion events, impacting early star growth.

Contribution

It introduces a detailed simulation of primordial star formation showing burst accretion driven by disk fragmentation and inward migration of gaseous clumps.

Findings

Disk fragmentation leads to gaseous clumps.

Clumps are accreted onto the protostar, causing bursts.

Burst events influence protostar growth.

Abstract

We present simulation results for the formation and long-term evolution of a primordial protostellar disk harbored by a first star. Using a 2+1D nonaxisymmetric thin disk numerical simulation, together with a barotropic relation for the gas, we are able to probe ~20 kyr of the disk's evolution. During this time period we observe fragmentation leading to loosely bound gaseous clumps within the disk. These are then torqued inward and accreted onto the growing protostar, giving rise to a burst phenomenon. The luminous feedback produced by this mechanism may have important consequences for the subsequent growth of the protostar.