High-growth-rate magnetohydrodynamic instability in differentially rotating compressible flow

TL;DR

This paper investigates a high-growth-rate magnetohydrodynamic instability in differentially rotating compressible flows, which could explain turbulence and angular momentum transport in accretion disks, especially where magnetic energy dominates rotational energy.

Contribution

It identifies a new high-growth-rate instability in magnetized, differentially rotating compressible flows, expanding understanding of turbulence sources in accretion disks.

Findings

Instability occurs when magnetic energy exceeds rotational energy.

High growth rate of the instability identified.

Potential role in angular momentum transport in accretion disks.

Abstract

The transport of angular momentum in the outward direction is the fundamental requirement for accretion to proceed in an accretion disc. This objective can be achieved if the accretion flow is turbulent. Instabilities are one of the sources for the turbulence. We study a differentially rotating compressive flow in the presence of non vanishing radial and azimuthal magnetic field and demonstrate the occurrence of a high growth rate instability. This instability operates in a region where magnetic energy density exceeds the rotational energy density.