Effects of Stress Evolution Process on the Thermal Stability of Thin Accretion Discs

TL;DR

This paper investigates how incorporating stress evolution into the stability analysis of thin accretion discs affects their thermal stability, potentially explaining observed variability in certain astrophysical systems.

Contribution

It introduces the stress evolution process into the linear stability analysis of thin accretion discs, revealing its impact on thermal instability growth rates.

Findings

Stress delay reduces growth rate of unstable modes

Potential explanation for GRS 1915+105 variability

Application to Shapiro-Lightman-Eardley disc stability

Abstract

The stress evolution process is taken into account in the linear stability analysis of standard thin accretion discs. We find that the growth rate of thermally unstable modes can decrease significantly owing to the stress delay, which may help to understand the quasi-periodic variability of GRS 1915+105. We also discuss possible application of stress evolution to the stability of Shapiro-Lightman-Eardley disc.