Early-Time Stability of Decelerating Shocks

TL;DR

This paper analyzes the stability of decelerating shocks with finite thickness, clarifying the role of compressibility and providing insights relevant for astrophysical shock experiments.

Contribution

It extends the understanding of Vishniac instability by including finite layer effects and clarifies the dependence on compressible dynamics.

Findings

Finite layer thickness influences shock stability.

Compressibility effects are crucial away from the shock front.

Results inform experimental design for astrophysical shock replication.

Abstract

We consider the decelerating shock instability of Vishniac for a finite layer of constant density. This serves both to clarify which aspects of the Vishniac instability mechanism depend on compressible effects away from the shock front and also to incorporate additional effects of finite layer thickness. This work has implications for experiments attempting to reproduce the essential physics of astrophysical shocks, in particular their minimum necessary lateral dimensions to contain all the relevant dynamics.