Corrugation of relativistic magnetized shock waves

TL;DR

This paper analyzes how relativistic magnetized shock waves develop corrugation when interacting with turbulence, revealing resonance phenomena that could significantly impact astrophysical shock wave behavior.

Contribution

It provides a linear perturbation analysis of relativistic MHD shock corrugation, including transfer functions and resonance conditions, advancing understanding of shock-turbulence interactions.

Findings

Resonance causes large or divergent shock responses.

Transfer functions depend on upstream magnetization and incoming wave type.

Corrugation influences astrophysical shock wave phenomenology.

Abstract

As a shock front interacts with turbulence, it develops corrugation which induces outgoing wave modes in the downstream plasma. For a fast shock wave, the incoming wave modes can either be fast magnetosonic waves originating from downstream, outrunning the shock, or eigenmodes of the upstream plasma drifting through the shock. Using linear perturbation theory in relativistic MHD, this paper provides a general analysis of the corrugation of relativistic magnetized fast shock waves resulting from their interaction with small amplitude disturbances. Transfer functions characterizing the linear response for each of the outgoing modes are calculated as a function of the magnetization of the upstream medium and as a function of the nature of the incoming wave. Interestingly, if the latter is an eigenmode of the upstream plasma, we find that there exists a resonance at which the (linear) response of the shock becomes large or even diverges. This result may have profound consequences on the phenomenology of astrophysical relativistic magnetized shock waves.