Relativistic magnetohydrodynamical simulations of the resonant corrugation of a fast shock front

TL;DR

This study uses relativistic magnetohydrodynamic simulations to explore how fast shock fronts interact with upstream perturbations, revealing a resonant response in shock corrugation and examining both linear and non-linear regimes.

Contribution

It demonstrates the existence of a resonance in shock corrugation amplitude when downstream wave group velocity matches shock speed, advancing understanding of shock-turbulence interactions.

Findings

Resonant response of shock corrugation at specific wave conditions

Transmission of upstream perturbations into downstream turbulence

Non-linear effects observed with large amplitude waves

Abstract

The generation of turbulence at magnetized shocks and its subsequent interaction with the latter is a key question of plasma- and high-energy astrophysics. This paper presents two-dimensional magnetohydrodynamic simulations of a fast shock front interacting with incoming upstream perturbations, described as harmonic entropy or fast magnetosonic waves, both in the relativistic and the sub-relativistic regimes. We discuss how the disturbances are transmitted into downstream turbulence and we compare the observed response for small amplitude waves to a recent linear calculation. In particular, we demonstrate the existence of a resonant response of the corrugation amplitude when the group velocity of the outgoing downstream fast mode matches the velocity of the shock front. We also present simulations of large amplitude waves to probe the non-linear regime.