A fast current-driven instability in relativistic collisionless shocks

TL;DR

This paper identifies a rapid current-driven instability in relativistic collisionless shocks, which likely influences shock physics and particle acceleration, surpassing previously known instabilities in growth rate.

Contribution

It introduces a new, faster-growing current-driven instability in relativistic shocks, highlighting its potential impact on shock dynamics and particle acceleration processes.

Findings

The instability grows faster than other known instabilities.

It is triggered by the perpendicular current of supra-thermal particles.

It likely influences shock structure and particle acceleration.

Abstract

We report here on a fast current-driven instability at relativistic collisionless shocks, triggered by the perpendicular current carried by the supra-thermal particles as they gyrate around the background magnetic field in the shock precursor. We show that this instability grows faster than any other instability studied so far in this context, and we argue that it is likely to shape the physics of the shock and of particle acceleration in a broad parameter range.