Mildly relativistic magnetized shocks in electron–ion plasmas – II. Particle acceleration and heating

Abstract

ABSTRACT Particle acceleration and heating at mildly relativistic magnetized shocks in electron–ion plasma are investigated with unprecedentedly high-resolution 2D particle-in-cell simulations that include ion-scale shock rippling. Electrons are super-adiabatically heated at the shock, and most of the energy transfer from protons to electrons takes place at or downstream of the shock. We are the first to demonstrate that shock rippling is crucial for the energization of electrons at the shock. They remain well below equipartition with the protons. The downstream electron spectra are approximately thermal with a limited supra-thermal power-law component. Our results are discussed in the context of wakefield acceleration and the modelling of electromagnetic radiation from blazar cores.