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arXiv · 2204.00546

Origin of intense electron heating in relativistic blast waves

Arno Vanthieghem·Martin Lemoine·Laurent Gremillet
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Abstract

The modeling of gamma-ray burst afterglow emission bears witness to strong electron heating in the precursor of Weibel-mediated, relativistic collisionless shock waves propagating in unmagnetized electron-ion plasmas. In this Letter, we propose a theoretical model, which describes electron heating via a Joule-like process caused by pitch-angle scattering in the decelerating, self-induced microturbulence and the coherent charge-separation field induced by the difference in inertia between electrons and ions. The emergence of this electric field across the precursor of electron-ion shocks is confirmed by large-scale particle-in-cell (PIC) simulations. Integrating the model using a Monte Carlo-Poisson method, we compare the main observables to the PIC simulations to conclude that the above mechanism can indeed account for the bulk of electron heating.

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Arno Vanthieghem, Martin Lemoine, Laurent Gremillet. 2022-04-01. Origin of intense electron heating in relativistic blast waves. https://doi.org/10.3847/2041-8213%2Fac634f

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