Origin of intense electron heating in relativistic blast waves

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.

9 pages, 8 figures; to be published in Astrophysical Journal Letters

References in corpus (7)

• Multi-messenger Observations of a Binary Neutron Star Merger
• The Physics of Gamma-Ray Bursts and Relativistic Jets
• On the structure of relativistic collisionless shocks in electron-ion plasmas
• Teraelectronvolt emission from the $\gamma$-ray burst GRB 190114C
• A very-high-energy component deep in the Gamma-ray Burst afterglow
• Exact relativistic kinetic theory of an electron beam-plasma system: hierarchy of the competing modes in the system parameter space
• Efficient electron heating in relativistic shocks and gamma ray burst afterglow

Cited by in corpus (4)

• Magnetic Field Amplification and Particle Acceleration in Weakly Magnetized Trans-relativistic Electron-ion Shocks
• Energy Dissipation in Strong Collisionless Shocks: The Crucial Role of Ion-to-Electron Scale Separation in Particle-in-Cell Simulations
• Ion-electron instabilities in the precursor of weakly magnetized, transrelativistic shocks
• Energy partition in collisionless counterstreaming plasmas