Field amplification, vortex formation, and electron acceleration in a plasma protoshock: effect of asymmetric density profile

TL;DR

This study models asymmetric plasma collisions in relativistic jets, revealing electron acceleration to high energies and vortex formation, which are key to understanding magnetic field amplification in gamma-ray burst shocks.

Contribution

It introduces a model of asymmetric density effects in plasma collisions, showing how electron acceleration and vortex dynamics occur in relativistic jet shocks.

Findings

Electrons are accelerated to Lorentz factors of ~300.

Filaments are deflected and form vortices that merge into larger structures.

Magnetic field amplification occurs through vortex dynamics.

Abstract

Gamma ray bursts (GRBs) are thought to originate from highly relativistic jets. The fireball model predicts internal shocks in the jets, causing magnetic field to be amplified and particles to be accelerated. We model the effects of an asymmetric density configuration for an internal plasma collision in a quasi-parallel magnetic field. We measured electron acceleration and found that a tenuous population of electrons is accelerated to Lorentz factors of \sim 300 - close to energy equipartition with ions. We found that the filaments did not remain static, but were deflected by the Lorentz force and rolled up into small vortices, which themselves merge to form a larger current vortex.