Long-time evolution of magnetic fields in relativistic GRB shocks
Astrophysics
2009-11-10 v1
Abstract
We investigate the long-time evolution of magnetic fields generated by the two-stream instability at ultra- and sub-relativistic astrophysical collisionless shocks. Based on 3D PIC simulation results, we introduce a 2D toy model of interacting current filaments. Within the framework of this model, we demonstrate that the field correlation scale in the region far downstream the shock grows nearly as the light crossing time, lambda(t) ~ ct, thus making the diffusive field dissipation inefficient. The obtained theoretical scaling is tested using numerical PIC simulations. This result extends our understanding of the structure of collisionless shocks in gamma-ray bursts and other astrophysical objects.
Keywords
Cite
@article{arxiv.astro-ph/0409382,
title = {Long-time evolution of magnetic fields in relativistic GRB shocks},
author = {Mikhail V. Medvedev and Massimiliano Fiore and Ricardo A. Fonseca and Luis O. Silva and Warren B. Mori},
journal= {arXiv preprint arXiv:astro-ph/0409382},
year = {2009}
}
Comments
5 pages. 2 figures. Submitted to ApJL