Relativistic Photon Mediated Shocks

TL;DR

This paper derives and solves equations describing the structure of relativistic, photon-mediated shocks, revealing how photon anisotropy increases with shock velocity and demonstrating solution convergence with higher truncation orders.

Contribution

It introduces a new set of equations for relativistic radiation shocks and analyzes photon anisotropy and solution convergence.

Findings

Photon anisotropy approaches perfect beaming at high Lorentz factors

Solutions converge as the truncation order increases

Provides a framework for steady relativistic radiation shock analysis

Abstract

A system of equations governing the structure of a steady, relativistic radiation dominated shock is derived, starting from the general form of the transfer equation obeyed by the photon distribution function. Closure is obtained by truncating the system of moment equations at some order. The anisotropy of the photon distribution function inside the shock is shown to increase with increasing shock velocity, approaching nearly perfect beaming at upstream Lorentz factors $\Gamma_{-}>>1$. Solutions of the shock equations are presented for some range of upstream conditions. These solutions are shown to converge as the truncation order is increased.