Radiative transfer in ultra-relativistic outflows
Abstract
Analytical and numerical solutions are obtained for the equation of radiative transfer in ultra-relativistic opaque jets. The solution describes the initial trapping of radiation, its adiabatic cooling, and the transition to transparency. Two opposite regimes are examined: (1) Matter-dominated outflow. Surprisingly, radiation develops enormous anisotropy in the fluid frame before decoupling from the fluid. The radiation is strongly polarized. (2) Radiation-dominated outflow. The transfer occurs as if radiation propagated in vacuum, preserving the angular distribution and the blackbody shape of the spectrum. The escaping radiation has a blackbody spectrum if (and only if) the outflow energy is dominated by radiation up to the photospheric radius.
Cite
@article{arxiv.1011.6005,
title = {Radiative transfer in ultra-relativistic outflows},
author = {Andrei M. Beloborodov},
journal= {arXiv preprint arXiv:1011.6005},
year = {2015}
}
Comments
12 pages, 8 figures, accepted to ApJ