Compton scattering of polarized light in two-phase accretion discs
Abstract
The differences between the exact matrix of the Compton scattering and the Rayleigh matrix of Thomson scattering have been investigated. We present the Compton scattering formalism and, to illustrate this, compute the polarization of radiation from a two-phase accretion disc as a function of frequency and emission angle. The disc was assumed to be plane parallel and consisting of two parts: 1. optically thick and cool inner disc emitting black body radiation and 2. hot optically thin accretion disc corona (ADC). The central object was assumed not to contribute to the X-ray luminosity and we neglected the radiation of the corona. The radiative transfer equation of polarized light was solved in the approximation of single scattering taking into account the exact Compton matrix. It is shown that for high electron temperatures or for large differences between the disc and coronal temperatures the Rayleigh matrix predicts much larger polarization values than the Compton matrix.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- August 1993
- Bibcode:
- 1993A&A...275..337P
- Keywords:
-
- accretion discs;
- X-rays: general;
- polarization;
- scattering;
- X-rays: galaxies