Polarization of radiation of electrons in highly turbulent magnetic fields

TL;DR

This paper investigates the polarization characteristics of jitter and synchrotron radiation emitted by electrons in highly turbulent, anisotropic magnetic fields, revealing how polarization relates to magnetic field geometry and turbulence spectrum.

Contribution

It provides new insights into how polarization of radiation reflects magnetic field geometry and turbulence spectrum in highly turbulent environments.

Findings

Polarization degree of synchrotron radiation exceeds that of jitter radiation for monoenergetic electrons.

The polarization relation depends on the electron energy distribution and spectral index.

Polarization measurements can reveal magnetic field geometry and turbulence properties.

Abstract

We study the polarization properties of the jitter and synchrotron radiation produced by electrons in highly turbulent anisotropic magnetic fields. The net polarization is provided by the geometry of the magnetic field the directions of which are parallel to a certain plane. Such conditions may appear in the relativistic shocks during the amplification of the magnetic field through the so-called Weibel instability. While the polarization properties of the jitter radiation allows extraction of direct information on the turbulence spectrum as well as the geometry of magnetic field, the polarization of the synchrotron radiation reflects the distribution of the magnetic field over its strength. For the isotropic distribution of monoenergetic electrons, we found that the degree of polarization of the synchrotron radiation is larger than the polarization of the jitter radiation. For the power-law energy distribution of electrons the relation between the degree of polarization of synchrotron and jitter radiation depends on the spectral index of the distribution.