Faraday Conversion and Rotation In Uniformly Magnetized Relativistic Plasmas

TL;DR

This paper offers precise formulas for Faraday conversion and rotation in relativistic plasmas, aiding interpretation of polarization in astrophysical jets and accretion flows, especially for Sgr A*.

Contribution

It provides new fitting formulas for Faraday coefficients applicable to various particle distributions, improving accuracy in polarization studies of relativistic plasmas.

Findings

Faraday conversion coefficient approaches zero at high particle energies.

Non-linear corrections are crucial for accurate CP interpretation of Sgr A*.

Formulas are applicable to thermal and power-law particle distributions.

Abstract

We provide precise fitting formulae for Faraday conversion and rotation coefficients in uniformly magnetized relativistic plasma. The formulae are immediately applicable to Rotation Measure and Circular Polarization (CP) production in jets and hot accretion flows. We show the recipe and results for arbitrary isotropic particle distributions, in particular thermal and power-law. The exact Faraday conversion coefficient is found to approach zero with the increasing particle energy. The non-linear corrections of Faraday conversion and rotation coefficients are found essential for reliable CP inter- pretation of Sgr A*.