Polarized Images of Synchrotron Radiations in Curved Spacetime

TL;DR

This paper derives formulas for the polarization and luminosity of synchrotron radiation in curved spacetime and applies them to visualize polarized images near a Schwarzschild black hole, revealing how polarization varies with observation angle.

Contribution

It introduces new formulas for polarization and luminosity of synchrotron radiation in curved spacetime and applies them to black hole environments, providing visualizations of polarized images.

Findings

Polarization directions vary with observational angles.

Polarized images depend on electron orbit positions.

Formulas are applicable to curved spacetime scenarios.

Abstract

In this work, we derive two formulas encoding the polarization direction and luminosity of synchrotron radiations from the moving electrons in curved spacetime under the geometric optics approximation. As an application, we further study the polarized images of synchrotron radiations from electron sources in Schwarzschild black hole spacetime with a vertical and uniform magnetic field. In particular, by focusing on the circular orbits of electrons on the equatorial plane, we show the polarized images of the synchrotron radiations from these orbits for different observational angles and discuss the variations of the polarization directions concerning the angles.