# Linear Polarization, Circular Polarization, and Depolarization of Gamma-ray Bursts: A Simple Case of Jitter Radiation

## TL;DR

This paper presents a simplified model of gamma-ray burst polarization using jitter radiation in a turbulent magnetic slab, explaining observed polarization features and depolarization effects across wavelengths.

## Contribution

It introduces a novel model combining jitter radiation and turbulent Faraday effects to explain GRB polarization and depolarization phenomena.

## Key findings

- Jitter radiation can produce linear polarization in GRBs.
- Turbulent Faraday rotation causes wavelength-dependent depolarization.
- Polarized jitter radiation transfer explains optical and radio polarization observations.

## Abstract

Linear and circular polarizations of gamma-ray bursts (GRBs) have been detected during recent years. We adopt a simplified model to investigate GRB polarization characteristics in this paper. A compressed two-dimensional turbulent slab containing stochastic magnetic fields is considered, and jitter radiation can produce the linear polarization under this special magnetic field topology. Turbulent Faraday rotation measure (RM) of this slab makes strong wavelength-dependent depolarization. The jitter photons can also scatter with those magnetic clumps inside the turbulent slab, and a nonzero variance of the Stokes parameter $V$ can be generated. Furthermore, the linearly and circularly polarized photons in the optical and radio bands may suffer heavy absorptions from the slab. Thus we consider the polarized jitter radiation transfer processes. Finally, we compare our model results with the optical detections of GRB 091018, GRB 121024A, and GRB 131030A. We suggest simultaneous observations of GRB multi-wavelength polarization in the future.