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arXiv · 1311.4313

Gamma-ray burst polarization via Compton scattering process

Zhe Chang·Hai-Nan Lin·Yunguo Jiang
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Abstract

Synchrotron radiation and Compton scattering are widely accepted as the most likely emission mechanisms of some astrophysical phenomena, such as gamma-ray bursts (GRBs) and active galactic nuclei (AGNs). The measurement on polarization of photons provides a useful tool to distinguish different emission mechanisms and structures of the emission region. Based on the differential cross section of a polarized photon scattered by an unpolarized electron of any initial momentum, we derive analytical formula of polarization for beamed photons scattered by isotropic electrons with a power law distribution. Numerical calculations are carried out in four special cases: electrons at rest, Thomson limit, head-on collision and monochromatic electrons. It is found that the maximum polarization can be as high as $100\%$ for low energy photons, if the electrons are at rest. Although polarization is highly suppressed due to the isotropic electrons, a maximum value of $\sim 10\% \-- 20\%$ can still be achieved. Compton scattering process can be used to explain the polarization of GRB 041219A and GRB 100826A.

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Zhe Chang, Hai-Nan Lin, Yunguo Jiang. 2014-02-16. Gamma-ray burst polarization via Compton scattering process. https://doi.org/10.1088/0004-637x%2F783%2F1%2F30

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