Investigating polarization signatures from GRB models

Abstract

There is still much debate around the inner workings of the GRB prompt emission phase with many questions still left unanswered. Polarization signatures offer a promising new avenue to discriminate between the various GRB prompt emission models. The aim of this study is to estimate energy and time resolved polarization signatures resulting from Inverse Compton (IC) scattering for two specific GRB prompt emission models, namely the backscatter-dominated cork model by \citet{Vyas2} and a Compton drag model by \citet{Lazzati2}. In order to achieve this we apply an IC polarization Monte Carlo (MC) algorithm to those two GRB models in order to estimate the expected polarization signatures. For the backscatter-dominated cork model we find polarization signatures below $\sim 10$~\%, likely below the detection limits of current or near-future X-ray and $\gamma$-ray polarimeters. Our results for the Compton drag model indicates polarization results consistent with that found by \citet{Lazzati3}. Furthermore, we find some energy and time dependence of the estimated polarization, particularly for the polarization angle.