High Energy Polarimetry of Prompt GRB Emission

Understand

Evidence of polarized $\gamma$-ray emission ($>$ 50 keV) from Gamma-Ray Bursts (GRBs) has been accumulated in recent years.

• Measurements have been reported with levels in the range of 30-80\%, typically with limited statistical significance.
• No clear picture has yet emerged with regards to the polarization properties of GRBs.
• Taken at face value, the data suggest that most GRBs have a relatively large level of polarization (typically, $> 50\%$), which may suggest synchrotron emission associated with an ordered magnetic field structure within the GRB jet.