2023/06/29 by Li, Jia-Sheng, Hao-Bing Wang, Wang, Hao-Bing +2 · 1 citation
Physics and Astronomy · #FOS: Physical sciences #Gamma-ray bursts and supernovae #High Energy Astrophysical Phenomena (astro-ph.HE) #Solar and Space Plasma Dynamics #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2306.16618
openalex publication_date 2023/06/29 · openalex created_date 2023/07/01 · openalex updated_date 2026/07/28
In addition to the light curve and energy spectrum, polarization is also important for inferring the physical properties of the Gamma-ray burst (GRB). Rotation of the polarization angle (PA) with time will cause depolarization of the time-integrated polarization degree. However, it is rarely studied before. Here, we use a magnetic reconnection model with a large-scale ordered aligned magnetic field in the emitting region to study the influence of the parameters on the PA rotations in GRB prompt phase. We find that half-opening angle of the jet θj, the observational angle θV, and the bulk Lorentz factor Γ all have significant impacts on the PA rotations. The PA rotations are affected by the product value of θjΓ0 (Γ0 is the normalization factor of Γ with Γ(r)=Γ0(r/r0)s), but are roughly independent of the concrete values of both θj and Γ0. For the typical parameters, the changes of the PA within T90 (\trianglePA) would be within (12^∘, 66^∘) for slight off-axis observations, where T90 is the duration of the burst with the accumulated flux density ranging from 5% to 95%. The q range for \trianglePA>10∘ becomes smaller with the increase of the product value of θjΓ0. The most significant PA rotation with \trianglePA∼90∘ will happen when θjΓ0>50 and 1.0