2024/05/10 by Jiasheng Li, Li, Jia-Sheng, Mi-Xiang Lan +3
Physics and Astronomy · #FOS: Physical sciences #Gamma-ray bursts and supernovae #High Energy Astrophysical Phenomena (astro-ph.HE)
paper · pdf · doi:10.48550/arxiv.2405.06182
openalex publication_date 2024/05/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The time-integrated polarization degree (PD) at prompt optical band of gamma-ray burst (GRB) was predicted to be less than 20%, while the time-resolved one can reach as high as 75% in photosphere model. Polarizations in optical band during GRB prompt phase had not been studied under framework of the magnetic reconnection model. Here, a three-segment power laws of the energy spectrum is used to reconstruct the Stokes parameters of the magnetic reconnection model. The multi-wavelength light curves and polarization curves from the optical band to MeV gamma-rays in GRB prompt phase are studied. We found depending mainly on the jet dynamics there is a long lasting high PD phase at all calculated energy bands for the typical parameter sets. The time-resolved PD could be as high as 50%, while the time-integrated one is roughly 17%) in optical band. It can reach 60% for the time-resolved PD in X-rays and the time-integrated one is around (30-40)%. The polarization angle (PA) evolution is random in both optical and gamma-ray bands for the photosphere model, while it is roughly a constant in the synchrotron models. Therefore, future time-resolved PA observations in the prompt optical or gamma-ray band could distinguish between the photosphere and the synchrotron models.