论文标题
解释伽马射线爆发及时发射的时间集成极化数据
Interpreting time-integrated polarization data of gamma-ray burst prompt emission
论文作者
论文摘要
目标。随着伽马射线爆发（GRB）及时阶段的极化数据的积累，可以测试极化模型。方法。我们预测了具有极化观察结果的37 GRB的时间集成极化。我们使用他们观察到的光谱参数来做到这一点。在模型中，发射机制是同步辐射，并且假定发射区域的磁场构型被假定为大规模排序。因此，预测的极化度（PDS）是上限。结果。对于大多数由伽马射线爆发偏振仪（GAP），极性和Astrosat检测到的GRB，预测的PD可以匹配相应的观察到的PD。因此，在大规模有序的磁场中，同步器发射模型可以解释由极性和相对较高的PDS（$ \ sim45 \％$）检测到的中等低PD（$ \ sim10 \％$），GAP和Astrosat均观察到。因此，这些GRB提示阶段或峰值时间至少在有序分量的主导下的磁场。然而，由Astrosat观察到的GAP和GRB 180427a观察到的GRB 110721a的PDS均低于观察到的值。由于有序磁场中的同步加速器发射预测了同步加速器发射模型的PD的上限，因此两个爆发的PD观测值挑战了同步加速器发射模型。然后，我们预测即将到来的极性2上的高能极化检测器（HPD）和低能极化探测器（LPD）的PD。在同步加速器发射模型中，HPD检测到的GRB的浓缩PD值将高于LPD，这可能与耗散照相球模型的预测不同。因此，更准确的多播极化观测值高度需要用于GRB及时阶段的测试模型。
Aims. With the accumulation of polarization data in the gamma-ray burst (GRB) prompt phase, polarization models can be tested. Methods. We predicted the time-integrated polarizations of 37 GRBs with polarization observation. We used their observed spectral parameters to do this. In the model, the emission mechanism is synchrotron radiation, and the magnetic field configuration in the emission region was assumed to be large-scale ordered. Therefore, the predicted polarization degrees (PDs) are upper limits. Results. For most GRBs detected by the Gamma-ray Burst Polarimeter (GAP), POLAR, and AstroSat, the predicted PD can match the corresponding observed PD. Hence the synchrotron-emission model in a large-scale ordered magnetic field can interpret both the moderately low PDs ($\sim10\%$) detected by POLAR and relatively high PDs ($\sim45\%$) observed by GAP and AstroSat well. Therefore, the magnetic fields in these GRB prompt phases or at least during the peak times are dominated by the ordered component. However, the predicted PDs of GRB 110721A observed by GAP and GRB 180427A observed by AstroSat are both lower than the observed values. Because the synchrotron emission in an ordered magnetic field predicts the upper-limit of the PD for the synchrotron-emission models, PD observations of the two bursts challenge the synchrotron-emission model. Then we predict the PDs of the High-energy Polarimetry Detector (HPD) and Low-energy Polarimetry Detector (LPD) on board the upcoming POLAR-2. In the synchrotron-emission models, the concentrated PD values of the GRBs detected by HPD will be higher than the LPD, which might be different from the predictions of the dissipative photosphere model. Therefore, more accurate multiband polarization observations are highly desired to test models of the GRB prompt phase.
