论文标题
极地观察到的螃蟹脉冲星的伽马射线极化
Gamma-Ray Polarimetry of the Crab Pulsar Observed by POLAR
论文作者
论文摘要
据信，螃蟹/星云的X/$γ$射线极化法可以在其发射模型上保存重要信息。过去，几项任务显示了螃蟹发射两极分化的证据。但是，这些测量值的重要性仍然有限。因此，需要新的测量。 Polar是一个广阔的视野，在船上是中国超级飞船Tiangong-2的圆形偏光仪（对50-500 KEV的敏感），该数据从2016年9月到2017年4月获取了数据。尽管并非旨在对Pulsars进行两极分化的测量，但我们在这里提出了一种新颖的方法，它可以应用于Polare以及其他视野的PolariMeterers of Polarimetersers的新方法。具有极性蟹脉冲观测的新型极性关节拟合方法使我们能够获得脉冲星成分的约束测量值。平均阶段间隔的最佳拟合值和相应的1 $σ$偏差：（pd = $ 14 \ etack {+15 \\ -10} $ \％，pa = $ 108 \替换{+33 \\ -54} pa = $ 174 \替代{+39 \\ -36} ^{\ circ} $），对于峰值2 ：（ pd = $ 16 \ orperack {+16 \\ -11} $ \％，pa = $ 78 \ setack {+39 \ \ \ \ \ \ \ \ \ \ \ -30} ^{ ^{\ crive} $）此外，极化度的3 $σ$上限是平均相位间隔（55 \％），峰值1（66 \％）和峰值2（57 \％）。最后，为了说明将来这种方法的能力，我们对具有Polar-2的螃蟹脉冲星进行了两年的观察。结果表明，如果螃蟹Pulsar分别为$ 20 \％$和$ 10 \％$，则Polar-2能够确认以$5σ$和4σ$置信度的两极化的排放。
The X/$γ$ ray polarimetry of the Crab pulsar/nebula is believed to hold crucial information on their emission models. In the past, several missions have shown evidence of polarized emission from the Crab. The significance of these measurements remains however limited. New measurements are therefore required. POLAR is a wide Field of View Compton-scattering polarimeter (sensitive in 50-500 keV) onboard the Chinese spacelab Tiangong-2 which took data from September 2016 to April 2017. Although not designed to perform polarization measurements of pulsars, we present here a novel method which can be applied to POLAR as well as that of other wide Field of View polarimeters. The novel polarimetric joint-fitting method for the Crab pulsar observations with POLAR, allows us to obtain constraining measurements of the pulsar component. The best fitted values and corresponding 1$σ$ deviations for the averaged phase interval: (PD=$14\substack{+15 \\ -10}$\%, PA=$108\substack{+33 \\ -54} ^{\circ}$), for Peak 1: (PD=$17\substack{+18 \\ -12}$\%, PA=$174\substack{+39 \\ -36} ^{\circ}$) and for Peak 2: (PD=$16\substack{+16 \\ -11}$\%, PA=$78\substack{+39 \\ -30} ^{\circ}$). Further more, the 3$σ$ upper limits on the polarization degree are for the averaged phase interval (55\%), Peak 1 (66\%) and Peak 2 (57\%). Finally, to illustrate the capabilities of this method in the future, we simulated two years observation to the Crab pulsar with POLAR-2. The results show that POLAR-2 is able to confirm the emission to be polarized with $5σ$ and $4σ$ confidence level if the Crab pulsar is polarized at $20\%$ and $10\%$ respectively.
