论文标题
极性伽马射线爆发极化目录
The POLAR Gamma-Ray Burst Polarization Catalog
论文作者
论文摘要
尽管进行了50多年的研究,但关于GRB的起源和性质仍然存在许多公开问题。长期以来,人们认为这些极端现象的迅速排放的极化测量一直被认为是回答这些问题范围的关键。极地检测器旨在在大约50-500 keV的能量范围内生成第一组详细且可靠的极化测量值。在2016年底和2017年初,Polar检测到总共55个GRB。过去已经报道了其中5个GRB的分析结果。发现结果与低或非极化通量一致。但是,其他合作的先前报告发现了高度的两极分化。我们研究了极性观察到的所有14个GRB的极化,从统计上稳健的推论是可能的。此外,对具有足够明显通量的GRB进行了时间分辨的极化研究。在3ML框架内开发的一种公开可用的极化分析工具用于产生统计上强大的结果。该方法允许将光谱和极化数据与来自Fermi GBM和Swift-Bat的光谱数据相结合,以共同对光谱和极化参数进行建模。时间综合分析发现所有结果与低或零极化与警告的兼容,即当在单个脉冲中进行时间分辨分析时,我们会观察到中度极化,并快速变化的极化角度。因此,时间集成极化的结果,同时指向较低的极化是在变化的极化信号上的求和的可能性,从而消除了真正的中度极化。因此,我们警告不要过度解释任何时间融合的结果,并鼓励人们等待即将到来的任务(例如Polar-2和LEAP)进行更详细的极化测量。
Despite over 50 years of research, many open questions remain about the origin and nature of GRBs. Polarization measurements of the prompt emission of these extreme phenomena have long been thought to be the key to answering a range of these questions. The POLAR detector was designed to produce the first set of detailed and reliable polarization measurements in an energy range of approximately 50-500 keV. During late 2016 and early 2017, POLAR detected a total of 55 GRBs. Analysis results of 5 of these GRBs have been reported in the past. The results were found to be consistent with a low or unpolarized flux. However, previous reports by other collaborations found high levels of polarization. We study the polarization for all the 14 GRBs observed by POLAR for which statistically robust inferences are possible. Additionally, time-resolved polarization studies are performed on GRBs with sufficient apparent flux. A publicly available polarization analysis tool, developed within the 3ML framework, was used to produce statistically robust results. The method allows to combine spectral and polarimetric data from POLAR with spectral data from the Fermi GBM and Swift-BAT to jointly model the spectral and polarimetric parameters. The time integrated analysis finds all results to be compatible with a low or zero polarization with the caveat that, when time-resolved analysis is possible within individual pulses, we observe moderate polarization with a rapidly changing polarization angle. Thus, time-integrated polarization results, while pointing to lower polarization are potentially an artifact of summing over the changing polarization signal and thus, washing out the true moderate polarization. Therefore, we caution against over interpretation of any time-integrated results and encourage one to wait for more detailed polarization measurements from forthcoming missions such as POLAR-2 and LEAP.