Soft gamma-ray polarimetry with COSI using maximum likelihood analysis
Soft gamma-ray polarimetry with COSI using maximum likelihood analysis
复制标题
使用 COSI 使用最大似然分析进行软伽马射线偏振测量
DOI：
10.1007/978-981-16-4544-0_145-1
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
A. Zoglauer
中科院分区：
文献类型：
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作者：
J. Tomsick;A. Lowell;Hadar Lazar;C. Sleator;A. Zoglauer
对来自恒星、吸积黑洞和伽马射线暴（GRB）的高能发射的线性偏振的测量提供了限制发射机制和几何形状（例如，吸积盘、喷流、磁场等）在源。对于软（MeV）伽马射线波段的光子，康普顿散射是探测器中最有可能发生的相互作用。康普顿望远镜探测到单个入射光子的多重相互作用，从而可以测量散射角。在从源检测到许多光子之后，方位角的分布提供偏振信息。虽然标准方法依赖于对光子进行分箱以产生和拟合方位角散射角分布，但是通过使用附加信息来更准确地加权每个事件对似然统计的贡献来获得改进的偏振灵敏度。在本章中，我们将介绍康普顿光谱仪和成像仪（COSI）及其偏振测量功能。我们还描述了最大似然技术，它的应用COSI数据分析，并计划其未来的使用。
Measurements of the linear polarization of high-energy emission from pulsars, accreting black holes, and gamma-ray bursts (GRBs) provide an opportunity for constraining the emission mechanisms and geometries (e.g., of the accretion disk, jet, magnetic field, etc.) in the sources. For photons in the soft (MeV) gamma-ray band, Compton scattering is the most likely interaction to occur in detectors. Compton telescopes detect multiple interactions from individual incoming photons, allowing for scattering angles to be measured. After many photons are detected from a source, the distribution of azimuthal angles provides polarization information. While the standard method relies on binning the photons to produce and fit an azimuthal scattering angle distribution, improved polarization sensitivity is obtained by using additional information to more accurately weight each event’s contribution to the likelihood statistic. In this chapter, we describe the Compton Spectrometer and Imager (COSI) and its capabilities for polarization measurements. We also describe the maximum likelihood technique, its application to COSI data analysis, and plans for its future use.