分类： 天文学 >> 天文学 提交时间： 2023-02-19
Jiahuan Zhu
Hong Li
Hua Feng
Jiahui Huang
Xiangyun Long
Qiong Wu
Weichun Jiang
Massimo Minuti
Saverio Citraro
Hikmat Nasimi
Dongxin Yang
Jiandong Yu
Ge Jin
Ming Zeng
Peng An
Luca Baldini
Ronaldo Bellazzini
Alessandro Brez
Luca Latronico
Carmelo Sgro
摘要： PolarLight is a space-borne X-ray polarimeter that measures the X-ray polarization via electron tracking in an ionization chamber. It is a collimated instrument and thus suffers from the background on the whole detector plane. The majority of background events are induced by high energy charged particles and show ionization morphologies distinct from those produced by X-rays of interest. Comparing on-source and off-source observations, we find that the two datasets display different distributions on image properties. The boundaries between the source and background distributions are obtained and can be used for background discrimination. Such a means can remove over 70% of the background events measured with PolarLight. This approaches the theoretical upper limit of the background fraction that is removable and justifies its effectiveness. For observations with the Crab nebula, the background contamination decreases from 25% to 8% after discrimination, indicative of a polarimetric sensitivity of around 0.2 Crab for PolarLight. This work also provides insights into future X-ray polarimetric telescopes.
分类： 天文学 >> 天文学 提交时间： 2023-02-19
Jia-Xing Wen
Xu-Tao Zheng
Jian-Dong Yu
Yue-Peng Che
Dong-Xin Yang
Huai-Zhong Gao
Yi-Fei Jin
Xiang-Yun Long
Yi-Hui Liu
Da-Cheng Xu
Yu-Chong Zhang
Ming Zeng
Yang Tian
Hua Feng
Zhi Zeng
Ji-Rong Cang
Qiong Wu
Zong-Qing Zhao
Bin-Bin Zhang
Peng An
摘要： Gamma-Ray Integrated Detectors (GRID) mission is a student project designed to use multiple gamma-ray detectors carried by nanosatellites (CubeSats), forming a full-time all-sky gamma-ray detection network that monitors the transient gamma-ray sky in the multi-messenger astronomy era. A compact CubeSat gamma-ray detector, including its hardware and firmware, was designed and implemented for the mission. The detector employs four Gd2Al2Ga3O12 : Ce (GAGG:Ce) scintillators coupled with four silicon photomultiplier (SiPM) arrays to achieve a high gamma-ray detection efficiency between 10 keV and 2 MeV with low power and small dimensions. The first detector designed by the undergraduate student team onboard a commercial CubeSat was launched into a Sun-synchronous orbit on October 29, 2018. The detector was in a normal observation state and accumulated data for approximately one month after on-orbit functional and performance tests, which were conducted in 2019.
点击量
待评议
点击量
下载量
评论
