XPNAV-1卫星聚焦型X射线脉冲星望远镜在轨稳定性分析  

On-orbit stability analysis of FXPT on XPNAV-1

作　　者：周庆勇[1,2] 闫林丽 李连升 冯来平[1,2] 石永强[4] 孙鹏飞 方柳[1,2] 王龙 ZHOU Qingyong;YAN Linli;LI Liansheng;FENG Laiping;SHI Yongqiang;SUN Pengfei;FANG Liu;WANG Long(Xi’an Institute of Surveying and Mapping,Xi’an 710054,China;State Key Laboratory of Geographic Information Engineering,Xi’an 710054,China;School of Mathematics and Physics,Anhui Jianzhu University,Hefei 230601,China;Beijing Institute of control engineering,Beijing 100090,China;39th Research Institute of China Electronics Technology Corporation,Xi’an 710076,China)

机构地区：[1]西安测绘研究所,西安710054 [2]地理信息工程国家重点实验室,西安710054 [3]安徽建筑大学数理学院,合肥230601 [4]北京控制工程研究所,北京100090 [5]中国电子科技集团公司第三十九研究所,西安710076

出　　处：《航空学报》2023年第3期138-148,共11页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(42004004,42074006,11903001);国家重点基础研究发展计划(2020YFB0505801);安徽省高校省级自然科学研究项目(KJ2019A0787);安徽建筑大学校博士启动基金(2019QDZ14)。

摘　　要：聚焦型X射线脉冲星望远镜(FXPT)是脉冲星导航试验(XPNAV-1)卫星的核心载荷,为中国首款在轨工作的聚焦型X射线望远镜,其在轨稳定性一直备受关注。首先,分析了XPNAV-1卫星对具有特征能谱辐射的超新星遗迹观测数据评估FXPT在轨性能的稳定性的可行性,发现拟合得到的FXPT能量响应参数存在较大误差,且缺乏长期超新星遗迹观测数据,难以支持望远镜在轨性能长期稳定性分析。其次,通过处理分析XPNAV-1卫星于2016年11月―2019年11月间1455次4.1×10^(6)s Crab脉冲星观测数据,发现FXPT在9.5 keV附近长期较稳定地存在大量的X射线光子,且其能量分布曲线近似高斯分布,排除了其来自脉冲星辐射可能性后,推断其来自于FXPT的超上阈信号,同时发现在7.5 keV能量处存在特征谱线辐射,判断其来自于望远镜镜片材料Ni的受激辐射Kα射线。继而提出了一种利用望远镜本征特征能谱和超上阈信号共同监测其在轨稳定性的方法,通过分析近4年XPNAV-1卫星对Crab脉冲星的观测能谱,发现FXPT于2017年10月后性能趋于稳定,该方法有效弥补XPNAV-1卫星无携带辐射标定装置的缺点。同时恢复出Crab脉冲星累积脉冲轮廓,且轮廓形状与RXTE卫星观测结果的相似度为98.6%,FXPT能够精准地获取Crab脉冲星的脉冲轮廓。The Focusing X-ray Pulsar Telescope(FXPT)is the core payload of the first X-ray Pulsar-Based Navigation(XPNAV-1)Satellite.The FXPT is the first focused X-ray telescope in China,and its on-orbit stability has always been concerned.Firstly,the feasibility of using XPNAV-1 observations of supernova remnants with characteristic spectrum radiation to evaluate the on-orbit stability of the FXPT is analyzed.It is found that the fitted FXPT energy response parameters have large errors,and the lack of long-term supernova remnants observations makes it difficult to support the long-term stability analysis of the telescope’s on-orbit performance.Secondly,the 1455 times observations with an exposure time of 4.1×10^(6)s of the Crab Pulsar from the XPNAV-1 from November 2016 to November 2019 are processed and analyzed.It is found that there are a large number of X-ray photons near 9.5 keV in the FXPT for a long time,and their energy distribution curve approximates a Gaussian distribution.After excluding the possibility of radiation from the pulsar,it is inferred that it comes from the signal beyond the upper threshold of FXPT.It is also found that there exists characteristic spectral line radiation at the energy of 7.5 keV,which may come from the stimulated radiation of Ni,the telescope lens material.Then,a method is proposed to monitor the on-orbit stability of telescope by jointly using the its intrinsic characteristic spectrum and the signal beyond the upper threshold.An analysis of the spectrum of the Crab observed by XPNAV-1 Satellite in the past four years shows that the performance of FXPT tends to be stable after October 2017.This method effectively overcomes the shortcoming that XPNAV-1 is not equipped with a radiation calibration device.The integrated pulse profile of the Crab is also recovered and the similarity of this pulse profile with that from RXTE is 98.6%,demonstrating that the FXPT can accurately obtain the pulse profile of the Crab.

关 键 词：聚焦型X射线脉冲星望远镜 脉冲星导航试验(XPNAV-1)卫星 Crab脉冲星 脉冲轮廓 光子能量分布 

分 类 号：V447.1[航空宇航科学与技术—飞行器设计]