Long-term evolution of the X-ray flux of the Crab pulsar  

作　　者：Hai-Sheng Zhao Ming-Yu Ge Xiao-Bo Li Lin-Li Yan You-Li Tuo Fang-Jun Lu Li-Ming Song Cong-Zhan Liu Shu Zhang Shuang-Nan Zhang 

机构地区：[1]Key Laboratory for Particle Astrophysics,Institute of High Energy Physics,Chinese Academy of Sciences,19B Yuquan Road,Beijing 100049,China [2]School of Mathematics and Physics,Anhui JianZhu University,Hefei 230601,Anhui,China

出　　处：《Radiation Detection Technology and Methods》2023年第1期48-55,共8页辐射探测技术与方法（英文）

基　　金：support from the National Program on Key Research and Development Project(Grant No.2021YFA0718500)from the Minister of Science and Technology of China(MOST);supports from the National Natural Science Foundation of China under Grants U1938102,12273043,U1838201,U1838202,U1938109 and U1938108;supported by International Partnership Program of Chinese Academy of Sciences(Grant No.113111KYSB20190020).

摘　　要：Purpose In order to carry out in-orbit calibration,the hard X-ray modulation telescope satellite(HXMT)has made a number of observations of Crab pulsar.We study the long-term evolution of the X-ray flux of the Crab pulsar with these observational data.Methods We use nearly four years Crab pulsar’s data obtained by HXMT and the neutron star interior composition of explorer to test whether L_(x)∝L_(sd)^(α) holds for an individual pulsar,where L_(x) is the pulsed X-ray luminosity and Lsd is its spin-down luminosity.We also combine the earlier results obtained with PCA and HEXTE data(Yan et al.in ApJ 865:21,2018)to get the long-term evolution characteristics of the Crab pulsar.Results We find the X-ray flux evolution can be fitted by a linear correlation:L_(x)∝L_(sd)^(1.42±0.18).In soft X-ray energy band(1–10 keV)and hard X-ray energy band(27–250 keV),αdoes not change significantly with either energy or phase.However,this will need to be confirmed in future.For example,the interpulse component of hard X-ray may follow L_(x)∝L_(sd)^(0.96±0.34),which may be different from the correlation of soft X-rays and main pulse component.On the other hand,the hard X-ray flux evolution shows that the performance of high energy X-ray telescope(HE)onboard HXMT,such as effective area,is stable.Conclusion We conclude that the X-ray luminosity of the Crab pulsar closely correlates with its spin-down luminosity.However,the emission mechanism responsible for these phenomena remains not fully understood.

关 键 词：X-rays Crab pulsar Flux evolution Spin-down luminosity 

分 类 号：TL7[核科学技术—辐射防护及环境保护]