The Width-Flux Relation of the Broad Iron KαLine during the State Transitions of the Black Hole X-Ray Binaries  

作　　者：Hang-Ying Shui Fu-Guo Xie Zhen Yan Ren-Yi Ma 

机构地区：[1]Department of Astronomy and Institute of Theoretical Physics and Astrophysics,Xiamen University,Xiamen 361005,China [2]SHAO-XMU Joint Center for Astrophysics,Xiamen 361005,China [3]Key Laboratory for Research in Galaxies and Cosmology,Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030,China

出　　处：《Research in Astronomy and Astrophysics》2023年第6期220-227,共8页天文和天体物理学研究（英文版）

基　　金：supported in part by the National Natural Science Foundation of China under Grant Nos.U2038108,12192220,12192223 and 12133008;the National SKA Program of China(No.2020SKA0110102);supported in part by the Youth Innovation Promotion Association of CAS(Y202064)。

摘　　要：The observations of varying broad iron lines during the state transition of the black hole X-ray binaries have been accumulating.In this work,the relation between the normalized intensity and the width of iron lines is investigated,in order to understand better the variation of iron lines and possibly its connection to state transition.Considering the uncertainties due to ionization and illuminating X-rays,only the effects of geometry and gravity are taken into account.Three scenarios were studied,i.e.,the continuous disk model,the innermost annulus model,and the cloud model.As shown by our calculations,at given iron width,the line flux of the cloud model is smaller than that of the continuous disk model;while for the innermost annulus model,the width is almost unrelated with the flux.The range of the line strength depends on both the BH spin and the inclination of the disk.We then apply to the observation of MAXI J1631-479 by Nuclear Spectroscopic Telescope Array during its decay from the soft state to the intermediate state.We estimated the relative line strength and width according to the spectral fitting results in Xu et al.,and then compared with our theoretical width-flux relation.It was found that the cloud model was more favored.We further modeled the iron line profiles,and found that the cloud model can explain both the line profile and its variation with reasonable parameters.

关 键 词：ACCRETION accretion disks black hole physics X-rays:binaries 

分 类 号：P145.8[天文地球—天体物理]