黑洞候选体X射线双星Cyg X-1长期谱变化的研究  

The Study of the Long-Term Spectral Variability of Cyg X-1 with Rossi X-ray Timing Explorer

作　　者：董爱军[1] 王建成[2] 薛力[3] 

机构地区：[1]滁州学院,滁州239000 [2]中国科学院国家天文台/云南天文台,昆明650011 [3]厦门大学,厦门361005

出　　处：《天文学报》2009年第1期1-14,共14页Acta Astronomica Sinica

基　　金：滁州学院科研(2007ky045)资助项目

摘　　要：利用Rossi X-ray Timing Explorer(RXTE)卫星从1996年1月5日到2005年5月1日的all-sky monitor(ASM,1.5—12KeV)资料,详细分析了黑洞候选体X射线双星Cyg X-1在A-band(1.5—3KeV),B-band(3—5KeV)和C-band(5—12KeV)三个能段上光子计数率与谱线硬度比HR2(5——12KeV/3——5KeV)的相关性.利用1天时标的ASM资料研究发现,(1)Cyg X-1处于软态时,在A-band上光子计数率与硬度比HR2呈现反相关性,而在B-band和C-band上呈现正相关性.当该天体处于硬态时,在A、B、C三个能段上光子计数率与硬度比HR2都是反相关的.(2)Cyg X-1处于硬态和软态时,硬度比HR2与HR1都是正相关的.此外,还分析了ASM上"Dwell by Dwell"资料,得到了十分有趣的结果,即:(1)MJD=52600—52760期间(此时Cyg X-1处于硬态),A-band和B-band上的光子计数率与HR2是反相关性的,而在C-band上却呈现出较强的正相关性.(2)硬态时,硬度比HR2与HR1存在明显的反相关性.We present a comprehensive analysis of extensively studied black hole X- ray binary Cyg X-1 with the observation of Rossi X-ray Timing Explorer all-sky monitor （ASM,1.5--12KeV） from January 1996 to May 2005 and analyze the correlation of Photon Counts rate and hardness ratio HR2（5--12KeV/3-5KeV）. At first, we analyze the ASM data on one-day time scale and find： （1） When Cyg X-1 is in soft state, the correlation of Photon Counts rate to HR2 is negative in A-band（1.5--3KeV） and are positive in B- band（3--5KeV） and C-band（5--12KeV）. （2）The correlation of Photon Counts rate to HR2 are all negative in A-band（1.5--3KeV）, B-band（3--5KeV） and C-band（5--12KeV） in hard state. （3） The correlation of hardness ratio of HR2 to HR1 on one-day time scale are both positive in soft state and hard state. At the same time, we also analysis the spectral vari- ability using the ASM data on ＂Dwell by Dwell＂ time scale, and find a ＇new＇ and interesting correlation, that is： （1） The correlation of Photon Counts rate to hardness ratio HR2 are both negative in A-band and B-band, but is positive in C-band during MJD= 52600- 52760. （2） The correlation of HR2 to HR1 is negative when Cyg X-1 is in hard state.

关 键 词：物理数据与过程:黑洞物理 x一射线:双星 x一射线:个别 

分 类 号：P172[天文地球—天文学]