论文标题
硬X射线揭示的Cygnus X-1的不同积聚模式
Distinct accretion modes of Cygnus X-1 revealed from hard X-rays
论文作者
论文摘要
多亏了对黑洞二进制CYG X-1的反复观察，在15年内进行了整体卫星，该卫星收集了该来源的硬X射线频段中最大的数据集。我们已经分析了这些数据，并由其他X射线卫星和15 GHz的无线电通量收集的数据补充。为了表征系统的光谱和可变性属性，我们检查了参数，例如硬X射线通量，光子指数和分数变异性。我们的主要结果是，针对22-100 keV带的光子指数和通量的2D分布形成六个簇。该结果在构造场景中解释为负责硬X射线发射的主要过程，得出的结论是，CYG X-1中的热等离子体采用了六个特定的几何形式。这些等离子体态的不同特征通过其不同的X射线和无线电变异模式加强。特别是，最坚硬，最柔软的等离子体状态没有其他四个状态的短期通量 - 光子指数相关性，这意味着血浆和积聚磁盘之间缺乏相互作用。该系统在这两个极端状态之间演变，光谱斜率由磁盘光子对等离子体的可变冷却调节。
Thanks to recurrent observations of the black hole binary Cyg X-1 carried out over 15 years the INTEGRAL satellite has collected the largest data set in the hard X-ray band for this source. We have analyzed these data, complemented by data collected by other X-ray satellites and radio flux at 15 GHz. To characterize the spectral and variability properties of the system we have examined parameters such as the hard X-ray flux, photon index and fractional variability. Our main result is that the 2D distribution of the photon index and flux determined for the 22-100 keV band forms six clusters. This result, interpreted within the Comptonization scenario as the dominant process responsible for the hard X-ray emission, leads to a conclusion that the hot plasma in Cyg X-1 takes the form of six specific geometries. The distinct character of each of these plasma states is reinforced by their different X-ray and radio variability patterns. In particular, the hardest and softest plasma states show no short-term flux - photon index correlation typical for the four other states, implying a lack of interaction between the plasma and accretion disk. The system evolves between these two extreme states, with the spectral slope regulated by a variable cooling of the plasma by the disk photons.
