论文标题
Cygnus X-1中的块状风积聚
Clumpy wind accretion in Cygnus X-1
论文作者
论文摘要
Cygnus X-1是观察到的最明亮的X射线源之一，在软X射线和硬X射线中显示了从毫秒到几个月的时间尺度上的X射线强度变化。据信，由于二进制伴侣HDE-226868聚焦的恒星风，因此被认为是在黑洞上的积聚。我们旨在了解负责在硬/低状态下源的短时间X射线变异性（$ <$ 100 s）的物理机制。我们计算低角度动量吸积流的2D相对论流体动力学模拟，其依赖的外边界条件反映了此X射线二进制系统中超级巨人的聚焦，块状风。我们遵循大约100 s的模型的动态演化，并提出结果显示振荡性休克，这是对硬X射线中观察到的可变性的潜在解释。具有冲击溶液的模拟模型与观察到的源的功率密度光谱非常吻合。
Cygnus X-1 is one of the brightest X-ray sources observed and shows the X-ray intensity variations on time scales from milliseconds to months in both the soft and hard X-rays. The accretion onto the black hole is believed to be wind fed due to focused stellar wind from the binary companion HDE-226868. We aim to understand the physical mechanism responsible for the short timescale X-ray variability ($<$100 s) of the source in its Hard/Low state. We compute the 2D relativistic hydrodynamic simulation of the low angular momentum accretion flow with a time dependent outer boundary condition that reflects the focused, clumpy wind from the super-giant in this X-ray binary system. We follow the dynamical evolution of our model for about 100 s and present the results showing an oscillatory shock, being a potential explanation of variability observed in hard X-rays. The simulated model with shock solutions is in good agreement with the observed power density spectra of the source.
