论文标题
关于黑洞系统Maxi J1535-571中QPO现象的能量依赖性
On the energy dependence of the QPO phenomenon in the black hole system MAXI J1535-571
论文作者
论文摘要
对黑洞系统最大J1535-571的Astrosat观测值的先前分析表明，存在强烈的准周期振荡（QPO），其频率与高能量光谱指数相关。在这里，我们拟合了从截短的圆盘上发出的光谱，并带有内部热的电晕，研究QPO频率依赖于其他光谱参数，并对QPO的能量依赖性r.m.s和QPO的时间延迟进行建模，以识别其变化负责QPO的物理光谱参数。发现QPO频率也与散射分数（即，构成的软光子的比例）相关，并且其对吸积率和内盘半径的依赖性与动态频率一致。硬性光子和软光子之间的时间段对于QPO频率> 2.2 Hz为阴性，对于较小的值是阳性的，这使得这是在GRS 1915+105之后显示这种行为的第二个黑洞系统。建模依赖能量的时间延迟和R.M.S需要使吸积率，内盘半径和冠状加热速率的相关变化，而与其他两个小于2.2 Hz的QPO频率相比，后者具有时间延迟，而QPO频率小于<2.2 Hz，哪些会更改符号（即，冠状加热率更高的值）。讨论了结果的含义。
Previous analysis of AstroSat observations of the black hole system MAXI J1535-571, have revealed the presence of a strong Quasi-Periodic Oscillation (QPO) whose frequency is correlated with the high energy spectral index. Here, we fit the spectra as emitted from a truncated disc with an inner hot corona, study the QPO frequency dependence on other spectral parameters and model the energy dependent r.m.s and time-lag of the QPO to identify the physical spectral parameters whose variation are responsible for the QPO. The QPO frequency is found to also correlate with the scattering fraction (i.e. the fraction of the soft photons Comptonized) and its dependence on the accretion rate and inner disc radii is consistent with it being the dynamical frequency. The time-lag between the hard and soft photons is negative for QPO frequency > 2.2 Hz and is positive for lesser values, making this the second black hole system to show this behaviour after GRS 1915+105. Modelling the energy dependent time-lag and r.m.s requires correlated variation of the accretion rate, inner disc radii and the coronal heating rate, with the latter having a time-lag compared to the other two for QPO frequencies less than < 2.2 Hz and which changes sign (i.e. the coronal heating variation precedes the accretion rate one) for higher values. The implications of the results are discussed.
