论文标题
建模X射线RMS Spectra II：PDS 456的超快速流出
Modelling X-ray RMS spectra II: the ultra-fast outflow of PDS 456
论文作者
论文摘要
We present an improved model for excess variance spectra describing ultra-fast outflows and successfully apply it to the luminous (L ~ 10^47 erg/s) low-redshift (z = 0.184) quasar PDS 456. The model is able to account well for the broadening of the spike-like features of these outflows in the excess variance spectrum of PDS 456, by considering two effects: a correlation between the outflow速度和对数X射线通量和固有的多普勒宽阔的v_int = 10^4 km/s。通过从蒙特卡洛模拟中计算计数光谱的分数过剩方差来生成模型。我们发现证据表明，PDS 456中的流出是结构化的，即存在两个或多个层，流速度为0.27-0.30 C，0.41-0.49 C和0.15-0.20 c，对于可能的第三层，这与文献一致。我们讨论了通常适用于过度方差光谱的普遍适用模型的前景，以检测超快速流出并研究其结构。我们提供了流出速度与对数X射线通量之间相关性强度的估计值，并研究了其有效性。
We present an improved model for excess variance spectra describing ultra-fast outflows and successfully apply it to the luminous (L ~ 10^47 erg/s) low-redshift (z = 0.184) quasar PDS 456. The model is able to account well for the broadening of the spike-like features of these outflows in the excess variance spectrum of PDS 456, by considering two effects: a correlation between the outflow velocity and the logarithmic X-ray flux and intrinsic Doppler broadening with v_int = 10^4 km/s. The models were generated by calculating the fractional excess variance of count spectra from a Monte Carlo simulation. We find evidence that the outflow in PDS 456 is structured, i.e., that there exist two or more layers with outflow velocities 0.27-0.30 c, 0.41-0.49 c, and 0.15-0.20 c for a possible third layer, which agrees well with the literature. We discuss the prospects of generally applicable models for excess variance spectra for detecting ultra-fast outflows and investigating their structure. We provide an estimate for the strength of the correlation between the outflow velocity and the logarithmic X-ray flux and investigate its validity.
