Theoretical modelling of the AGN iron-line vs continuum time-lags in the lamp-post geometry
Theoretical modelling of the AGN iron-line vs continuum time-lags in the lamp-post geometry
复制标题
AGN 铁线与灯柱几何连续体时滞的理论建模
DOI：
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复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
I. McHardy
中科院分区：
文献类型：
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作者：
A. Epitropakis;I. Papadakis;I. Papadakis;M. Dovčiak;T. Pecháček;D. Emmanoulopoulos;D. Emmanoulopoulos;V. Karas;I. McHardy
内容：在Fe K$\alpha$发射和X射线连续体的变化之间的时间滞后的理论建模可能会揭示在活动星系（AGN）和X射线双星的X射线发射区域的物理和几何形状。本文给出了对七个X射线明亮和可变活动星系核的两个能带变化之间的时滞（5 -7$ vs 2 - 4\，\keV\$）进行系统分析的结果。
目的：我们尽可能准确地估计时滞，并在灯柱几何形状的背景下用理论模型拟合它们。我们还限制了活动星系核中X射线发射区的几何形状。
研究方法：我们使用了所有可用的XMM-Newton源数据，并提取了5 -7$和2 - 4keV $能量带的光变曲线。我们使用这些光变曲线，并应用经过彻底测试（通过广泛的数值模拟）的配方来估计具有最小偏差的时滞，近似遵循高斯分布，并且具有已知误差。使用传统的最小化技术，然后我们用两种不同的模型拟合观察到的时滞：一种现象学模型，其中时滞对频率具有幂律依赖性，以及一种物理模型，使用灯柱几何形状中预期的混响时滞。后者的计算假设一个点状的初级X射线源以上的黑洞所包围的中性吸积盘与太阳铁丰度。我们考虑了各种X射线源高度、倾斜角和黑洞自旋值的所有相对论效应。
Context: Theoretical modelling of time-lags between variations in the Fe K$\alpha$ emission and the X-ray continuum might shed light on the physics and geometry of the X-ray emitting region in active galaxies (AGN) and X-ray binaries. We here present the results from a systematic analysis of time-lags between variations in two energy bands ($5-7$ vs $2-4\,\mathrm{keV}$) for seven X-ray bright and variable AGN.
Aims: We estimate time-lags as accurately as possible and fit them with theoretical models in the context of the lamp-post geometry. We also constrain the geometry of the X-ray emitting region in AGN.
Methods: We used all available archival \textit{XMM-Newton} data for the sources in our sample and extracted light curves in the $5-7$ and $2-4\,\mathrm{keV}$ energy bands. We used these light curves and applied a thoroughly tested (through extensive numerical simulations) recipe to estimate time-lags that have minimal bias, approximately follow a Gaussian distribution, and have known errors. Using traditional $\chi^2$ minimisation techniques, we then fitted the observed time-lags with two different models: a phenomenological model where the time-lags have a power-law dependence on frequency, and a physical model, using the reverberation time-lags expected in the lamp-post geometry. The latter were computed assuming a point-like primary X-ray source above a black hole surrounded by a neutral and prograde accretion disc with solar iron abundance. We took all relativistic effects into account for various X-ray source heights, inclination angles, and black hole spin values.
影响因子：
4.8
作者：
W. Alston;S. Vaughan;P. Uttley
通讯作者：
W. Alston;S. Vaughan;P. Uttley
DOI：
10.1111/j.1365-2966.2006.10871.x
发表时间：
2006-07
影响因子：
4.8
作者：
P. Arévalo;I. Papadakis;P. Uttley;I. McHardy;W. Brinkmann
通讯作者：
P. Arévalo;I. Papadakis;P. Uttley;I. McHardy;W. Brinkmann