We present an analysis of Chandra spectra of five gravitationally lensed active galactic nuclei. We confirm the previous detections of FeK$α$ emission lines in most images of these objects with high significance. The line energies range from 5.8 to 6.8 keV with widths from unresolved to 0.6 keV, consistent with emission close to spinning black holes viewed at different inclination angles. We also confirm the positive offset from the Iwasawa-Taniguchi effect, the inverse correlation between the FeK$α$ equivalent width and the X-ray luminosity in AGN, where our measured equivalent widths are larger in lensed quasars. We attribute this effect to microlensing, and perform a microlensing likelihood analysis to constrain the emission size of the relativistic reflection region and the spin of supermassive black holes, assuming that the X-ray corona and the reflection region, responsible for the iron emission line, both follow power-law emissivity profiles. The microlensing analysis yields strong constraints on the spin and emissivity index of the reflection component for Q2237+0305, with $a > 0.92$ and $n > 5.4$. For the remaining four targets, we jointly constrain the two parameters, yielding $a=0.8\pm0.16$ and an emissivity index of $n=4.0\pm 0.8$, suggesting that the relativistic X-ray reflection region is ultra-compact and very close to the innermost stable circular orbits of black holes, which are spinning at close to the maximal value. We successfully constrain the half light radius of the emission region to $< 2.4$ $r_g$ ($r_g = GM/c^2$) for Q2237+0305 and in the range 5.9--7.4 $r_g$ for the joint sample.
Physically motivated AGN emissivity profiles and their effects on quasar microlensing signatures. 1. Multi-epoch accretion disc size inference
IFPU - Institute for Fundamental Physics of the Universe（基础物理宇宙研究所）；SISSA - International School for Advanced Studies（国际高等研究院）；INAF - Osservatorio Astronomico di Trieste（的里雅斯特天文台）；Center for Astrophysics and Cosmology, University of Nova Gorica（新戈里察大学天体物理学与宇宙学中心）
Test of relativistic gravity using microlensing of relativistically broadened lines in gravitationally lensed quasars
我们表明，在强透镜类星体中观测相对论性加宽的发射线（例如X射线中的Fe K α线）的微透镜效应的时间依赖性，可以提供超大质量黑洞视界附近圆形轨道的天体力学数据。该信息可以从放大线的红/蓝边缘的演化的观察中提取，所述红/蓝边缘刚好在微透镜焦散线穿过最内侧稳定圆形轨道的周期之前和之后。这种演化的函数形式对吸积黑洞和微透镜焦散网络系统的许多天体物理参数不敏感（与全谱线的演化相反）。测量红/蓝边缘的时间演化可以精确测量引力红移和圆形轨道速度的径向依赖性，直到最里面的稳定圆形轨道。这些测量可以用来区分广义相对论和相对论引力的替代模型，其中光子和大质量物体绕引力中心的动力学不同于史瓦西或克尔时空中的测地线。
Constraining Black Hole Natal Kicks with Astrometric Microlensing
多项证据表明，中子星在由坍缩恒星的残余物形成时会受到巨大的撞击。然而，黑洞（BH）是否受到出生踢的证据并不清楚，依赖于对BH X射线双星和大质量失控和逃逸恒星的分析的弱约束。在这里，我们第一次表明，最近的微透镜检测提供了一种新的方法来测量BHS在出生时收到的踢。当黑洞通过光度和天体测量微透镜被识别，并且透镜恒星有已知的距离和自行时，黑洞的质量、距离和自行就可以确定。我们研究了在超新星爆发过程中被破坏的偏心双星的逃逸速度，发现特殊的速度与BH出生时的反冲强烈相关，通常在20%以内，即使出生时的反冲小于轨道速度。因此，通过测量黑洞或其他致密天体的特殊速度，我们实际上是测量了该天体受到的出生反冲。我们专注于MOA-2011-BLG-191/OGLE-2011-BLG-0462，这是一个通过微透镜检测到的孤立的单个BH，并考虑了一系列可能的形成场景，包括其形成于超新星事件期间双星的破坏。我们确定MOA-2011-BLG-191/OGLE-2011-BLG-0462具有与厚盘人口一致的银河系轨道，但如果它是在运动学薄盘中形成的，它会收到出生踢$\lesssim$ 100 km s $^{-1}$。
