The Analogous Structure of Accretion Flows in Supermassive and Stellar Mass Black Holes: New Insights from Faded Changing-look Quasars
The Analogous Structure of Accretion Flows in Supermassive and Stellar Mass Black Holes: New Insights from Faded Changing-look Quasars
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DOI：
10.3847/1538-4357/ab3c1a
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发表时间：
2019-03
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通讯作者：
J. Ruan;S. Anderson;M. Eracleous;P. Green;D. Haggard;C. MacLeod;J. Runnoe;M. Sobolewska
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作者：
J. Ruan;S. Anderson;M. Eracleous;P. Green;D. Haggard;C. MacLeod;J. Runnoe;M. Sobolewska
尽管它们的黑洞质量相差108倍，但有几条证据表明，活动星系核（AGN）和银河系X射线双星中的黑洞吸积流可能相似。然而，目前还不清楚X射线双星中的盘冠系统的几何形状是否直接扩展到活动星系核，以及这种类比是否仍然适用于不同的吸积状态。我们通过比较活动星系核中紫外-X射线光谱指数（αOX）和爱丁顿比与X射线双星爆发观测预测值之间的相关性来检验活动星系核/X射线双星类比。这种方法探测它们的盘冠系统的几何形状，因为它们在不同的吸积状态之间过渡。我们使用新的钱德拉X射线和地基静止紫外线观测褪色的“变化外观”类星体，以扩大这种比较，以较低的爱丁顿比<10−2，其中X射线双星的观测预测活动星系核中的αOX软化。我们发现，活动星系核的αOX和爱丁顿比之间的相关性与原型X射线双星爆发中的吸积态跃迁有着显著的相似性，包括在临界爱丁顿比为100 - 10−2时这种相关性的反转。我们的研究结果表明，黑洞吸积流的结构直接规模在一个因素的108倍的黑洞质量和不同的吸积状态，使我们能够应用X射线双星的理论模型来解释活动星系核现象。
Despite their factor of ∼108 difference in black hole mass, several lines of evidence suggest possible similarities between black hole accretion flows in active galactic nuclei (AGN) and Galactic X-ray binaries. However, it is still unclear whether the geometry of the disk–corona system in X-ray binaries directly scales up to AGN and whether this analogy still holds in different accretion states. We test this AGN/X-ray binary analogy by comparing the observed correlations between the UV–to–X-ray spectral index (αOX) and Eddington ratio in AGN to those predicted from observations of X-ray binary outbursts. This approach probes the geometry of their disk–corona systems as they transition between different accretion states. We use new Chandra X-ray and ground-based rest-UV observations of faded “changing-look” quasars to extend this comparison to lower Eddington ratios of <10−2, where observations of X-ray binaries predict a softening of αOX in AGN. We find that the observed correlations between the αOX and Eddington ratio of AGN displays a remarkable similarity to accretion state transitions in prototypical X-ray binary outbursts, including an inversion of this correlation at a critical Eddington ratio of ∼10−2. Our results suggest that the structures of black hole accretion flows directly scale across a factor of ∼108 in black hole mass and across different accretion states, enabling us to apply theoretical models of X-ray binaries to explain AGN phenomenology.