Searching for energy-resolved quasi-periodic oscillations in AGN
Searching for energy-resolved quasi-periodic oscillations in AGN
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DOI：
10.1093/mnras/staa4024
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发表时间：
2021-01
影响因子：
4.8
通讯作者：
Dominic I Ashton;M. Middleton
中科院分区：
文献类型：
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作者：
Dominic I Ashton;M. Middleton
活动星系核（AGN）中的x射线准周期振荡（QPOs）使我们能够探测和理解高度弯曲时空中吸积的本质，然而迄今为止，最强大的探测形式（即多次观测的重复探测）仅限于单一来源，只有几个其他的单一观测探测的初步声明。这些已建立的AGN QPOs与特定光谱成分的关联促使我们搜索XMM-Newton档案并分析38个明亮AGN的能量分辨光曲线。我们应用了一个保守的虚警测试程序，折叠了底层宽带噪声的不确定性和协方差。我们还探讨了红噪声泄漏的影响，以及对潜在宽带噪声的各种不同形式（幂律、破幂律和洛伦兹）的假设。在这项初步研究中，我们从38个样本中报告了6个agn中的QPO候选者（7个包括MRK 766中的一个暂定检测），这些候选者往往以特征能量被发现，在4个案例中，在至少两次观测中以相同的频率被发现，这表明它们在本质上极不可能是假的。
X-ray quasi-periodic oscillations (QPOs) in active galactic nucleus (AGN) allow us to probe and understand the nature of accretion in highly curved space–time, yet the most robust form of detection (i.e. repeat detections over multiple observations) has been limited to a single source to-date, with only tentative claims of single observation detections in several others. The association of those established AGN QPOs with a specific spectral component has motivated us to search the XMM–Newton archive and analyse the energy-resolved light curves of 38 bright AGNs. We apply a conservative false alarm testing routine folding in the uncertainty and covariance of the underlying broad-band noise. We also explore the impact of red-noise leak and the assumption of various different forms (power-law, broken power-law, and Lorentzians) for the underlying broad-band noise. In this initial study, we report QPO candidates in six AGNs (seven including one tentative detection in MRK 766) from our sample of 38, which tend to be found at characteristic energies and, in four cases, at the same frequency across at least two observations, indicating they are highly unlikely to be spurious in nature.