发表机构
Scuola Universitaria Superiore IUSS Pavia; Department of Physics and Astronomy, University of Southampton; Centre for Extragalactic Astronomy, Durham University, Dept of Physics, South Road, Durham DH1 3LE, UK（帕维亚高等大学学院; 南安普顿大学物理与天文系; 达勒姆大学河外天文学中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究对两个超亮X射线源（NGC 5204 X-1 和 NGC 55 ULX-1）进行时变分析，发现显著的自转周期，并约束吸积盘尺度与结构。
AI 中文摘要
超亮X射线源（ULXs）的本质笼罩在神秘之中，因为它们被认为是光度超过经典爱丁顿极限（对于10$M_{\odot}$黑洞（BH））的点源，但通常被归类为超爱丁顿X射线双星。对混响延迟和延迟-能量谱的研究为光学厚、超爱丁顿盘中的粘性湍流性质提供了一些见解，并且与多波长谱和协方差谱的建模结合使用时很有用。在本研究中，我们关注两个经典上不同的ULXs的时变特性：NGC 5204 X-1 和 NGC 55 ULX-1，两者均已知发射相对论性风，如通过光致电离模型（如SPEX）对发射线谱进行建模所观察到的，但由于其X射线连续谱的硬度比差异，被认为以略微不同的倾角被观测。在这里，我们对这两个ULXs进行了广泛的时变研究，以揭示对吸积盘尺寸尺度和结构的新约束。我们还进行了加速的脉动搜索（包括对信号轨道调制的校正），以发现NGC 5204 X-1 和 NGC 55 ULX-1 中显著的旋转周期性（置信度 > 3$\sigma$）。
英文摘要
The nature of ultra-luminous X-ray sources (ULXs) is shrouded in mystery as they're believed to be point sources with luminosities above the classical Eddington limit for a 10$M_{\odot}$ black hole (BH), but generally fit into the classification tree of super-Eddington X-ray binaries. Studies of reverberation lags and lag-energy spectra provide some insight into the nature of viscous turbulence in optically thick, super-Eddington discs, and are useful in conjunction with modelling multi-wavelength spectra and covariance spectra. In this study, we focus on the timing properties of two classically distinct ULXs: NGC 5204 X-1 and NGC 55 ULX-1, both of which are known to emit relativistic winds, as observed by modelling emission line spectra with photo-ionisation models such as SPEX, but are thought to be viewed at slightly different inclinations due to differences in the hardness-ratio of their X-ray continuum. Here, we perform an extensive timing study of the two ULXs to reveal new constraints on the accretion disc size scale and structure. We also perform an accelerated search for pulsations (including the correction for an orbital modulation of the signal) to discover significant spin-periodicities in both NGC 5204 X-1 and NGC 55 ULX-1 (at $> 3σ$ significance).
Comments25 pages and 24 Figures; comments welcome
