标题： Swift J1753.5-0127：通过频率分辨光谱理解吸积几何结构 显示英文标题

标题： Swift J1753.5-0127 : Understanding the accretion geometry through frequency resolved spectroscopy

摘要： 黑洞双星源Swift J175.5-0127在爆发期间持续了$\sim$12年，从2005年5月到2017年4月。在爆发的大部分时间里，该源保持在低硬态（LHS），仅在爆发末期短暂地过渡到更软的状态。准周期振荡（QPOs）仅在衰减阶段的功率密度谱（PDS）中被观测到。在LHS中，需要一个软热成分来模拟光谱，这与普遍接受的盘截断理论不符。在这项工作中，我们尝试通过使用频率分辨光谱（FRS）研究QPO变化来获得吸积盘几何结构的更清晰图像。我们获得了明亮硬态下的源QPO均方根谱，并用物理成分对其进行建模。我们发现，QPO均方根谱只能由康普顿化成分描述，而没有来自热盘的贡献。这表明在PDS中观测到的变化起源于康普顿化成分，QPOs的演化可能是由于变化定位到热内流的不同半径，而不是盘截断。盘参数的最小变化也表明在整个爆发期间存在一个稳定的盘。 显示英文摘要

摘要： The Black Hole Binary source Swift J175.5-0127 remained in outburst for $\sim$ 12 years from May 2005 to April 2017. For most part of the outburst, the source remained in the Low Hard State (LHS) displaying transitions to softer states only towards the end of the outburst for short periods of time. Quasi periodic Oscillations (QPOs) were observed in the Power Density Spectrum (PDS) only during the decay. A soft thermal component was required to model the spectrum in LHS, which does not conform to the generally accepted disc truncation theory. In this work, we attempt to obtain a clearer picture of the accretion disc geometry by studying the QPO variability using frequency resolved spectroscopy (FRS). We obtain the QPO rms spectrum of the source during the bright-hard state and model it with physical components. We find that the QPO rms spectrum can be described only by a Comptonisation component with no contribution from the thermal disc. This indicates that the variability observed in the PDS originates in the Comptonisation component and the evolution of the QPOs is likely to be a result of localization of the variabilities to different radii of the hot inner flow rather than disc truncation. The minimal variation in disc parameters also points to the existence of a stable disc throughout the outburst.