GRS 1915+105中观测到的准周期振荡的复杂能量依赖行为
Complex Energy-Dependent Behaviour of Quasi-Periodic Oscillation Observed in GRS 1915+105
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中文总结 AI 辅助
本研究利用AstroSat的LAXPC数据，发现GRS 1915+105的QPO能量依赖演化源于两个不同洛伦兹分量，而非时间变异性驱动，相关结果完善了黑洞X射线双星的QPO特性研究。
中文摘要 AI 辅助
我们利用AstroSat卫星搭载的LAXPC仪器的观测数据，呈现了黑洞X射线双星GRS 1915+105中准周期振荡（QPO）的复杂能量分辨特性。在多个能段中构建功率密度谱（PDS），并使用多洛伦兹分量进行建模，以研究QPO特性的能量依赖关系。QPO频率随能量呈现适度增加的趋势。动态PDS分析未揭示QPO频率随时间演化的明确证据，表明观测到的频率偏移并非主要由时间变异性驱动。我们对能量分辨PDS进行同时拟合，发现将QPO特征描述为两个洛伦兹分量的模型拟合效果更优。这两个分量的分数均方根振幅随能量的演化存在差异。我们进一步通过同时建模PDS以及交叉谱的实部和虚部来研究相位滞后特性，发现两个分量呈现出截然不同的相位滞后行为。总体而言，这些结果表明，QPO特征的表观能量依赖演化可能是存在多个变率分量的结果。
英文摘要
We present complex energy-resolved properties of quasi-periodic oscillations (QPOs) in the black hole X-ray binary GRS 1915+105 using an observation from the LAXPC instrument onboard AstroSat. Power density spectra (PDSs) are constructed in multiple energy bands and modeled with multi-Lorentzian components to investigate the energy dependence of QPO properties. The QPO frequency shows a modest increase with energy. Dynamic PDS analysis does not reveal clear evidence for time-dependent evolution of the QPO frequency, suggesting that the observed frequency shift is not primarily driven by temporal variability. We perform simultaneous fitting of energy-resolved PDSs and find that a model in which the QPO feature is described by two Lorentzian components provides a better fit. The two components exhibit different evolution in fractional root mean square amplitude as a function of energy. We further examine the phase-lag properties by simultaneously modeling the PDS and the real and imaginary parts of the cross-spectrum and find distinct phase-lag behavior for the two components. Overall, these results indicate that the apparent energy-dependent evolution of the QPO feature may be a result of the presence of more than one variability component.
