论文标题
使用双光谱探测GRS 1915+105中的无线电X射线相关性
Using the bispectrum to probe radio X-ray correlations in GRS 1915+105
论文作者
论文摘要
我们介绍了表现出准周期振荡（QPOS）的GRS 1915+105观测结果的双晶格分析结果。双晶型是一个高阶统计量，可用于探测傅立叶频率三联体相之间的关系。尽管显示出非常相似的功率谱，但观测值在其两种方面表现出不同的模式，表明QPO以不同的方式将QPO与噪声耦合。我们表明，两种形式表现出与QPO的频率，硬度比以及源的无线电特性相关。特别是，我们发现QPO与高频和低频宽带组件之间的相位耦合的性质在无线电安静，无线电高原和无线电陡峭条件之间有所不同。我们还研究了在2Hz以上的QPO频率观测值的相位滞后行为，该观察频率在2Hz以上显示出不同的双晶格模式，并发现它们之间的统计学上显着差异，表明基本的物理机制发生了变化。最后，我们提出了一种场景，从积聚光盘中的软光子对喷气电子的冷却可以解释观察到的双晶和无线电性能之间的相关性。
We present the results of bicoherence analysis on observations of GRS 1915+105 that exhibit quasi-periodic oscillations (QPOs). The bicoherence is a higher order statistic that can be used to probe the relation between the phases of a triplet of Fourier frequencies. Despite showing very similar power spectra, the observations exhibit different patterns in their bicoherence, indicating that the QPOs are phase coupled to the noise in different ways. We show that the bicoherence pattern exhibited correlates with the frequency of the QPO, the hardness ratio, as well as the radio properties of the source. In particular, we find that the nature of phase coupling between the QPO and the high and low frequency broadband components is different between radio quiet, radio plateau and radio steep conditions. We also investigate the phase lag behaviour of observations with QPO frequency above 2Hz that show different bicoherence patterns, and find statistically significant differences between them, indicating a change in the underlying physical mechanism. Finally, we present a scenario whereby the cooling of the jet electrons by soft photons from the accretion disc could explain the observed correlations between the bicoherence and radio properties.
