AI 中文总结
本研究通过光谱分析5个带快速波动的长热核X射线暴，发现其吸积盘因辐射驱动翘曲而形变，为探究吸积盘粘滞强度提供了观测依据。
AI 中文摘要
中子星表面产生的热核X射线暴会影响周围的吸积流，揭示影响吸积物理的潜在物理过程细节。在此背景下，我们对5个长X射线暴进行了光谱分析，这些X射线暴的光变曲线尾部表现出短暂的快速流量变化。在所有情况下，从波动前、波动期间和波动后提取的光谱都显示出相对论性电离反射的证据，而来自中子星的黑体辐射常被隐藏。当波动开始和停止时，反射区域的性质以及观测到的黑体辐射占比都会发生变化。我们将这些结果与5个光变曲线无波动的相似X射线暴样本进行比较，发现对照样本中4个暴的光谱最适合用简单的吸收黑体来描述。与无波动的暴相比，有波动的暴更长、能量更高，这与辐射驱动的翘曲影响了有波动暴的吸积盘的预测一致。这一结果还意味着这些吸积盘必须具有大的粘滞系数。对照样本中暴缺乏反射的原因可能是吸积率较低，因为这些盘的表面密度更小，会因暴的加热而膨胀并变得康普顿薄。对发生翘曲的X射线暴进行高通量、时间分辨的光谱分析，将有助于深入了解吸积盘粘滞的强度。
英文摘要
Thermonuclear X-ray bursts from the surfaces of neutron stars affect the surrounding accretion flow, revealing details of the underlying physical processes influencing accretion physics. In this context, we perform a spectral analysis of 5 long X-ray bursts that exhibit temporary rapid flux variations during the tails of their light curves. In all cases, spectra extracted from before, during and after the time of fluctuations show evidence for relativistic, ionized reflection with the blackbody from the neutron star often hidden from view. Both the properties of the reflecting region and the observed fraction of the blackbody vary as the fluctuations start and stop. These results are compared to a sample of 5 similar bursts without fluctuations in their light curves, and we find that spectra from 4 of the bursts in the control sample are best described by a simple absorbed blackbody. The bursts with fluctuations are longer and more energetic than those without fluctuations, in agreement with the prediction that radiatively-driven warps are impacting the accretion disks of the bursts with fluctuations. This result would also imply that these accretion disks must have large viscosity parameters. The lack of reflection in bursts from the control sample may result from lower accretion rates, as these disks would have smaller surface densities and would expand and become Compton-thin due to heating from the burst. High-throughput, time-resolved spectral analysis of X-ray bursts that undergo warping would give insight into the strength of accretion disk viscosity.
Comments17 pages plus Appendices, 15 figures, accepted by ApJ
