标题： 4U~1636$-$536 的 I 型 X 射线爆发后磁盘修复的 QPO 特征 显示英文标题

标题： QPO signatures of disk restoration after type-I X-ray bursts from 4U~1636$-$536

摘要： I型热核爆发（TNBs）来自中子星低质量X射线双星（NSLMXBs），起源于中子星表面，由吸积物质的不稳定燃烧引发。另一方面，千赫兹准周期振荡（QPOs）被认为起源于旋进吸积盘的最内层区域。由于爆发的剧烈性质，预计I型TNBs将影响内吸积流，因此也会影响kHz QPOs。在这项工作中，我们系统地研究了在4U 1636$-$536上，使用{\it{AstroSat}}观测，在3至20 keV能段范围内，I型TNB发生前后的上部和下部kHz QPO的演化。功率密度谱的分析显示，在I型爆发开始前的200秒内存在kHz QPOs。然而，在爆发后100到200秒内没有检测到明显的同一特征。kHz QPOs在$\approx$200秒后重新出现。3至20 keV频段内的分数均方根变化减少了$\approx$5-6%，支持了在爆发后200秒的非存在kHz QPOs的观点。200秒的时间尺度与粘性时间尺度相吻合，表明内盘因I型TNB的强烈辐射而暂时受到干扰。随着内盘恢复，kHz QPOs重新建立。 显示英文摘要

摘要： Type-I thermonuclear bursts (TNBs) from neutron star low-mass X-ray binaries (NSLMXBs) originate on the neutron star's surface from the unstable burning of the accreted material. On the other hand, kHz quasi-periodic oscillations (QPOs) are thought to originate in the innermost regions of the in-spiraling accretion disk. Due to the violent nature of the bursts, it is anticipated that Type-I TNBs will impact the inner accretion flow, and, therefore, the kHz QPOs. In this work, we systematically study the evolution of the upper and the lower kHz QPOs immediately before and after a Type-I TNB on 4U 1636$-$536 using {\it{AstroSat}} observations in the 3--20 keV band. The analysis of the power-density-spectra show the presence of kHz QPOs within 200 seconds before the onset of the Type--I burst. However, we have not detected any prominent signature of the same within 100-200 second posterior to the burst. The kHz QPOs then re-emerges after $\approx$ 200 sec. The fractional rms variation in the 3--20 keV band drops by $\approx$ 5-6 \%, supporting the non-existence of kHz QPOs in the 200 sec post-Burst Zone. The time scale of 200 sec coincides with the viscous time scale, highlighting a scenario where the inner disk is temporarily disrupted by the intense radiation from the Type-I TNB. The kHz QPO then re-establishes as the inner disk is restored.