论文标题
Nustar和Astrosat观察热核X射线爆发，在4U 1636 $ - $ 536中以短期时间为单位
NuSTAR and AstroSat observations of thermonuclear X-ray bursts with short-recurrence times in 4U 1636$-$536
论文作者
论文摘要
我们报告了对环礁源4U 1636 $ - $ 536的光谱分析的结果，在其硬光谱状态下与Nustar和Astrosat观察到了536美元。在三个207 KS总暴露的观察结果中，我们确定了31个热核X射线爆发，其中包括5个双打和一个三元组。在其中一个双线仪中可以看到复发时间短至3.8分钟。据我们所知，这是该来源已知的最短复发时间。在爆发期间，我们的时间平均光谱表明在少数情况下存在额外的PowerLaw或黑体组件，这可能是由于在爆发期间的温度变化或与理想的黑体行为的合理偏离所致，但是，由于统计数据有限，很难使用时间分辨的光谱探测到这一点。使用吸收的黑体模型，温度在1.7至2.2 KEV之间，时间分辨的爆发非常适合。在两个X射线突发中，在衰减阶段以3 $σ$置信度检测到581 Hz左右的爆发振荡。在582 Hz处看到了一个爆发振荡，这是该来源2001年超级爆炸期间观察到的频率。
We report results from the spectro-timing analysis of the atoll source 4U 1636$-$536 observed with NuSTAR and AstroSat during its hard spectral state. In three observations of 207 ks total exposure, we identify 31 thermonuclear X-ray bursts including five doublets and a triplet. Recurrence time as short as 3.8 minutes is seen in one of the doublets. To the best of our knowledge, this is the shortest recurrence time known for this source. Our time-averaged spectroscopy during the bursts indicate the presence of an additional powerlaw or a blackbody component in a few cases, perhaps due to varying temperatures during bursts or plausible deviation from ideal blackbody behavior, however, it is difficult to probe this using the time-resolved spectroscopy owing to limited statistics. Time-resolved bursts are well fit using an absorbed blackbody model with temperatures varying between 1.7 and 2.2 keV. Burst oscillations around 581 Hz are detected with 3$σ$ confidence during the decay phase in two of the X-ray bursts. One of the burst oscillations is seen at 582 Hz, a frequency observed during the 2001 superburst in this source.
