标题： Swift J1858.6-0814的中子星X射线双星的快速光学和X射线时序研究 显示英文标题

标题： A rapid optical and X-ray timing study of the neutron star X-ray binary Swift J1858.6-0814

摘要： 我们介绍了对2018年和2019年光学（HiPERCAM和ULTRACAM）和X射线（NICER）观测数据的快速时间分析，对象是X射线暂现源Swift J1858.6-0814。 光学光曲线显示出相对缓慢且幅度较大的（约在g$_s$波段变化约1个星等）“蓝色”耀斑（即在较短波长下更强），时间尺度约为几分钟，以及快速但幅度较小（约在g$_s$波段变化约0.1个星等）的“红色”耀斑（即在较长波长下更强），时间尺度约为几秒。这些“蓝色”和“红色”耀斑分别与X射线再处理和光学薄同步辐射相一致，类似于在其他X射线双星系统中观察到的现象。 同时记录的光学与软、硬能段X射线光曲线显示了时间和能量相关的相关性。2019年3月4日的数据及部分6月数据展示了在正延迟时近乎对称的正交叉相关函数（CCF），这与简单的X射线盘再处理现象一致。软、硬能段的CCF相似，如果盘再处理在光学中占主导地位，并且一个成分（盘或同步辐射康普顿化）同时主导软、硬X射线，则可以重现这些CCF。 2019年6月的一部分数据展示了非常不同的CCF。如果光学同步辐射发射与高温流X射线发射相关，则可以在软能段再现负延迟时的正相关性。观测到的时间特性在定性上与混合内热吸积流模型一致，在该模型中，不同X射线和光学成分在爆发过程中以及较短时间内角色的变化决定了光学/X射线CCF的形状。 显示英文摘要

摘要： We present a rapid timing analysis of optical (HiPERCAM and ULTRACAM) and X-ray (NICER) observations of the X-ray transient Swift J1858.6-0814 during 2018 and 2019. The optical light curves show relatively slow, large amplitude (~1 mags in g$_s$) `blue' flares (i.e. stronger at shorter wavelengths) on time-scales of ~minutes as well as fast, small amplitude (~0.1 mag in g$_s$) `red' flares (i.e. stronger at longer wavelengths) on time-scales of ~seconds. The `blue' and `red' flares are consistent with X-ray reprocessing and optically thin synchrotron emission, respectively, similar to what is observed in other X-ray binaries. The simultaneous optical versus soft- and hard-band X-ray light curves show time- and energy dependent correlations. The 2019 March 4 and parts of the June data show a nearly symmetric positive cross correlations (CCFs) at positive lags consistent with simple X-ray disc reprocessing. The soft- and hard-band CCFs are similar and can be reproduced if disc reprocessing dominates in the optical and one component (disc or synchrotron Comptonization) dominates both the soft and hard X-rays. A part of the 2019 June data shows a very different CCFs. The observed positive correlation at negative lag in the soft-band can be reproduced if the optical synchrotron emission is correlated with the hot flow X-ray emission. The observed timing properties are in qualitative agreement with the hybrid inner hot accretion flow model, where the relative role of the different X-ray and optical components that vary during the course of the outburst, as well as on shorter time-scales, govern the shape of the optical/X-ray CCFs.