论文标题
与印度太空任务Astrosat的超X射线源holmberg ii X-1的同时X射线/紫外线观测
Simultaneous X-ray/UV observations of ultraluminous X-ray source Holmberg II X-1 with Indian space mission AstroSat
论文作者
论文摘要
我们介绍了8个同时紫外线的紫外线和X射线观测值的结果高度可变的超充血X射线源（ULX）Holmberg II X-1与Astrosat-Astrosat-Indian Multi-Dovavelength Space Satellite。在2016年底至2020年初的整个观察期内，Holmberg II X-1显示中等X射线光度为$ 8 \ times10^{39} $ erg/s，以及具有$γ\ Lessim 1.9 $的硬幂律频谱。由于对象在X射线中的变异性较低（因子1.5）和UV范围内的微不足道的可变性（上限$ \ of 25 $％），我们找不到这些范围中通量变化之间可靠的相关性。在每个特定的观察结果中，X射线变异性幅度更高，在$ \ sim10 $ ks甚至更短的时间尺度下，它相对于平均水平，达到2-3倍。我们以三个加热供体恒星，加热磁盘和加热风的模型来讨论我们的结果，并估计可变性的下限，这将允许拒绝其中的至少一部分。
We present the results of 8 epochs of simultaneous UV and X-ray observations of the highly variable ultraluminous X-ray source (ULX) Holmberg II X-1 with AstroSat -- Indian multiwavelength space satellite. During the entire observation period from late 2016 to early 2020, Holmberg II X-1 showed a moderate X-ray luminosity of $8\times10^{39}$ erg/s and a hard power-law spectrum with $Γ\lesssim 1.9$. Due to low variability of the object in X-rays (by a factor 1.5) and insignificant variability in the UV range (upper limit $\approx25$%) we could not find reliable correlation between flux changes in these ranges. Inside each particular observation, the X-ray variability amplitude is higher, it reaches a factor of 2-3 respect to the mean level at the time scales of $\sim10$ ks or even shorter. We discussed our results in terms of three models of a heated donor star, a heated disk and a heated wind, and estimated the lower limit to the variability which would allow to reject at least part of them.
