论文标题
X射线观察Roche-Lobe填充白色矮人加热细分系统ZTF J213056.71+442046.5
X-ray observation of the Roche-lobe filling white dwarf plus hot subdwarf system ZTF J213056.71+442046.5
论文作者
论文摘要
ZTF J213056.71+442046.5是一类新近发现的紧凑型二进制文件的原型，该二进制文件由白色矮人和一个填充其Roche-lobe的热分子组成。它的轨道周期仅为39分钟，是该类别中对象已知的最短。高轨道倾斜度（i = 86 dEG）以及积聚磁盘的存在的证据已从其光学光度和光谱数据的详细建模中推断出来。我们报告了2021年1月7日进行的XMM-NEWTON观察结果。ZTF J213056.71+442046.5由光学监视器清楚地检测到，该光学监视器在紫外线（200-400 nm）中的周期性变化，其周期性变化，其光曲线类似于较长的波长。尽管白矮人的积聚为10^{ - 9} m_sun/yr的阶段，但使用Epic仪器检测到X射线，在0.2-12 KEV亮度上，epic仪器的X射线量为〜10^{30} erg/s。我们讨论了该系统缺乏强大X射线发射的可能解释。
ZTF J213056.71+442046.5 is the prototype of a small class of recently discovered compact binaries composed of a white dwarf and a hot subdwarf that fills its Roche-lobe. Its orbital period of only 39 min is the shortest known for the objects in this class. Evidence for a high orbital inclination (i=86 deg) and for the presence of an accretion disk has been inferred from a detailed modeling of its optical photometric and spectroscopic data. We report the results of an XMM-Newton observation carried out on 2021 January 7. ZTF J213056.71+442046.5 was clearly detected by the Optical Monitor, which showed a periodic variability in the UV band (200-400 nm), with a light curve similar to that seen at longer wavelengths. Despite accretion on the white dwarf at an estimated rate of the order of 10^{-9} M_sun/yr, no X-rays were detected with the EPIC instrument, with a limit of ~10^{30} erg/s on the 0.2-12 keV luminosity. We discuss possible explanations for the lack of a strong X-ray emission from this system.
