标题： 白矮星质量确定的X射线光谱方法 外系统不确定性 显示英文标题

标题： X-ray spectroscopy method of white dwarf mass determination in intermediate polars. External systematic uncertainties

摘要： 中等极亮X射线源（IPs）中的白矮星（WDs）质量可以通过它们硬X射线能谱的形状来确定。 在这里，我们研究了这种X射线光谱方法中所有可能的系统误差的重要性，包括磁层有限半径和旋转、有限吸积柱高度以及相对于白矮星表面的吸积流倾角。 我们还研究了吸积加热的白矮星表面包层在增加白矮星半径的IPs中的重要性。 它们的存在改变了通常用于冷白矮星的质量-半径关系。 作为初步近似，我们使用厚度为$10^{-4}M_\odot$的氢包层模型，表面温度为 30 千开尔文。 我们提出了一个新的高亮度IPs硬X射线能谱模型网格，计算时采用了新的质量-半径关系。 该网格用于拟合Swift/BAT对47个IPs的光谱。 这个样本中的平均白矮星质量为 0.82 $M_\odot$，与通过光学方法得到的激变变星中的白矮星平均质量一致。 这意味着所计算的硬X射线能谱以及假设磁层半径接近于共转半径、吸积柱相对高度较小的假设基本上是正确的，因为大多数IPs具有高亮度。 但是，这个通用网格（以及之前的通用网格）无法为低亮度IPs提供正确结果，这些IPs的白矮星表面可能有相对较高的吸积柱。这样的IPs必须用单独的吸积柱模型进行研究。 显示英文摘要

摘要： The masses of white dwarfs (WDs) in intermediate polars (IPs) can be determined from the shape of their hard X-ray spectra. Here we study the importance of all possible systematic uncertainties in this X-ray spectroscopy method, including finite radii and rotation of magnetospheres, finite accretion column height and accretion-flow inclination relative to the WD surface. We also investigate the importance of accretion-heated envelopes on WD surfaces in IPs which are increasing WD radii. Their presence changes the commonly used mass-radius relation for cold white dwarfs. As a first approximation we use thick ($10^{-4}M_\odot$) hydrogen envelope models with a surface temperature of 30 kK. We present a new model grid of hard X-ray spectra of high-luminous IPs computed among other things with using a new mass-radius relation. This grid is used for fitting Swift/BAT spectra of 47 IPs. The average WD mass in this sample is 0.82 $M_\odot$ and coincides with the average WD mass in cataclysmic variables obtained by optical methods. This means that the calculated hard X-ray spectra and the assumptions made that the magnetospheric radii in IPs are close to the corotation radii, and the relative heights of the accretion columns are small are basically correct, because most IPs have high luminosities. But this universal grid (as well as previous universal grids) cannot give correct results for the low-luminous IPs with probably relatively tall accretion columns on the WD surfaces. Such IPs have to be investigated with individual accretion column models.