论文标题
Cygnus X-3的高分辨率Fe K频谱
The High resolution Fe K Spectrum of Cygnus X-3
论文作者
论文摘要
我们分析了高质量X射线二进制Cygnus X-3的Fe K光谱的特征。使用Chandra高能传输光谱仪以第三个衍射顺序获得光谱。三阶的能量分辨率增加使我们能够完全解析Fe XXVHEα复合物和Fe XXVILYα线。发射线频谱显示了光电离平衡的预期特征，这是在伴侣恒星的致密恒星风中激发的。除了吸收较低的电离状态下，我们还检测到内壳转变的离散发射。在Fe xxv n = 1-2所占据的光谱范围内观察到的发射线强度比禁止和结合线，这表明从Li和Be-Be-be-be-be-be-niner-hell发射中产生了很大的贡献。 Fe XXV禁止和兼容线在最接近紧凑型物体的电离区中出现，并且由于它们不受辐射转移效应的影响，因此我们可以原理使用它们来限制紧凑型物体的径向速度振幅。 We infer that the results indicate a compact object mass of the order of the mass of the Wolf-Rayet companion star, but we note that the presence of resonantly scattered radiation from Li-like ions may complicate the interpretation of the He-like emission spectrum, and specifically of the radial velocity curve of the Fe XXV forbidden line.
We analyze features of the Fe K spectrum of the high-mass X-ray binary Cygnus X-3. The spectrum was obtained with the Chandra High Energy Transmission Grating Spectrometer in the third diffraction order. The increased energy resolution of the third order enables us to fully resolve the Fe XXV Heα complex and the Fe XXVI Lyα lines. The emission-line spectrum shows the expected features of photoionization equilibrium, excited in the dense stellar wind of the companion star. We detect discrete emission from inner-shell transitions, in addition to absorption likely due to multiple unresolved transitions in lower ionization states. The emission-line intensity ratios observed in the range of the spectrum occupied by the Fe XXV n = 1-2 forbidden and intercombination lines suggest that there is a substantial contribution from resonantly scattered inner-shell emission from the Li- and Be-like ionization states. The Fe XXV forbidden and intercombination lines arise in the ionization zone closest to the compact object, and since they are not subject to radiative-transfer effects, we can use them in principle to constrain the radial velocity amplitude of the compact object. We infer that the results indicate a compact object mass of the order of the mass of the Wolf-Rayet companion star, but we note that the presence of resonantly scattered radiation from Li-like ions may complicate the interpretation of the He-like emission spectrum, and specifically of the radial velocity curve of the Fe XXV forbidden line.
