Chandra Detection of Doppler-shifted X-Ray Line Profiles from the Wind of ζ Puppis (O4 f)
Chandra Detection of Doppler-shifted X-Ray Line Profiles from the Wind of ζ Puppis (O4 f)
复制标题
钱德拉对 δ Puppis (O4 f) 风的多普勒位移 X 射线线轮廓的检测
DOI：
10.1086/320916
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
S. Ohtori
中科院分区：
文献类型：
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作者：
Michiaki Miura;S. Hagiwara;J. Nakamura;Yasushi Wako;Yuya Kawarai;S. Ohtori
本文报道用67 k S高能透射光栅对光学最亮的早期O型星星船尾座（O 4 f）的观测。在5-25 nm波长范围内的光谱中可以看到许多分辨的X射线线。钱德拉有足够的光谱分辨率来研究孤立的X射线线剖面的速度结构，并区分个别禁止，相互组合，共振（FIR）发射线在几个类氦离子，即使个别组件是强烈的多普勒展宽。与其他热恒星的X射线线剖面不同，Pupp的X射线线剖面呈现蓝移和偏斜，这为X射线源嵌入恒星风中提供了最清晰和最直接的证据。线越宽，重心向蓝移的趋势越大。24.78的N VII线是一个特殊的情况，显示出平顶轮廓。这表明它是在大部分风衰减之外的区域形成的。类氦离子线的灵敏度，以一个强的紫外线辐射场是用来推导的径向距离，在该线的S XV，Si XIII，Mg XI，Ne IX，和O VII的起源。的形成半径对应以及在每个线复合物的波长统一的连续光学深度，表明X射线线发射分布在整个恒星风。然而，S XV的排放线在风中形成的深度比标准风震模型的预期要深。
We report on a 67 ks High-Energy Transmission Grating observation of the optically brightest early O star ζ Puppis (O4 f). Many resolved X-ray lines are seen in the spectra over a wavelength range of 5-25 Å. Chandra has sufficient spectral resolution to study the velocity structure of isolated X-ray line profiles and to distinguish the individual forbidden, intercombination, and resonance (fir) emission lines in several He-like ions, even where the individual components are strongly Doppler-broadened. In contrast to X-ray line profiles in other hot stars, ζ Pup shows blueshifted and skewed line profiles, providing the clearest and most direct evidence that the X-ray sources are embedded in the stellar wind. The broader the line, the greater the blueward centroid shift tends to be. The N VII line at 24.78 Å is a special case, showing a flat-topped profile. This indicates that it is formed in regions beyond most of the wind attenuation. The sensitivity of the He-like ion fir lines to a strong UV radiation field is used to derive the radial distances at which lines of S XV, Si XIII, Mg XI, Ne IX, and O VII originate. The formation radii correspond well with a continuum optical depth of unity at the wavelength of each line complex, indicating that the X-ray line emission is distributed throughout the stellar wind. However, the S XV emission lines form deeper in the wind than expected from standard wind-shock models.