Accretion onto the Companion of η Carinae during the Spectroscopic Event. II. X-Ray Emission Cycle
Accretion onto the Companion of η Carinae during the Spectroscopic Event. II. X-Ray Emission Cycle
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X 射线发射周期 II 期间对 η Carinae 伴星的吸积。
DOI：
10.1086/503317
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
E. Behar
中科院分区：
文献类型：
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作者：
Muhammad Akashi;N. Soker;E. Behar
本文计算了双星系统η Car在整个5.54年轨道周期内的X射线光度和光变曲线。通过使用一种新的方法，我们发现，在以前的工作中建议，碰撞的风吹的两颗恒星可以解释的X射线发射和时间行为。大部分2-10 keV波段的X射线辐射来自于受冲击的次级恒星风。观测到的X射线亮度在极小值之前的上升是由于密度的增加和随后的快速二次风辐射冷却时间的减少。吸收，特别是来自主风的软X射线，随着系统接近近星点而增加，并且冲击在主风内部深处产生。然而，吸收不能解释剧烈的X射线最小值。70天的最小值被认为是由两个风的碰撞区域坍塌到二级星星上造成的。这个过程被认为是关闭了次级风，从而关闭了主X射线源。我们表明，这一假设提供了一个唯象的X射线行为的描述周围的最小值。
We calculate the X-ray luminosity and light curve for the stellar binary system η Car for the entire orbital period of 5.54 yr. By using a new approach we find, as suggested in previous works, that the collision of the winds blown by the two stars can explain the X-ray emission and temporal behavior. Most X-ray emission in the 2-10 keV band results from the shocked secondary stellar wind. The observed rise in X-ray luminosity just before minimum is due to the increase in density and subsequent decrease in radiative cooling time of the shocked fast secondary wind. Absorption, particularly of the soft X-rays from the primary wind, increases as the system approaches periastron and the shocks are produced deep inside the primary wind. However, absorption cannot account for the drastic X-ray minimum. The 70 day minimum is assumed to result from the collapse of the collision region of the two winds onto the secondary star. This process is assumed to shut down the secondary wind, and hence the main X-ray source. We show that this assumption provides a phenomenological description of the X-ray behavior around the minimum.