论文标题
揭开深层嵌入式狼射线星WR 121A的本质
Unraveling the nature of a deeply embedded Wolf-Rayet star WR 121a
论文作者
论文摘要
一项X射线研究对Chandra和XMM-Newton的长期（超过12年）的档案观察进行了长期（超过12年）的档案观测，对深层嵌入式狼射线星WR 121A进行了研究。在WR 121A的X射线光曲线中，第一次检测到了4.1天的周期性变化。如J波段其他先前观察结果所示，在合并和暴露校正的WR 121a的Chandra X射线图像中没有看到任何伴侣。 WR 121a的X射线光谱已通过温度为0.98 +/- 0.34 keV的热等离子体发射模型，分别为凉爽和热的成分和非 - 极性丰度。本研究表明，WR121A是X射线明亮的巨大二进制文件之一，X射线光度为〜10^34 ERG/S，可以通过其组件之间的主动风碰撞来解释。在WR 121a的通量变化中，相锁定的调制量已在0.3-10.0 keV能量带中的最小值增加到最大值。这些变化可能是由二进制轨道中的次级恒星对风碰撞区域的日食引起的。 WR 121a的两个组件的风似乎是辐射的。辐射抑制作用以及辐射制动是在此短期大规模二进制系统中严重影响风碰撞的最有可能的过程。
An X-ray study of a deeply embedded Wolf-Rayet star WR 121a has been carried out using long-term (spanning over ~12 years) archival observations from Chandra and XMM-Newton. For the first time, a periodic variation with a period of 4.1 days has been detected in the X-ray light curve of WR 121a. No companion is seen in a merged and exposure corrected Chandra X-ray image of WR 121a as shown in the other previous observations in J-band. The X-ray spectrum of WR 121a has been well-explained by a thermal plasma emission model with temperatures of 0.98+/-0.34 keV and 3.55+/-0.69 keV for the cool and hot components, respectively and non-solar abundances. The present study indicates that WR121a is one of the X-ray bright massive binaries with an X-ray luminosity of ~10^34 erg/s, which can be explained by an active wind collision between its components. The phase-locked modulations have been seen in the flux variation of WR 121a where the flux is increased by a factor of ~1.6 from minimum to maximum in 0.3-10.0 keV energy band. These variations could be caused by an eclipse of the wind collision region by the secondary star in a binary orbit. The winds of both components of WR 121a appear to be radiative. Radiative inhibition as well as radiative braking are the most likely processes those are affecting the wind collision severely in this short period massive binary system.
