The 6.7 keV Line Emission from the Stellar Flare of Algol

We present spectral analysis of Algol stellar flare data. The 2-day observation of Algol in our Galaxy was done by Suzaku Satellite. Algol binary system consists of two component stars that eclipse one another periodically. The stellar magnetic field activities and Roche Lobe overflow/mass transfer mechanisms during rapid rotation of the component stars generate an X-ray emission. The variation in brightness of the stellar flare from epoch to epoch provides useful information of stellar properties of the component stars. The atomic physics of the Kα line emission process in the vicinities of chromospherically active and X-ray flare stars, and binaries is well understood. The photo ionization/collisional excitation in the Algol’s corona produces 6.7 keV line emission. The accumulated spectra in X-ray Imaging Spectrometer (XIS) sensors fitted combined with bremsstrahlung model and Gaussian line show a strong fixed X-ray energy of 6.7 keV.

M型星AT Mic的X射线耀发统计研究

恒星耀发是剧烈的恒星活动过程,对恒星周围行星的大气构成和生命演化有重大影响。恒星耀发的辐射主要分布在光学和X射线波段,其中耀发时X射线波段流量可以增大数十至数百倍。M型耀星是最有可能存在类地行星的宿主恒星,因此,研究M型耀星的X射线耀发分布对寻找宜居的类地行星具有重要意义,并且也可以为即将发射的爱因斯坦探针卫星(Einstein Probe,EP)对恒星耀发的探测数目估计提供参考。利用X射线全天成像监视器(Monitor of All-sky X-ray Image,MAXI)的巡天监测数据研究了M型耀星AT Mic的X射线耀发的统计性质。从X射线全天成像监视器11年的巡天数据中,通过分析图像、光变曲线和能谱数据的信息,发现X射线全天成像监视器在11年间共探测到10次信噪比大于3的耀发,获得了耀发光度的统计分布。在此基础上对恒星耀发的频率进行了估计,AT Mic每年产生耀发光度LX>1030 erg·s-1的次数约为83次,爱因斯坦探针卫星每年可以观测到AT Mic的耀发幅度达到两倍以上的次数约为8次。