Observation of the Cygnus OB2 Association with Suzaku and Long-Term Light Curves
Observation of the Cygnus OB2 Association with Suzaku and Long-Term Light Curves
复制标题
天鹅座 OB2 与朱雀和长期光曲线关联的观测
DOI：
10.1093/pasj/63.sp3.s717
复制
发表时间：
2011
影响因子：
2.3
通讯作者：
H. Murakami
中科院分区：
文献类型：
--
作者：
M. Yoshida;S. Kitamoto;H. Murakami
我们获得了天鹅座 OB2 星团中四颗最亮的早期型恒星（天鹅座 OB2 5 号、8a 号、9 号和 12 号）的朱雀 41-ks 观测结果。其中两颗恒星（9 号和 12 号）的光谱可以通过两温度薄热碰撞电离平衡模型拟合，而 5 号和 8a 号的光谱则需要三温度模型。 8a 号恒星显示出高于 3 keV 和低于 1.5 keV 的时间变化。软X射线变化的时间尺度为8·10s，3keV以上的变化时间尺度为2·10s。我们发现超过 3 keV 的变化可以通过三温度模型中最热等离子体的温度变化来解释。该结果限制了三温度模型中最热部件的尺寸和密度。我们还制作了这四颗恒星 30 多年来的长期光变曲线。我们证实了8号a的强度存在轨道调制，并在9号的光变曲线中发现了可能的2.35年的轨道调制。
We obtained a Suzaku 41-ks observation of the four brightest early type stars in the Cygnus OB2 association (Cyg OB2 Nos. 5, 8a, 9, and 12). The spectra of two of the stars, Nos. 9 and 12, could be fitted by a two-temperature thin-thermal collisional-ionization equilibrium model, while those of Nos. 5 and 8a required a three-temperature model. Star No. 8a showed a time variation both above 3 keV and below 1.5 keV. The time scale of the variation of the soft X-rays is 8 10 s, while that above 3 keV is 2 10 s. We found that the variation above 3 keV can be explained by temperature changes in the hottest plasma of the three-temperature model. This result restricts the size and density of the hottest component of the three-temperature model. We also produced long-term light curves of the four stars for over 30 yr. We confirmed the orbital modulation in the intensity of No. 8a, and discovered a possible orbital modulation of 2.35 yr in the light curve of No. 9.
影响因子：
2.3
作者：
M. Kokubun;K. Makishima;T. Takahashi;T. Murakami;M. Tashiro;Y. Fukazawa;T. Kamae;G. Madejski
通讯作者：
M. Kokubun;K. Makishima;T. Takahashi;T. Murakami;M. Tashiro;Y. Fukazawa;T. Kamae;G. Madejski