摘要
一个在ＰＳＰＣ 定位精度内与Ｍ８１ 球状星团Ｇ３５ 的光学位置相重合的Ｘ 射线源从４ 个曝光时间大于１１ ，０００ 秒的ＲＯＳＡＴＰＳＰＣ 定点观测中探测到，在改正了ＰＳＰＣ 指向中心的系统偏差后，它与Ｇ３５ 的光学位置相差～１０″．７ ，大大低于～３０″的ＰＳＰＣ 空间分辨率。对这个Ｘ射线源所作的ＲＯＳＡＴ 观测分析表明，它的ＰＳＰＣ 形态和Ｘ 射线辐射性质符合Ｍ８１ 球状星团亮源应有的特征。
Using four pointed observations of ROSAT PSPC with exposure time of >11,000 seconds, a X ray source has been found in a position consistent with the optical position of M81 globular cluster G35 within the position accuracy provide by PSPC. After correcting the systematic shift of the PSPC pointing center, the difference between the X ray position and G35 optical position is ～10″.7, well below the PSPC resolution of ～30″. The ROSAT observational analysis of the X ray source suggests that its PSPC morphology and X ray emission were consistent with the behaviour of the bright X ray sources of globular clusters.
