疏散星团M67中的红团簇巨星

发布时间：2018-01-16 23:32

本文关键词：疏散星团M67中的红团簇巨星　出处：《科学通报》2013年27期 　论文类型：期刊论文

【摘要】：红团簇巨星(red clump giant)被理论和观测证明是非常理想的标准烛光,可以用来精确测量天体的距离.利用2MASS星表(the two micron all sky survey)提供的近红外测光数据和UCAC4天体测量星表(the fourth U.S.naval observatory CCD astrograph catalog)提供的自行等数据分析了疏散星团M67,结合自行、颜色-星等图、高精度视向速度和金属丰度,能够辨认出7颗红团簇巨星是M67的成员星.这7颗红团簇巨星的视向速度、金属丰度以及KS星等值高度一致.基于这7颗红团簇巨星计算得到M67的绝对距离模数为9.48±0.04 mag(或表示成距离787±15 pc),比基于主序拟合法得到的距离明显偏小.分析显示有1颗红团簇巨星以18±10 km/s的速度相对于星团核心运动,原因可能是星团内部动力学演化导致能量均分,小质量恒星在碰撞中获得了更高的速度,从星团中逃逸.
[Abstract]:Red clump Giant) is proved to be an ideal standard candlelight by theory and observation. Can be used to accurately measure the distances of celestial bodies. Using the 2MASS catalog the two micron all sky survey. Near infrared photometry data and UCAC4 astrometry catalog. The fourth U.S.naval observatory CCD astrograph catalogs. The self-contained data are provided to analyze the open cluster M67. Combined with self-color-star map, high-precision apparent velocity and metal abundance, seven red cluster giant stars can be identified as M67 member stars. The apparent velocity of these 7 red cluster giants can be identified. The metal abundance and the equivalent height of KS star are consistent. The absolute distance modulus of M67 is 9.48 卤0.04 mag. based on the seven red cluster superstars. Or expressed as a distance of 787 卤15pc. The results show that there is a red cluster giant moving at a speed of 18 卤10 km/s relative to the core of the cluster. The reason may be that the internal dynamics of the cluster results in the equalization of energy, and the small mass stars get higher speed in the collision and escape from the cluster.
【作者单位】：常州大学信息科学与工程学院;
【基金】：国家自然科学基金(61063021) 常州大学校基金(ZMF1002121)资助
【分类号】：P154.11
【正文快照】： 疏散星团是靠万有引力束缚在一起的恒星系统,成员星数目一般为几十至几千颗,成员星之间有近似相同的年龄和化学成分,是研究恒星演化的重要实验室.相对场星而言,疏散星团的年龄、距离、金属丰度、红化等基本物理参数更容易被测定,是研究银盘结构与演化的理想示踪天体.M67(NGC 2

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