Investigations of Star Clusters

星团研究

• 批准号: 9218873
• 负责人: Kyle Cudworth
• 金额: $ 18.9万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-02-15 至 1999-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9218873&HistoricalAwards=false
• 关键词: Investigations; Star; Clusters

Investigations of Star Clusters. Star cluster research at Yerkes Observatory primarily involves astrometric (proper motions) and photometric studies of globular clusters, dwarf spheroidal galaxies, and a few open clusters. Proper motions are used to derive cluster membership, study the internal dynamics of the nearer clusters, and derive space velocities. High quality photometry is normally obtained along with the astrometry to produce very clean color-magnitude diagrams. In some globular clusters the proper motions are combined with radial velocities obtained by Dr. Cudworth and others to further constrain dynamical models and to derive distances with sufficient precision to provide a useful new calibration of the globular cluster distance scale independent of "standard candle" assumptions. Absolute proper motions and hence space velocities are being determined for globulars and some dwarf spheroidal galaxies. With an emphasis on space velocity derivations for very distant globulars and dwarf speroidals, Dr. Cudworth will be able to place better constrains on the mass of the Milky Way.

星团的研究。耶基斯天文台的星团研究主要包括天体测量（固有运动）和球状星团、矮球状星系和一些疏散星团的光度研究。利用固有运动来推导星系团的隶属度，研究邻近星系团的内部动力学，并推导空间速度。高质量的光度测量通常与天体测量一起获得，以产生非常干净的颜色星等图。在一些球状星团中，适当的运动与Cudworth博士和其他人获得的径向速度相结合，以进一步约束动力学模型，并以足够的精度推导出距离，从而提供一个有用的球状星团距离尺度的新校准，而不依赖于“标准蜡烛”假设。球状星团和一些矮球状星系的绝对固有运动和空间速度正在被确定。Cudworth博士将重点放在非常遥远的球状星团和矮球状星团的空间速度推导上，这样他就能更好地约束银河系的质量。