US-West Germany Cooperative Research in Galactic Astronomy

该奖项为夏威夷大学天文研究所J. Patrick Henry教授到西德慕尼黑的马克斯·普朗克地外物理研究所进行休假访问提供了部分资助。他将参加德国领导的一项主要的星系团天文调查，使用卫星x射线设备（ROSAT），然后在夏威夷大学进行后续的光学研究。他的主要合作者将是研究所所长约阿希姆·特朗普博士和研究所的其他工作人员。ROSAT卫星定于1990年2月发射。整个天空的x射线成像调查预计将提供一个星系团的样本，其深度至少是光学选择的最深样本的两倍。ROSAT样本也将有完善的、可量化的选择标准，并将位于天空的一个连续区域。相对而言，美国天文学家很少能接触到调查数据；亨利教授是受邀参加调查阶段的极少数人之一。对宇宙中最大结构的研究可以告诉我们很多关于宇宙的历史和进化。星系通常被用来研究宇宙的结构。但是对星系的调查只完成了一定的规模。集群可以提供一个更大范围内的结构的大致概念。亨利教授将能够将位置群的数据传递给夏威夷的观测者。他和他的同事将重点研究星团x射线的演化和光学性质、大尺度结构以及经典的星等红移关系。ROSAT样本的深度和完整性将使这些研究比以前的工作产生重大改进。

This award provides partial support for a sabbatical visit to the Max Planck Institute for Extraterrestrial Physics, Munich, West Germany, for Professor J. Patrick Henry of the Institute for Astronomy, University of Hawaii. He will participate in a major German-led astronomical survey of clusters of galaxies using satellite based x-ray equipment (ROSAT), and then conduct followup optical studies at the University of Hawaii. His primary col- laborators will be the Institute Director, Dr. Joachim Trumper, and others on the Institute staff. The ROSAT satellite was to be launched in February, 1990. The x-ray imaging survey of the entire sky is expected to provide a sample of clusters of galaxies which will be at least twice as deep as the deepest optically selected samples. The ROSAT sample will also have well established, quantifiable selection criteria and will be in a contiguous region of the sky. U.S. astronomers will have relatively little access to survey data; Professor Henry is one of very few invited to participate in the survey phase. The study of the largest structures in the universe can tell us much about its history and evolution. Galaxies are classically used to investigate structure in the universe. But surveys of galaxies are only complete to a certain scale. Clusters can give a rough idea of structure on a much larger scale. Professor Henry will be able to relay data on position clusters to observers in Hawaii. He and his colleagues will emphasize studies of the evolution of cluster x-ray and optical properties, large scale structure, and the classical magnitude redshift relation. The depth and complete- ness of the ROSAT sample will enable these studies to produce significant improvements over previous work.