MaxBCG Galaxy Clusters: Laboratories for Galaxy Evolution and Tools for Cosmology

McKay博士和他的团队将研究一组丰富的星系团，“MaxBCG目录”，他们已经从斯隆数字巡天（SDSS）的星系数据库中识别出来。 他们将重新处理SDSS的图像，以获得更好的星系亮度测量值。 他们将使用麦哲伦望远镜测量星系团内的星系运动，以估计每个星系团的质量。 测量弱引力透镜--星系团的引力扭曲了来自位于其后面的遥远星系的光的路径--将提供额外的质量估计。 这项研究的结果将把每个星系团的光学丰富度（其成员星系的数量和亮度）与其质量联系起来，这项工作的结果将被用来检验宇宙结构形成理论，这些理论可以预测星系团的质量如何在宇宙时间内积累。 星系团被广泛用于探测暗能量和广义相对论的宇宙学测试，因此这项研究将产生广泛的科学影响。 McKay博士和他的团队在指导本科研究人员方面有着出色的记录，并将让本科生和研究生参与这项工作。 他还将为即将入学的本科生讲授一个研究研讨会，他们将根据公共SDSS数据执行分析项目。

Dr McKay and his group will study a set of rich clusters of galaxies, the 'MaxBCG catalog', which they have identified from the galaxy database of the Sloan Digital Sky Survey (SDSS). They will reprocess the images from the SDSS to obtain better measures of the galaxy brightness. They will use the Magellan telescopes to measure galaxy motions within the cluster, to estimate the mass of each cluster. Measuring weak gravitational lensing -- the way in which the cluster's gravitational pull distorts the path of light from distant galaxies lying behind it -- will provide additional mass estimates. The results of this study will relate measures of the optical richness (the number and brightness of its member galaxies) of each cluster to its mass.The results of this work will be used to test theories of cosmic structure formation, which can predict how the mass that galaxy clusters should build up through cosmic time. Galaxy clusters are widely used in probing dark energy and in cosmological tests of General Relativity, so this research will have a broad scientific impact. Dr. McKay and his group have an excellent record in mentoring undergraduate researchers, and will involve both undergraduate and graduate students in this work. He will also teach a research seminar for incoming undergraduates in which they will perform analysis projects based on public SDSS data.