Collaborative Research: White Dwarfs and the Star Formation History of the Galaxy

AST 0307315 PI：Ted von Hippel机构：德克萨斯大学奥斯汀分校。德克萨斯大学的Ted von Hippel将与亚利桑那大学的James Liebert（AST-0307321）和一组同事合作，解决银河系盘，厚盘和晕的年龄的基本问题。 他们计划将银河系各组成部分的年龄放在相同的相对年龄尺度上，误差在1 Gyr以内，并推导出盘的绝对年龄在1到2 Gyr以内。 他们的项目还将导致对白色矮星演化和光度功能的理解的改进。 亚利桑那大学和德克萨斯大学天文台的新观测，以及斯隆数字巡天的使用，将产生超过2400个新的白色矮星，一个不受运动学选择影响的样本。 美国国家科学院望远镜的精确天体测量将允许确定最重要的（最古老的）白色矮星的母星。这些观测的结果将是一组白色矮星的参数，这些参数足够精确，可以指导理论工作，并测量最重要的白色矮星子集的年龄。 为了确保这项研究的广泛影响，该小组将在中学一级制作关于恒星演化和银河系年龄的教学材料。这些材料将用于在麦克唐纳天文台举行的教师专业发展讲习班。 这些材料也将由合作伙伴和在网上传播。这些讲习班是PI与麦克唐纳天文台、国家光学天文台和国家太阳天文台的教育推广工作人员之间的合作。

AST 0307315PI: Ted von HippelINSTITUTION: University of Texas, AustinDr. Ted von Hippel of the University of Texas will collaborate with James Liebert of the University of Arizona (AST-0307321) and a team of colleagues to address fundamental questions of the ages of the Galactic disk, thick disk, and halo. They plan to place the ages of the Galactic components on the same relative age scale to within 1 Gyr, and derive an absolute age of the disk to within 1 to 2 Gyr. Their project will also lead to improvements in understanding of the evolution and luminosity function of white dwarfs. New observations at the University of Arizona's and the University of Texas' observatories, as well as use of the Sloan Digital Sky Survey, will yield more than 2400 new white dwarfs, a sample unbiased by kinematical selection. Precise astrometry from the USNO telescopes will allow the determination of the parent populations for a subset of the most important (oldest) white dwarfs. The result of these observations will be a set of parameters for white dwarfs that is precise enough to guide the theoretical work and to measure ages for a subset of the most important white dwarfs. To ensure broad impact of this research, the team will produce instructional materials at the secondary school level on stellar evolution and the age of the Galaxy. The materials will be used at teacher professional development workshops to be held at McDonald Observatory. The materials will also be disseminated by the partners and on the web. The workshops are a collaboration between the PI and the education outreach staff at McDonald Observatory, the National Optical Astronomy Observatory, and the National Solar Observatory.***