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

亚利桑那大学的詹姆斯·利伯特博士将与德克萨斯大学的特德·冯·希佩尔(AST 0307315)和一组同事合作，解决银盘、厚盘和光晕年龄的基本问题。他们计划将银河系组件的年龄放在相同的相对年龄刻度上，使其在1 Gyr以内，并得出盘的绝对年龄在1到2 Gyr范围内。他们的项目还将改善对白矮星演化和光度功能的理解。在亚利桑那大学和德克萨斯大学的天文台进行的新观测，以及斯隆数字天空调查的使用，将产生2400多颗新的白矮星，这是一个没有运动学选择偏差的样本。USNO望远镜的精确天体测量将允许确定最重要的(最古老的)白矮星的子集的亲代种群。这些观测的结果将是一组白矮星的参数，这些参数足够精确地指导理论工作，并测量最重要的白矮星的子集的年龄。为了确保这项研究的广泛影响，该团队将在中学水平上编制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研讨会。这些材料还将由合作伙伴在网上传播。这些研讨会是国际和平研究所与麦克唐纳天文台、国家光学天文台和国家太阳天文台的教育推广人员合作举办的。*

AST 0307321PI: James LiebertINSTITUTION: University of ArizonaDr James Liebert of the University of Arizona will collaborate with Ted von Hippel of the University of Texas (AST 0307315) 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.***