A large, homogeneous open cluster white dwarf sample

0602288威廉姆斯，库尔蒂斯博士。威廉姆斯被授予美国国家科学基金会天文学和天体物理学博士后奖学金，在德克萨斯大学奥斯汀分校开展一项研究和教育计划。Williams博士将开发和分析一个开放星团白矮星的大样本，以满足下列研究目标：(1)汇编100个开放星团白矮星的样本，这些白矮星的前体质量大于1M太阳；(2)利用选定的白矮星亚样本，确定精确的初始-最终质量关系；(3)确定核心塌缩超新星前体的质量下限；(4)确定DB-DA(富氦大气和氢气大气)白矮星的比率；以及(5)确定开放星团中观测到的白矮星亏损的原因。这些目标将通过获得V22开放星系场中恒星的精确自行，并利用大型望远镜的后续光谱来识别和分类白矮星，并确定选定的亚样本的精确质量和冷却时间来实现。威廉姆斯还将参加一个现有的针对美国西南部地区科学教师的继续教育研讨会，重点是来自农村地区的教师，那里的学生主要来自代表人数不足的群体和下层家庭。威廉姆斯博士还将开设一个旨在向公众解释天文学新闻和研究的博客。

AST-0602288Williams, KurtisDr. Williams is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at the University of Texas-Austin. Dr. Williams will develop and analyze a large sample of open cluster white dwarfs in order to meet the following research goals: (1) to compile a sample of 100 open cluster white dwarfs with progenitor masses greater than 1Msolar, (2) to determine a precise initial-final mass relation using a selected sub-sample of white dwarfs, (3) to determine the lower-mass limit of core-collapse supernova progenitors, (4) to determine the ratio of DB-to-DA (helium-rich-atmosphere to hydrogen-atmosphere) white dwarfs, and (5) to determine the cause of the observed white dwarf deficit in open clusters. These goals will be met through the obtaining of accurate proper motions of stars in open cluster fields to V22, with follow-up spectroscopy on large telescopes to identify and classify the white dwarfs and to determine precise masses and cooling times for the selected sub-sample.Dr. Williams will also participate in an existing continuing-education workshop for science teachers from across the southwestern U.S., with an emphasis on teachers from rural regions in which students are primarily from underrepresented groups and lower-class families. Dr. Williams will also maintain a weblog aimed at explaining astronomy news and research to the general public.