Collaborative Research: Age-Dating M31's Halo and Satellites - Testing the Lambda CDM Paradigm

合作研究：M31 光环和卫星的年龄测定 - 测试 Lambda CDM 范式

• 批准号: 1412648
• 负责人: Puragra Guha Thakurta
• 金额: $ 21.76万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1412648&HistoricalAwards=false
• 关键词: Collaborative; Research; Age; Dating; M31

Stellar halos, the roughly spherical clould of stars orbiting a spiral galaxy, provide unique insight into the formation and evolution of galaxies, and they may hold the key to understanding dark matter. From our position inside the Milky Way, we are unable to fully probe our own halo, because much of it is blocked from our view. M31 (the "Andromeda Galaxy") is near enough that we can measure properties of individual stars in its halo. This program will utilize existing data and obtain new observations of M31 in order to map the distribution star ages throughout its halo. This will permit them to determine the relative importance of several different mechanisms that can add stars to a galaxy halo. Ultimately, this will lead to a better understanding of the history of our own Milky Way galaxy. This program will create opportunities for both undergraduate and graduate student research at two institutions. The University of Virginia group works with amateur astronomers on galaxy evolution research projects and outreach programs to K-12 students in rural Virginia. The University of California - Santa Cruz team teaches underrepresented high school students through the COSMOS, MAGIC, and the Science Internship Programs. Both of the PIs teach large undergraduate courses, actively mentor students, give regular public lectures and speak in K-12 classrooms.The PIs will create the first age-distribution profile of the M31 stellar halo. This work leverages an enormous investment of telescope time over the past 10 years (the SPLASH project) and aims to add two significant new parameters: metallicity and age distributions. Three new observational methods will be applied, including a near infrared imaging survey across the M31 halo out to a distance of 180 kpc, optical time series of anomalous Cepheids in M31 satellite galaxies, and Keck/DEIMOS spectroscopy of M31 field and dSph stars. This work leverages an enormous investment of telescope time over the past 10 years (the SPLASH project) and aims to add two significant new parameters: metallicity and age distributions.

恒星晕是围绕螺旋星系运行的恒星的大致球形云，为星系的形成和演化提供了独特的见解，它们可能掌握着理解暗物质的关键。 从我们在银河系内的位置，我们无法完全探测我们自己的光环，因为它的大部分被阻挡在我们的视野之外。 M31（“仙女座星系”）足够近，我们可以测量其光环中单个恒星的属性。 该计划将利用现有的数据，并获得新的观测M31，以绘制整个光环的星星年龄分布图。 这将使他们能够确定几种不同机制的相对重要性，这些机制可以将恒星添加到星系晕中。 最终，这将有助于更好地了解我们银河系的历史。 该计划将为两个机构的本科生和研究生研究创造机会。弗吉尼亚大学的研究小组与业余天文学家合作，开展星系演化研究项目，并为弗吉尼亚州农村的K-12学生提供外展计划。加州大学-圣克鲁斯分校的团队通过宇宙、魔法和科学实习项目教授代表性不足的高中生。这两个项目研究员教授大型本科课程，积极指导学生，定期进行公开讲座，并在K-12教室发言。 这项工作利用了过去10年（SPLASH项目）对望远镜时间的巨大投资，旨在增加两个重要的新参数：金属丰度和年龄分布。 将采用三种新的观测方法，包括跨越M31晕到180 kpc距离的近红外成像调查，M31卫星星系中异常造父变星的光学时间序列，以及M31场和dSph星的Keck/DEIMOS光谱。 这项工作利用了过去10年（SPLASH项目）对望远镜时间的巨大投资，旨在增加两个重要的新参数：金属丰度和年龄分布。