Collaborative Research: An Archaeological Survey for Substructure in the Stellar Halos of the Nearest Massive Galaxies

合作研究：最近的大质量星系星晕下部结构的考古调查

• 批准号: 1821987
• 负责人: David Sand
• 金额: $ 17.05万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1821987&HistoricalAwards=false
• 关键词: Collaborative; Research; Archaeological; Survey; Substructure

Our Milky Way galaxy is surrounded by "dwarf" galaxies that orbit and occasionally collide with our galaxy. We are part of a "local group" of large galaxies, each with its own swarm of dwarf galaxies. One of the important unanswered questions in astronomy is how these galaxies formed and how they change in time. Our current understanding of structure in the universe suggests that a large galaxy like the Milky Way should actually host a larger number of dwarf satellites than we observe. To examine whether this is universal or merely a property of our local group, this program will conduct a detailed census of the regions surrounding two of our nearest galactic neighbors. They will survey two types of galaxy - spiral, like the Milky Way, and a large elliptical galaxy - and then measure the basic properties of these newly discovered systems. This involves a collaborative effort between three institutions and will use some of the largest and best ground-based telescopes. All three PIs are active in education and public outreach. PI Sand's institution, Texas Tech University, has a new astrophysics research group and undergraduate concentration. The science in this proposal will help establish TTU's astrophysics program and reach out to the larger Lubbock community. In particular, two undergraduate astrophysics students will spend summers in California doing research for the program, allowing them to interact with the larger astrophysics community. PI Guhathakurta is very actively involved with several programs that provide mentoring and research experiences for high-school students. The three PIs, along with a postdoctoral researcher and students, will address the observed lack of faint dwarf galaxies associated with the Milky Way and M31 (compared Lambda-CDM predictions for small-scale structure formation). Using the Magellan and Keck telescopes, they will conduct a panoramic imaging study to measure the stellar stream and dwarf galaxy content in NGC 253, a Milky Way-like spiral in a filamentary environment, and NGC 5128, a massive central elliptical galaxy. They will also use Keck+Diemos and newly-developed coaddition techniques to obtain spectra of tidal streams and dwarf galaxies. If successful, this would enable kinematic and metallicity studies for the first time outside the local group.

我们的银河系被环绕着的“矮”星系，轨道和偶尔碰撞我们的星系。 我们是一个由大型星系组成的“本星系群”的一部分，每个星系都有自己的矮星系群。 天文学中一个重要的未解问题是这些星系是如何形成的，以及它们如何随时间变化。 我们目前对宇宙结构的理解表明，像银河系这样的大星系实际上应该拥有比我们观察到的更多的矮卫星。 为了检验这是否是普遍的，或者仅仅是我们本星系的一个属性，这个计划将对我们最近的两个银河系邻居周围的区域进行详细的普查。 他们将调查两种类型的星系-螺旋星系，如银河系，和一个大的椭圆星系-然后测量这些新发现的系统的基本属性。这涉及三个机构之间的合作努力，并将使用一些最大和最好的地面望远镜。 这三个项目负责人都积极参与教育和公共宣传活动。PI桑德的机构，得克萨斯理工大学，有一个新的天体物理学研究小组和本科集中。 这项建议中的科学将有助于建立TTU的天体物理学计划，并接触到更大的拉伯克社区。 特别是，两名天体物理学本科生将在加州度过夏天，为该项目做研究，使他们能够与更大的天体物理学社区互动。PI Guhathakurta非常积极地参与了几个为高中生提供指导和研究经验的项目。 这三个PI，沿着一个博士后研究员和学生，将解决观测到的与银河系和M31相关的暗淡矮星系的缺乏（比较Lambda-CDM对小尺度结构形成的预测）。 他们将使用麦哲伦和凯克望远镜进行全景成像研究，以测量NGC 253（一个在银河系环境中的银河系样螺旋）和NGC 5128（一个巨大的中央椭圆星系）中的恒星流和矮星系内容。 他们还将使用Keck+Diemos和新开发的共同添加技术来获得潮汐流和矮星系的光谱。 如果成功的话，这将使运动学和金属丰度研究首次在当地集团之外。