Collaborative Research: Dwarf Galaxies and the Nature of Dark Matter

合作研究：矮星系和暗物质的性质

• 批准号: 1313006
• 负责人: Edward Olszewski
• 金额: $ 9.86万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1313006&HistoricalAwards=false
• 关键词: Collaborative; Research; Dwarf; Galaxies; Nature

The nature of dark matter (DM) remains one of the leading unsolved problems in cosmology today, and absent any direct detection of the particles themselves, the structure of nearby dwarf galaxies remains one of the most promising avenues for learning about the temperature and self-interaction properties of DM because any deviations from the standard cold dark matter model should happen at low masses.Modern ideas regarding how galaxies form in the Universe involve some form of "hierarchical" process by which small systems progressively merged into ever larger systems like our Milky Way Galaxy. A key element of this paradigm regards how mergers proceed, which, in turn, relies on understanding the nature of the DM needed to drive the formation of galaxies within the observed lifetime of the Universe. Dwarf galaxies are the smallest, simplest entities with DM that also contain visible baryonic material in the form of stars and/or gas. As such, they---and particularly their dark halos---represent our best local analogs of the building blocks that initiated the hierarchical process. The broad goal of this project is to use empirical techniques---primarily kinematic observations of stars in nearby dwarf galaxies---to determine key properties of DM halos in these systems in a largely model-independent way.The specific aims of this project include (1) learning how DM is distributed within individual galaxies by measuring the central mass densities and core properties of DM halos, (2) exploring how the evolution of the baryonic matter may have altered the DM components in galaxies, (3) determining if DM halos are truly scale free, (4) mapping the extents of DM halos in dwarfs and understanding how their dark and visible components have merged into the greater halo of our Galaxy, and (5) laying the groundwork to reconstruct the properties of the primordial population of dwarfs that contributed to the assembly of our Galaxy. This project builds on decades of NSF-sponsored instrument building and research grants to aid our understanding of the nature of DM.The investigators will engage in educational activities with several K-12 teachers, give public talks, and participate in events such as "Ask an Astronomer." The project will also support graduate student training throughout the grant period.

暗物质（DM）的性质仍然是当今宇宙学的主要未解决问题之一，并且没有直接发现颗粒本身的任何直接检测，附近附近的矮人星系的结构仍然是学习温度和自我交互的最有前途的途径之一，以了解DM的任何偏差，因为与标准的寒冷暗物质模型有关某些形式的偏低范围都涉及众多的范围。小型系统逐渐合并到我们银河系等越来越大的系统中的过程。 该范式的关键要素是合并的进行方式，这反过来依赖于理解在观察到的宇宙寿命内推动星系形成所需的DM的性质。 矮星系是具有DM的最小，最简单的实体，它也包含恒星和/或气体形式的可见的重型材料。 因此，它们 - 尤其是他们的黑色光环 - - 代表了启动层次过程的构建基块的最佳本地类似物。 The broad goal of this project is to use empirical techniques---primarily kinematic observations of stars in nearby dwarf galaxies---to determine key properties of DM halos in these systems in a largely model-independent way.The specific aims of this project include (1) learning how DM is distributed within individual galaxies by measuring the central mass densities and core properties of DM halos, (2) exploring how the evolution of the重型物质可能会改变星系中的DM组件，（3）确定DM光环是否真正免费规模，（4）映射矮人中的DM光晕的范围，并了解它们的黑暗和可见的组成部分如何合并到我们银河系的更大的光环中，以及（5）将我们重新构成的构建de的构建de的构建de的属性构成d -d d d d ar的属性的构建，该属性是D -roffortial of Dromiald of def的属性，该属性的构建成本是d -d d ar of do的属性。 星系。 该项目建立在数十年来的NSF赞助的仪器建设和研究赠款的基础上，以帮助我们理解D. D.的性质。调查人员将与几位K-12教师一起从事教育活动，进行公开谈判，并参加诸如“询问天文学家”之类的活动。 该项目还将在整个赠款期间支持研究生培训。

项目成果

The Binary Fraction of Stars in Dwarf Galaxies: The Cases of Draco and Ursa Minor

矮星系中恒星的双星分数：天龙座和小熊座的例子

• DOI: 10.3847/1538-3881/aae3e4
• 发表时间: 2018
• 期刊: The Astronomical Journal
• 作者: Spencer, Meghin E.;Mateo, Mario;Olszewski, Edward W.;Walker, Matthew G.;McConnachie, Alan W.;Kirby, Evan N.
• 通讯作者: Kirby, Evan N.