Collaborative Research: A New Era of Mapping Dark Matter in Dwarf Spheroidal Galaxies

合作研究：绘制矮球状星系暗物质图谱的新时代

• 批准号: 0205790
• 负责人: Edward Olszewski
• 金额: --
• 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: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0205790&HistoricalAwards=false
• 关键词: Collaborative; Research; New; Era; Mapping

AST 0205790OlszewskiDwarf spheroidal galaxies (dSph) are likely to be the smallest systems in the Universe which contain both dark matter and luminous matter. The dark matter content and distribution in dSphgalaxies can be studied in detail if one can collect enough kinematic data to constrain models. Dr. Mario Mateo, at the University of Michigan, and Dr. Edward Olszewski, at the University of Arizona, will use three new technologies to make a factor of 10-30 advance in the number of stellar velocities measured per galaxy. The goal is no longer to weigh the dSph's, but to derive the distribution of mass, thus the distribution of the dark matter. While small steps have been taken towards that goal to date, with heroically collected samples of up to 200 stars, it is only withsubstantially larger samples that reasonable models will be distinguished from each other. Suchmapping of the mass within dSph galaxies is required to critically compare their dark-matter haloswith the many - sometimes contradictory - predictions of models of galaxy and large-scale structure formation in the Universe. These researchers will use a new telescope - the Magellan 6.5-meter telescope of Las Campanas Observatory in Chile - a new echelle spectrograph - the Magellan-Inamori-Kyocera Echelle (MIKE) spectrograph - and a new 256-fiber system to feed this spectrograph a large number of stars simultaneously. This instrumental combination will allow the collection of 750-1500 kinematic samples per galaxy. ***

AST 0205790Olszewski 矮椭球星系 (dSph) 可能是宇宙中同时包含暗物质和发光物质的最小系统。如果能够收集足够的运动学数据来约束模型，就可以详细研究 dSph 星系中的暗物质含量和分布。 密歇根大学的 Mario Mateo 博士和亚利桑那大学的 Edward Olszewski 博士将使用三项新技术，将每个星系测量到的恒星速度数量提高 10-30 倍。目标不再是衡量 dSph 的重量，而是导出质量分布，从而导出暗物质的分布。虽然迄今为止，我们已经朝着这一目标迈出了一小步，勇敢地收集了多达 200 颗恒星的样本，但只有在样本量大得多的情况下，合理的模型才能相互区分。需要对 dSph 星系内的质量进行这种绘制，以严格比较它们的暗物质晕与对星系和宇宙中大规模结构形成模型的许多（有时是矛盾的）预测。这些研究人员将使用一台新望远镜——智利拉斯坎帕纳斯天文台的麦哲伦 6.5 米望远镜——一台新的阶梯光栅摄谱仪——麦哲伦-稻森-京瓷阶梯光栅 (MIKE) 摄谱仪——以及一个新的 256 光纤系统来为该摄谱仪提供大量恒星同时出现。这种仪器组合将允许每个星系收集 750-1500 个运动学样本。 ***