Collaborative Research: The SAGA Project: Searching for Dwarf Galaxies Around Milky Way Analogs

合作研究：SAGA 项目：寻找类似银河系周围的矮星系

• 批准号: 1517148
• 负责人: Marla Geha
• 金额: $ 32.29万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1517148&HistoricalAwards=false
• 关键词: Collaborative; Research; SAGA; Project; Searching

Our home galaxy, the Milky Way, is surrounded by dozens of smaller galaxies. These smaller galaxies are called dwarf galaxies. The properties of these dwarf galaxies provide clues to how galaxies form and can test the nature of dark matter. However, the number of Milky Way dwarf galaxies and their properties do not fully agree with well-established cosmological models. In order to understand this discrepancy, it is necessary to understand whether the Milky Way and its dwarf galaxy populations are typical of large spiral galaxies, or if the Milky Way is itself an unusual galaxy. The investigators will identify dwarf galaxies around 50 spiral galaxies similar to the Milky Way. These systems will be compared to predictions to determine whether the Milky Way's dwarf population is typical, and will provide new insight into the nature of dark matter and into the formation of our own Galaxy.The investigators work focuses on a key question of interest to the public: What is our place in the Universe? They will integrate results into their array of education and outreach activities, bringing the excitement of this rapidly-advancing field to a wider audience. They will create a wiki to collect and disseminate teaching resources, with the goal of lowering the bar to introducing new practices into the undergraduate astronomy classroom. While development of innovative and interactive undergraduate material has accelerated, a survey of university-level science faculty suggests that only a small fraction of this makes it into the classroom. A single well-designed wiki which gathers innovative undergraduate astrophysics teaching resources from the professors who use them is lacking and will significantly increase the use of such material.The investigators will constrain the distribution of dwarfs around Milky Way-mass galaxies (of which the Milky Way itself is a single example) by observationally identifying dwarf galaxy populations around at least 50 systems down to the luminosity of the Milky Way's Fornax dwarf galaxy (eight magnitudes fainter than the Milky Way). In parallel, they will construct a comprehensive theoretical framework based on cosmological dark matter simulations that fully utilizes the results of the observational program to provide insight into and place new constraints on models of galaxy formation and dark matter physics. Their goals are to: (1) provide the data and theoretical framework necessary to distinguish between the multiple proposed solutions to the "missing dwarf" and "too big to fail" problems and (2) provide an improved understanding of the Milky Way itself in a cosmological context.

我们的银河系被数十个较小的星系包围着。 这些较小的星系被称为矮星系。 这些矮星系的性质为星系如何形成提供了线索，并可以测试暗物质的性质。 然而，银河系矮星系的数量和它们的性质并不完全符合公认的宇宙学模型。 为了理解这种差异，有必要了解银河系及其矮星系群是否是典型的大型螺旋星系，或者银河系本身是否是一个不寻常的星系。 研究人员将在50个类似于银河系的螺旋星系周围识别矮星系。 这些系统将与预测进行比较，以确定银河系的矮人口是否是典型的，并将提供新的洞察暗物质的性质和我们自己的银河系的形成。调查人员的工作集中在一个公众感兴趣的关键问题：我们在宇宙中的位置是什么？他们将把研究结果融入到他们的一系列教育和推广活动中，把这个快速发展的领域的兴奋带给更广泛的受众。 他们将创建一个wiki来收集和传播教学资源，目的是降低将新实践引入本科天文学课堂的门槛。 虽然创新和互动的本科教材的开发已经加速，但对大学科学教师的调查表明，只有一小部分进入课堂。一个设计良好的wiki，从使用它们的教授那里收集创新的本科天体物理学教学资源，这是缺乏的，将大大增加此类材料的使用。（银河系本身就是一个例子）通过观测识别出至少50个系统周围的矮星系群，这些矮星系群的亮度低至银河系的天炉座矮星系（比银河系暗8个星等）。与此同时，他们将构建一个基于宇宙学暗物质模拟的全面理论框架，充分利用观测计划的结果，为星系形成和暗物质物理模型提供新的约束。 他们的目标是：（1）提供必要的数据和理论框架，以区分“失踪的矮”和“太大而不能倒”问题的多个建议解决方案;（2）在宇宙学背景下提供对银河系本身的更好理解。