CAREER: Constraining the Nature and Distribution of Dark Matter in the Era of High-Precision Astrometry

如果星系只由恒星和气体等正常物质组成，那么观察到星系中的恒星的运动速度比预期的要快。多个研究领域的科学家一直在努力寻找这些高速度的原因。主要的观点是，存在着看不见的“暗物质”，它构成了星系内部的大部分物质。这种额外的物质极大地增加了对恒星的引力，使它们的运动速度比预期的要快。然而，天文学家和物理学家仍然不知道这种“暗物质”的确切性质。该计划将为我们的银河系建立新的模型，利用即将到来的调查来测量有多少“暗物质”，并测试其性质。这些模型将首次包含有关附近星系的新知识，比如麦哲伦星云。麦哲伦星云在南半球肉眼可见，并为我们的银河系增加了大量的“暗物质”。该计划将使整个社区都可以访问这些模型。这将允许公众和科学家自己对银河系中恒星的运动进行建模。这位研究人员创建了图森少数民族参与科学技术计划(TIMESTEP)。研究人员将通过在科学政策、外联和通信领域创建新的活动来支持学生的职业道路来扩展TIMESTEP计划。研究人员将在对暗物质粒子性质的不同假设下校准由大麦哲伦星云(LMC)诱导的暗物质尾迹的性质-冷暗物质(CDM)、模糊暗物质(FDM)和自作用暗物质(SIDM)。研究人员将使用一种基场展开技术(自洽场方法；SCF)来分析量化银河系+LMC的CDM暗物质分布。这项技术将在Auriga CDM宇宙学模拟中使用类似的银河系+大质量卫星系统的宇宙变焦进行验证。通过这些模拟和分析实现，将为当前/即将到来的光晕跟踪器(卫星、恒星流、球状星团和光晕恒星)的高精度运动学数据建立一个新的框架。特别是，这个项目将解决天体物理学中的基本问题：1)我们能否观察到作用中的动力学摩擦，这可能会告诉我们关于暗物质粒子的性质？2)暗物质在银河系中的分布是什么？这个奖项反映了美国国家科学基金会的法定任务，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Stars in galaxies are observed to be moving faster than expected if galaxies are only made up of normal material, like stars and gas. Scientists across multiple areas of research have been working to find the explanation for these high speeds. The leading idea is that there exists unseen, “dark matter” that makes up most of the material inside galaxies. This extra material greatly increases the gravitational pull on stars, making them move faster than expected. However, astronomers and physicists still do not know the exact nature of this “dark matter”. This program will build new models of our Galaxy that will use upcoming surveys to measure how much "dark matter" there is and test its properties. These models will be the first to include new knowledge about nearby galaxies, like the Magellanic Clouds. The Magellanic Clouds are visible to the naked eye in the Southern Hemisphere and are adding a lot of “dark matter” into our Milky Way. This program will make these models accessible to the entire community. This will allow the public and scientists to model the motions of stars in our Milky Way for themselves. The investigator created the Tucson Initiative for Minority Engagement in Science and Technology Program (TIMESTEP). The investigator will expand the TIMESTEP program by creating new activities in support of student career paths in the areas of Science Policy, Outreach, and Communication.The investigator will calibrate the properties of the dark matter wake induced by the Large Magellanic Cloud (LMC) under different assumptions of the dark matter particle’s nature—cold dark matter (CDM) vs. fuzzy dark matter (FDM) and self-interacting dark matter (SIDM). The investigator will use a basis field expansion technique (Self-Consistent Field Method; SCF) to analytically quantify the CDM dark matter distribution of the Milky Way + LMC. This technique will be validated using cosmological zooms of analogous Milky Way + massive satellite systems in the Auriga CDM cosmological simulations. With these simulations and analytic realizations, a new framework will be established for current/upcoming high-precision kinematic data of halo tracers (satellites, stellar streams, globular clusters, and halo stars). In particular, this project will tackle fundamental questions in astrophysics: 1) Can we observe dynamical friction in action and what might this tell us about the nature of the dark matter particle? 2) What is the distribution of dark matter in the Milky Way?This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.