Collaborative Research: Hydrodynamic Simulations of the Local Group

本星系群（包括银河系、仙女座星系和它们的卫星星系）包含了宇宙中研究得最好的星系。这些天体可以作为我们理解星系形成和暗物质性质的罗塞塔石碑，暗物质占宇宙质量的80%以上。 黑暗母线仍然是神秘的，尚未通过直接方法发现。这两位研究人员将开发高度先进的超级计算机模拟本星系团成员的引力，从早期宇宙开始，并将模拟运行到今天。这些模拟将与最先进的观测结果进行比较，以进一步了解暗物质的性质以及星系如何形成。研究人员将与研究生密切合作，帮助培养他们成为具有宝贵计算技能的独立研究人员。研究人员还将参与与该提案相关的一系列更广泛的影响和推广工作。 其中一个将帮助指导和监督一个暑期项目，为高中生提供实践研究经验，并培养50%的女性和30%的少数民族学生对STEM领域的兴趣。 另一位研究员将致力于为代表性不足的学生提供资源，技能和联系，使他们能够追求并完成物理学和天文学的研究生学位。 此外，研究人员将通过一个基于网络的界面向公众提供他们的模拟星系目录和模拟观测，该界面已经在研究人员过去的项目中投入使用。该研究将包括总共七个高分辨率的局部星系群模拟，提供出色的统计数据。拟议工作的新方面将包括：（1）使用依赖于无网格流体动力学解算器的新代码来实现恒星形成和反馈物理学的复杂实现，以及（2）第一次研究具有足够高的分辨率，足够真实的物理模块和足够大的模拟体积来捕获矮卫星的形成，孤立的矮星，和银河系/仙女座类似物在同一模拟。研究人员将把模拟星系的星星形成历史、气体含量、形态、运动学和金属丰度与观测结果进行比较。一个关键的目标将是辨别宇宙再电离是否在矮星系的可观测性质中留下特征标记。

The Local Group of Galaxies (including the Milky Way, Andromeda, and their satellite galaxies) contains the best-studied galaxies in the Universe. These objects can act as a Rosetta Stone for our understanding of galaxy formation and the nature of Dark Matter, a substance that makes up more than 80% of the mass in the Universe. Dark Mater remains mysterious and is yet undetected through direct methods. The two investigators will develop highly advanced supercomputer simulations of the gravitational pull of members of the Local Group, beginning from the very early Universe and running the simulation to the present day. These simulations will be compared to state-of-the-art observations to further our understanding of the nature of Dark Matter and how galaxies form. The investigators will work closely with graduate students, helping to train them to be independent researchers with valuable computational skills.The investigators will also engage in an array of broader impact and outreach efforts associated with the proposal. One will help instruct and supervise a summer program that provides hands-on research experiences for high school students and fosters an interest in STEM fields to a student group of 50% women and 30% under-represented minorities. The other investigator will work to provide underrepresented students with resources, skills, and connections that will allow them to pursue and complete graduate degrees in Physics and Astronomy. Additionally, the investigators will provide their simulated galaxy catalogs and mock observations to the public via a web-based interface that is already operational for the investigators' past projects.The research will consist of a total of seven high-resolution simulations of Local-Group like volumes, providing excellent statistics. The novel aspects of the proposed work will include: (1) sophisticated implementations of star-formation and feedback physics using a new code that relies on meshless hydrodynamic solvers, and (2) the first study of a simulated Local Group that has high enough resolution, realistic enough physics modules, and a large enough simulated volume to capture the formation of dwarf satellites, isolated dwarfs, and Milky Way/Andromeda analogs in the same simulation. The investigators will compare the star formation histories, gas content, morphologies, kinematics, and metallicities of the simulated galaxies to observations. A key goal will be to discern whether cosmic reionization imprints characteristic signatures in observable properties of dwarf galaxies.