Testing SIDM with Realistic Galaxy Formation Simulations

使用真实的星系形成模拟测试 SIDM

• 批准号: 2013909
• 负责人: Ferah Munshi
• 金额: $ 36万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2022-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2013909&HistoricalAwards=false
• 关键词: Testing; SIDM; Realistic; Galaxy; Formation

This award funds the collaborative research activities of Professor Ferah Munshi at the University of Oklahoma.Most of the matter in our Universe resides in an unknown component, dark matter. We have learned this primarily by studying the gravitational interactions of galaxies. Therefore, astrophysical measurements are a compelling way of directly studying the properties of dark matter. The nature of dark matter remains one of the most important questions in physics. Gravitational evidence points to dark matter that is "cold", meaning that it moves slowly and therefore is probably a heavy particle. This is the Cold Dark Matter (CDM) model. However, decades of experimental effort to detect such a heavy particle have not yet yielded conclusive evidence. Also, the CDM model has faced challenges matching the observed properties of dwarf galaxies (galaxies smaller than our Milky Way). These problems have inspired alternative dark-matter models. One alternative model that may work well is Self-Interacting Dark Matter (SIDM). SIDM and CDM should yield different distributions of mass within dwarf galaxies, but this has not been modeled in detail. As part of her research, Professor Munshi will use state-of-the-art computer simulations to model dwarf galaxies with both the CDM model and the SIDM model. Data from these simulations will be evaluated against data from real galaxies in order to constrain the nature of dark matter. This research advances the scientific leadership of the United States in the understanding of dark matter. Moreover, this project will train future scientists, with the goal of diversifying the US technical workforce. An expanded and diversified scientific workforce helps to ensure that the US remains a leader in innovation and economic growth.More technically, the proposed research will result in a suite of high-resolution, state-of-the-art simulations of galaxy formation within the SIDM paradigm. SIDM preserves the large-scale success of CDM, while opening up the possibility of altering the small scales in testable ways using galaxy observations. The group will use the N-Body+SPH code ChaNGa to run a series of simulations. First will be "zoom" simulations of individual dwarf galaxies in order to test whether CDM of SIDM can reproduce the diverse range of rotation curves observed in real galaxies. These galaxies will be run in both CDM and SIDM. Second will be studies of "zoom" volumes that contain dozens of dwarfs from 1000 solar masses to 10^9 solar masses in order to directly compare the observed shapes of galaxies with those predicted in CDM vs. SIDM. Analytic models have shown that an SIDM model with an interaction cross-section of ~3 cm^2 g^-1 can reproduce the full range of galaxy rotation curves. This research will test this model across a range of galaxy simulations for the first time. The broader-impacts component of this project builds on the successful Pre-Major in Astronomy Program (Pre-MAP) at the University of Washington by establishing a Pre-Map-like first-year seminar at the University of Oklahoma through an existing "Introduction to Research" class, and will expand the program to include training more relevant to physics research in addition to astronomy. This program will not only develop a mentoring relationship between students and members of the Physics and Astronomy Department, but also utilize cohort-building activities to develop the students into a peer-support network for each other. Finally, this program will introduce the students to basic research tools and involve them in original research.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.

该奖项资助俄克拉何马大学Ferah Munshi教授的合作研究活动。我们宇宙中的大部分物质都存在于一种未知的成分——暗物质中。我们主要是通过研究星系间的引力相互作用了解到这一点的。因此，天体物理测量是直接研究暗物质性质的一种引人注目的方法。暗物质的本质仍然是物理学中最重要的问题之一。引力证据表明暗物质是“冷的”，这意味着它移动缓慢，因此可能是一种重粒子。这就是冷暗物质（CDM）模型。然而，几十年来检测这种重粒子的实验努力尚未产生确凿的证据。此外，CDM模型还面临着与观测到的矮星系（比我们的银河系小的星系）的特性相匹配的挑战。这些问题启发了其他暗物质模型。另一种可能有效的模型是自相互作用暗物质（SIDM）。SIDM和CDM应该在矮星系中产生不同的质量分布，但这还没有被详细地建模。作为她研究的一部分，Munshi教授将使用最先进的计算机模拟，用CDM模型和SIDM模型来模拟矮星系。来自这些模拟的数据将与来自真实星系的数据进行评估，以约束暗物质的本质。这项研究推动了美国在理解暗物质方面的科学领导地位。此外，该项目将培养未来的科学家，目标是使美国的技术劳动力多样化。扩大和多样化的科研队伍有助于确保美国在创新和经济增长方面保持领先地位。从技术上讲，拟议的研究将在SIDM范式下产生一套高分辨率，最先进的星系形成模拟。SIDM保留了CDM的大规模成功，同时开辟了利用星系观测以可测试的方式改变小尺度的可能性。该小组将使用N-Body+SPH代码ChaNGa来运行一系列模拟。首先将是对单个矮星系的“缩放”模拟，以测试SIDM的CDM是否能重现在真实星系中观测到的不同范围的旋转曲线。这些星系将在CDM和SIDM中运行。第二项将是“缩放”体积的研究，其中包含数十个矮星，从1000太阳质量到10太阳质量，以便直接将观测到的星系形状与CDM和SIDM预测的结果进行比较。解析模型表明，相互作用截面为~3 cm^2 g^-1的SIDM模型可以重现星系旋转曲线的全部范围。这项研究将首次在一系列星系模拟中测试这个模型。该项目的更广泛影响部分建立在华盛顿大学成功的天文学专业预科项目（Pre-MAP）的基础上，通过现有的“研究入门”课程在俄克拉何马大学建立了一个类似于Pre-MAP的一年级研讨会，并将扩展该项目，除天文学外，还将包括更多与物理研究相关的培训。该项目不仅将在学生和物理天文系成员之间建立师徒关系，还将利用群组建设活动将学生发展成相互支持的同伴网络。最后，本课程将向学生介绍基本的研究工具，并让他们参与原创性研究。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Quantifying Scatter in Galaxy Formation at the Lowest Masses

• DOI: 10.3847/1538-4357/ac0db6
• 发表时间: 2021-01
• 期刊: The Astrophysical Journal
• 作者: F. Munshi;A. Brooks;Elaad Applebaum;C. Christensen;T. Quinn;Serena K Sligh