Luminous High-Redshift Stars and Dark Matter Substructure Using Galaxy Cluster Lenses

使用星系团透镜的发光高红移恒星和暗物质子结构

• 批准号: 2308051
• 负责人: Patrick Kelly
• 金额: $ 42.12万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2308051&HistoricalAwards=false
• 关键词: Luminous; Redshift; Stars; Dark; Matter

More than four fifths of the matter in the universe consists of a form of matter that does not interact with or produce light and is, therefore, dark. Despite decades of searches, the nature of the dark matter is not yet known. As light passes through or close to a galaxy cluster, its path is bent by both the dark and luminous matter, and cluster lenses can create multiple, magnified images of background galaxies. In this project, scientists the University of Minnesota will measure the lensing magnification of mirrored images of ionized gas clouds in these background galaxies to carry out a new test of leading theories of dark matter. A second component of the program will be to seek to identify individual stars that are highly magnified in imaging from the upcoming Large Survey of Space and Time (LSST). These magnified stars are visible across most of the observable universe and studying them will open a new window into the universe when it was much younger. Moreover, changes in these stars’ brightness should provide new evidence about the nature of dark matter. In collaboration with the University of Minnesota’s Bell Museum, the team will also develop a new live-facilitated program for its 120-seat planetarium about past and current questions surrounding the cosmic expansion. The planetarium show, which will be targeted towards middle-school students but able to engage adults, will become a part of the Bell Museum’s regular daily rotation, and reach tens of thousands of students and visitors. The research team will acquire ground-based spectroscopy of pairs of mirrored images of HII regions in magnified arcs. Differences between the brightnesses, and therefore magnifications, of these pairs of images must arise from dark-matter substructure, since the large sizes of HII regions imply that their fluxes are not affected by microlensing from stars in the foreground cluster. These measurements will be compared to predictions from both cold dark matter (CDM) and ultralight boson dark matter. The second goal of this project is to study stars at cosmological distances that are sufficiently magnified to be detected. The team will develop tools to identify these events in LSST data, and obtain follow-up spectroscopy and imaging to study the detailed properties of the luminous stars beyond the local universe. The stars’ light curves should contain rapid fluctuations if axion minihalos are present in the galaxy cluster.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.

宇宙中超过五分之四的物质是不与光相互作用或产生光的，因此是暗物质，尽管经过数十年的研究，当光穿过或接近时，暗物质的性质仍然未知。到星系团时，它的路径会被暗物质和发光物质弯曲，并且星系团透镜可以创建背景星系的多个放大图像。在这个项目中，明尼苏达大学的科学家将测量电离气体镜像图像的透镜放大率。云该计划的第二个组成部分将是寻找在即将到来的大型时空巡天（LSST）成像中被高度放大的单个恒星。这些放大的恒星在大部分可观测的宇宙中都是可见的，研究它们将为了解更年轻的宇宙打开一扇新的窗户。此外，这些恒星亮度的变化应该可以提供有关暗物质性质的新证据。明尼苏达大学贝尔分校博物馆中，该团队还将为其 120 个座位的天文馆开发一个新的现场辅助节目，讲述有关宇宙扩张的过去和当前的问题。该天文馆节目将面向中学生，但能够吸引成年人。作为贝尔博物馆日常轮换的一部分，研究小组将获取 HII 区域放大弧形镜像对的地面光谱。这些图像对的亮度和放大倍数必定来自暗物质子结构，因为 HII 区域的大尺寸意味着它们的通量不受前景星团中恒星的微透镜的影响。这些测量结果将与预测进行比较。该项目的第二个目标是研究宇宙学距离上的恒星，这些恒星被放大到足以被探测到。 LSST 数据，并获得后续光谱和成像，以研究当地宇宙之外的发光恒星的详细反射特性，如果星系团中存在轴子迷你晕，恒星的光变曲线应包含快速波动。该奖项是 NSF 的法定奖项。使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。