Collaborative Research: The Virgo Cluster as a Testbed for the Study of Galaxy Formation and Evolution

星系和星系团是可见的，因为恒星和热气体发出的光。然而，这些结构中的恒星和气体的质量大大超过了暗物质的质量。暗物质无法直接观测，但暗物质的引力效应可以在恒星、气体和球状星团（GCs）等星团的分布和运动中观察到。来自太平洋大学和加州大学圣克鲁斯的一个研究小组将利用GC的光谱观测来探测附近室女座星系团的暗物质含量，目的是了解大质量星系团的组装历史。该团队将继续通过加州大学圣克鲁斯分校的科学实习计划（SIP）与高中生合作。此外，太平洋大学和加州大学圣克鲁斯的本科生也将参与与该项目有关的研究。最后，他们将参加传统的外展活动，如公开讲座和讲习班，特别强调接触西班牙裔和拉丁裔社区。这利用了大量的GC，它们相对高的表面亮度，以及它们扩展的径向分布。主要的科学目标包括：（一）确定矮早型和超扩散星系的暗物质含量;（二）测试由GCs合并形成星系核的动力学摩擦假设;以及（iii）通过分析GC群体中发现的聚类、子结构和不对称性来理解聚类环境的影响，该奖项反映了NSF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。

Galaxies and clusters of galaxies are visible because of the light emitted by stars and hot gas. However, the mass of stars and gas in these structures is greatly exceeded by the mass of dark matter. Dark matter cannot be observed directly, but the gravitational effects of dark matter can be observed in the distribution and motion of stars, gas, and stellar clusters such as globular clusters (GCs). A team from the University of the Pacific and the University of California Santa Cruz will use spectroscopic observations of GCs to probe the dark matter content of the nearby Virgo cluster of galaxies with the goal of understanding the assembly history of massive galaxy clusters. The team will continue working with high school students through the Science Internship Program (SIP) at UC Santa Cruz. In addition, they will involve undergraduates from both the University of the Pacific and the University of California Santa Cruz in research relating to this project. Finally, they will participate in traditional outreach events such as public talks and workshops, with special emphasis on reaching Hispanic and Latino communities.The project will use GCs to study the assembly of structures in the Virgo cluster. This takes advantage of the large numbers of GCs, their relatively high surface brightness, and their extended radial distribution. The main scientific goals include: (i) determining the dark matter content of dwarf early-type and ultra-diffuse galaxies; (ii) testing the dynamical friction scenario for the formation of galaxy nuclei from mergers of GCs; and (iii) understanding the effects of the cluster environment through analysis of clustering, substructures, and asymmetries found in the GC population, and the study of cluster-centric radial trends of the stellar populations of Virgo dwarf ellipticals.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.