Collaborative Research: Investigating the nature of dark matter with gravitational lensing

了解暗物质的本质是现代天体物理学中最紧迫的问题之一。这种神秘的物质构成了星系中的绝大多数物质，包括我们所在的银河系，但没有出现在任何拍摄的这些物体的图像中。此外，暗物质是与暗能量一起构成宇宙的两个主要组成部分之一。虽然暗物质的性质还不为人所知，但相对简单的暗物质模型已经在再现宇宙中星系的分布方面做了出色的工作。然而，当观察更小的尺度时，模型预测数千个小星系应该围绕银河系等星系运行，而对银河系的仔细观察发现的卫星星系不到50个。这个项目的主要目标是建立和分析足够大的稀有引力透镜系统样本，以区分不同的暗物质模型，从而进一步加深我们对宇宙最重要组成部分之一的了解。这个项目的兴奋之处将与公众分享，特别强调向年轻人介绍科学方法和尖端天体物理研究的技术。这将通过针对高中生的专门暑期项目、天文学和可持续能源的大学入门课程以及面向本科生的研究项目来实现。这个项目背后的基本问题是“暗物质的本质是什么？”我们现在知道，暗物质是宇宙质量能量的主要组成部分，仅次于暗能量，完全主导着星系和星系团的质量。然而，暗物质粒子的性质并没有很好地量化，因为在天体物理学和物理学中都在努力测量这些性质。这项拟议的研究利用了四个步骤来更好地理解暗物质：(1)通过将我们的引力成像和通量比异常技术应用于新样本来建立更好的统计数据，这将提供比目前数量显著增加的数据；(2)通过压下子结构质量函数的数量级，显著提高透镜方法分离冷和暖暗物质的能力；(3)开发技术来减少现在已知影响早期暗物质分析的系统误差；以及(4)对遥远星系中的子结构质量函数进行至少两次独立测量，并在替代暗物质模型的背景下分析结果。

Understanding the nature of dark matter is one of the most pressing issues in all of modern astrophysics. This mysterious substance makes up the vast majority of the material in galaxies, including our own Milky Way Galaxy, but does not appear in any images taken of these objects. Furthermore, dark matter is one of the two major components, along with dark energy, that make up the Universe. While the properties of dark matter are not well known, relatively simple models of it have done a remarkable job of reproducing the distribution of galaxies in the Universe. However, when looking on smaller scales, the models predict that thousands of small galaxies should orbit galaxies such as the Milky Way, while careful observations of the Milky Way have detected fewer than 50 satellite galaxies. The primary goal of this project is to build up and analyze a large enough sample of rare gravitational lens systems to distinguish between different models of dark matter and, thus, to further our knowledge about one of the most important components of the Universe. The excitement of this program will be shared with the public, with a special emphasis on introducing young people to the scientific method and to the techniques of cutting-edge astrophysics research. This will be accomplished through specialized summer programs for high-school students, introductory-level college classes in astronomy and sustainable energy, and research projects for undergraduates.The fundamental question underlying this project is "what is the nature of dark matter?". We now know that dark matter is a major component of the mass energy of the Universe, second only to dark energy, and completely dominates the mass of galaxies and galaxy clusters. However, the properties of the dark matter particle are not well quantified with efforts to measure these properties proceeding both in astrophysics and physics. The proposed research utilizes four steps to better understand dark matter: (1) building better statistics by applying our gravitational imaging and flux-ratio anomaly techniques to new samples that will provide a significant increase over our current numbers, (2) significantly improving the power of the lensing approach to disentangle cold and warm dark matter by pushing orders of magnitude down the mass function of substructures, (3) develop techniques to reduce systematic errors that are now known to have affected earlier dark matter analyses, and (4) do at least two independent measurements of the substructure mass function in distant galaxies and analyze the results in the context of alternative dark matter models.