Cosmological Strong Lensing: A Public Comparison of Theory with New Data Across Mass and Redshift

宇宙学强透镜：质量和红移理论与新数据的公开比较

• 批准号: 1616551
• 负责人: Michael Gladders
• 金额: $ 43.95万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-15 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1616551&HistoricalAwards=false
• 关键词: Cosmological; Strong; Lensing; Public; Comparison

This project will simulate elements of cosmology and compare those to observations, in particular using strong gravitational fields that act as lenses. The goal is to understand whether gravitational lenses can be used to understand the cosmological properties. What makes this project possible is the growing sample of strong gravitational lenses. These lenses are massive galaxies and clusters of galaxies that are so large they bend light coming from a more distant background object and passing near the lensing object. Studying these lenses and the lensed objects will allow the researchers to study the mass of the galaxies and clusters, the amount of dark matter, the distant object and space between the source, the lens, and us, and to determine fundamental properties of the universe. The main question to be answered by this project is: Do the properties of the most massive objects in the universe, which are acting as lenses, match those from astronomer's predictions from simulations of the unverse? If so, they can be used to understand more fundamental problems. If not, astronomers will have a better understanding of what needs to be done to their simulations to improve them. This project is possible now due to an increase in the number of observed lensing objects.In addition to the scientific portion of the project, the PI to increase diversity among American scientists by working with six Deaf undergraduate students from the National Technical Institute for the Deaf, as summer co-op students at the University of Chicago. By engaging them in scientific research early in their academic careers, this project aims to open career paths that they would otherwise be unable to tread. The students will develop a mobile app as a portal for "citizen science"; and the project engages the broader public by enabling participation in the visual classifications central to the scientific analysis. Unlike prior efforts in citizen science in astronomy, this program aims to reach citizens through their now most commonly used electronic tools (tablets and phones) and by casting much of the interaction in a more "game-like" setting using an app, rather than webpages. The students will be encouraged to participate in outreach activities, particularly to the broader Deaf public in Chicago, with the aim of sparking interest in STEM studies in yet younger citizens.This project clearly relates to NSF's mission to promote the progress of science. In addition, the "Broader Impact" portion of the project does this, and advances the national health, prosperity and welfare by helping to develop interest in, and educating, STEM activities among the next generation of diverse individuals.Cosmological simulations are becoming the backbone of analysis for a wide range of extragalactic data. These analyses are numerous, spanning our efforts to understand all observable discrete extragalactic objects, integrated direct backgrounds from X- rays to the radio, and the influence of all that structure on the observed cosmic microwave background, as well as the scientific exploitation of that wide range of signals. Simulations are central to the planning and deployment of major new facilities and experiments. As simulations develop in complexity and scope, and impact, it is paramount that they are rigorously tested against a broad range of observables. This testing is critical as a check of algorithms and simulation contents, and as a test of the physics that the simulations evince. Strong lensing by the most massive halos (from galaxies and clusters of galaxies) in the universe is a unique point of connection between cosmological simulations, and the real cosmos. Robustly predicting strong lensing, given a simulation, requires only some fairly simple ray tracing. By comparing the two largest samples of massive strong lenses against the largest existing simulations, this proposal will address unambiguously a long-standing doubt in the literature: Namely that the correspondence between real and simulated universes in this regime is poor. If the proposed comparisons refute this long-suggested concern, a major challenge to the existing model and the simulations that evoke it will be effectively retired. Conversely, if this long held problem is reinforced, then the proposed detailed examination of the statistics of lensing will illuminate why, and how simulations must be advanced to ensure correspondence. Either result will move this field forward, significantly. Comparisons between simulations and observed real samples will be made across many lens and lensing properties, testing the match or lack thereof in multiple ways, across the entire relevant redshift column, and two decades in halo mass. Such an analysis has never before been possible or attempted, and is possible only now due to rapid advances in both real strong lensing samples, and simulations.

该项目将模拟宇宙学的元素，并将其与观测结果进行比较，特别是使用充当透镜的强引力场。 目标是了解引力透镜是否可以用来了解宇宙学特性。 使这个项目成为可能的是越来越多的强引力透镜样本。 这些透镜是巨大的星系和星系团，它们非常大，它们会弯曲来自更远的背景物体并穿过透镜物体附近的光线。 研究这些透镜和透镜物体将使研究人员能够研究星系和星团的质量、暗物质的数量、遥远的物体以及源、透镜和我们之间的空间，并确定宇宙的基本特性。 该项目要回答的主要问题是：宇宙中最大质量物体（充当透镜）的特性是否与天文学家通过宇宙模拟做出的预测相匹配？如果是这样，它们可以用来理解更基本的问题。 如果没有，天文学家将更好地了解需要对他们的模拟进行哪些改进来改进它们。 由于观察到的透镜物体数量的增加，该项目现已成为可能。除了该项目的科学部分外，PI 还与来自国家聋人技术研究所的六名聋人本科生合作，作为芝加哥大学的暑期合作学生，以增加美国科学家的多样性。通过让他们在学术生涯的早期参与科学研究，该项目旨在开辟他们原本无法踏上的职业道路。学生们将开发一款移动应用程序作为“公民科学”的门户；该项目通过支持对科学分析至关重要的视觉分类来吸引更广泛的公众。与之前在天文学公民科学方面的努力不同，该计划旨在通过目前最常用的电子工具（平板电脑和手机）接触公民，并使用应用程序（而不是网页）在更“类似游戏”的环境中进行大部分互动。我们将鼓励学生参加外展活动，特别是针对芝加哥更广泛的聋人公众，目的是激发年轻公民对 STEM 研究的兴趣。该项目显然与 NSF 促进科学进步的使命相关。 此外，该项目的“更广泛影响”部分做到了这一点，并通过帮助培养下一代不同个体对 STEM 活动的兴趣和教育 STEM 活动来促进国民健康、繁荣和福利。宇宙学模拟正在成为各种河外数据分析的支柱。这些分析数量众多，涵盖了我们为了解所有可观测的离散河外物体、从 X 射线到无线电的综合直接背景、所有这些结构对观测到的宇宙微波背景的影响以及对广泛信号的科学利用所做的努力。模拟对于主要新设施和实验的规划和部署至关重要。随着模拟的复杂性、范围和影响力不断发展，最重要的是，它们要针对广泛的可观测值进行严格的测试。该测试对于算法和模拟内容的检查以及模拟所显示的物理原理的测试至关重要。宇宙中最大的光环（来自星系和星系团）的强烈透镜作用是宇宙学模拟和真实宇宙之间的独特连接点。在模拟的情况下，稳健地预测强透镜效应只需要一些相当简单的光线追踪。通过将两个最大的大规模强透镜样本与最大的现有模拟进行比较，该提议将明确解决文献中长期存在的疑问：即该体系中真实宇宙和模拟宇宙之间的对应性很差。如果所提出的比较驳斥了这一长期提出的担忧，那么对现有模型和引发该模型的模拟的重大挑战将实际上被淘汰。相反，如果这个长期存在的问题得到加强，那么对透镜效应统计数据的详细检查将阐明原因，以及如何推进模拟以确保一致性。任何一个结果都将显着推动这一领域向前发展。将在许多透镜和透镜特性上进行模拟和观察到的真实样本之间的比较，以多种方式测试其匹配或缺乏，在整个相关的红移柱和二十个光晕质量中。这样的分析以前从未可能或尝试过，并且由于真实强透镜样本和模拟的快速发展，现在才成为可能。