On the Relation Between Galaxies and Dark Matter Halos

论星系与暗物质晕的关系

• 批准号: 1612085
• 负责人: Idit Zehavi
• 金额: $ 40.25万
• 依托单位: Case Western Reserve University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1612085&HistoricalAwards=false
• 关键词: Relation; Between; Galaxies; Dark; Matter

Dark matter, which accounts for about 85% of all mass, is the dominant driver of structure formation in the Universe, but the nature of dark matter currently is unknown. Galaxies, containing visible, baryonic matter in stars and gas, are embedded in vast dark matter halos. ("Baryonic matter" in the Universe primarily consists of protons and neutrons, and the chemical elements based on those particles.) Galaxies, therefore, can be used as visible probes of dark matter's role in the formation and evolution of large-scale structure in the Universe, a fundamental problem in modern cosmology. This project aims to improve our understanding of galaxy assembly and the relationship between dark and baryonic matter. The researchers will expand and improve simulations and statistical tools used to understand the connection between galaxies and their dark matter halos. They will study the influence of environment and cosmic time on the properties of galaxies in dark matter halos. They will create realistic mock galaxy catalogs that will be essential for a better interpretation of upcoming large galaxy surveys. The project will support the mentoring and active involvement of both graduate and undergraduate students in the research program. The PI will also expand a partnership with the planetarium at the Cleveland Museum of Natural History, providing a unique opportunity for undergraduate interns and enriching the public understanding of the science from galaxy surveys.Halo occupation modeling is a powerful theoretical tool to interpret galaxy clustering measurements and constrain the relation between galaxies and dark matter. A standard assumption made in these probabilistic models is that the mass of the dark matter halo fully determines the properties of the galaxies contained in it. This project will extend the modeling approach to include cosmic evolution and environmental dependence, two crucial aspects that are currently missing. First, the evolution of the halo occupation models will be studied using semi-analytic galaxy formation models. The dependence of these models on the large-scale environment of the galaxies will be explored using both semi-analytic models and hydrodynamical simulations. These two studies will then be combined to examine the evolution of the environment trends and the environment dependence of the evolution. Finally, this extended modeling approach will be applied on simulated and real data from SDSS.

暗物质约占所有质量的85%，是宇宙结构形成的主要驱动力，但目前暗物质的性质尚不清楚。星系团包含恒星和气体中可见的重子物质，它们嵌入在巨大的暗物质晕中。（宇宙中的“重子物质”主要由质子和中子以及基于这些粒子的化学元素组成。因此，伽利略可以作为暗物质在宇宙大尺度结构的形成和演化中的作用的可见探针，这是现代宇宙学的一个基本问题。 该项目旨在提高我们对星系组装以及暗物质和重子物质之间关系的理解。研究人员将扩展和改进用于理解星系与其暗物质晕之间联系的模拟和统计工具。他们将研究环境和宇宙时间对暗物质晕中星系性质的影响。他们将创建逼真的模拟星系目录，这对于更好地解释即将到来的大型星系调查至关重要。该项目将支持研究生和本科生的指导和积极参与研究计划。PI还将扩大与克利夫兰自然历史博物馆天文馆的合作伙伴关系，为本科生实习生提供一个独特的机会，并丰富公众对星系调查科学的理解。Halo occupation modeling是一个强大的理论工具，可以解释星系团的测量结果，并限制星系和暗物质之间的关系。这些概率模型中的一个标准假设是暗物质晕的质量完全决定了其中包含的星系的性质。该项目将扩展建模方法，以包括宇宙演化和环境依赖性，这两个关键方面目前缺失。首先，将使用半解析星系形成模型研究晕占据模型的演化。这些模型对星系大尺度环境的依赖性将使用半解析模型和流体动力学模拟进行探索。然后将这两项研究结合起来，研究环境的演变趋势和演变的环境依赖性。最后，这种扩展的建模方法将应用于模拟和真实的数据从SDSS。