Collaborative Research: The Circumgalactic Medium: Understanding Observations from Theory

合作研究：环绕银河介质：从理论中理解观察结果

• 批准号: 1517831
• 负责人: Jane Charlton
• 金额: $ 12.95万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1517831&HistoricalAwards=false
• 关键词: Collaborative; Research; Circumgalactic; Medium; Understanding

Precisely how galaxies initially form and how they change throughout their lifetimes are among the least understood problems in astrophysics, and understanding the formation and life cycle of galaxies is key to developing the broadest astronomical perspective on how the Universe evolved to its present state. Many projects are centered on unraveling these mysteries. This project is focused on understanding the circumgalactic medium (CGM) to uncover its role in the life cycle of galaxies.PI Churchill will expand his previous Broader Impact program based upon his course "Into the Final Frontier." This course links students to Space Port America and the growing aerospace and tourism industry rapidly growing in Las Cruces, New Mexico. Special emphasis is placed on forging STEM related opportunities for minority students, which comprise 45% of New Mexico State's student population. Two graduate students will be supported in New Mexico. PI Charlton plans to transform her successful science fiction, interactive, web astronomy course into a video game to teach K--12 students, while achieving STEM astronomy standards for the state of Pennsylvania. This project will support two pre-selected skilled and talented students to construct the game and integrate it into local schools. One graduate student will be supported in Pennsylvania.The CGM is understood through observations and analysis of absorption lines in the spectra of quasars. However, being blind to the actual properties of the absorbing gas, present day analysis methods are uncalibrated. That is, our cumulative knowledge of the CGM and its role in galaxy evolution is based upon a host of implicit and explicit assumptions that remain untested or quantified. Using the Eulerian hydrodynamic N-body cosmological simulation code hydroART, the team will use the quasar absorption line technique, coupled with direct analysis of the simulations, to study highly-detailed simulated galaxies with various star formation and feedback physical models. The galaxies will range in viral halo mass from 10.5 log(M/Msun) 12.5 and in redshift from z ~ 0-3. The team aims to address these questions: (1) What is the relationship between the gas phase structures in and surrounding galaxies and the physical model for star formation and stellar feedback? (2) How well do models that yield galaxies matching global galaxy properties also match the observed properties of the gaseous reservoirs? (3) How does the CGM regulate the baryon cycle and galaxy evolution? (4) Do current analysis methods of absorption lines yield inferred gas properties (metallicities, spatial-kinematics distributions, gas phases, and gas reservoir masses) that are consistent with the gas being probed in the simulations? (5) What are the quantitative relationships between inferred gas properties from observational analysis and the gas actually giving rise to the absorption? (6) What are the implications and how do they change our understanding of the baryon cycle and galaxy evolution?

确切地说，星系如何形成以及它们在一生中的变化是什么是天体物理学中最知名的问题之一，了解星系的形成和生命周期是发展宇宙如何发展到当前状态的最广泛的天文学观点的关键。 许多项目集中在揭开这些谜团。 该项目的重点是理解环境媒介（CGM），以揭示其在星系生命周期中的作用。PIChurchill将根据其“最终前沿”的课程扩大他以前的更广泛的影响计划。 本课程将学生与美国太空港口以及新墨西哥州拉斯克鲁塞斯迅速发展的航空航天和旅游业的发展相关联。 特别重点是为少数民族学生提供与STEM相关的机会，占新墨西哥州学生人数的45％。 两名研究生将在新墨西哥州得到支持。 皮查尔顿（Pi Charlton）计划将她成功的科幻小说，互动，网络天文学课程转变为一个视频游戏，以教导K-12学生，同时为宾夕法尼亚州实现STEM天文学标准。该项目将支持两个预先选择的熟练和才华横溢的学生来构建游戏并将其集成到当地学校。 一名研究生将在宾夕法尼亚州得到支持。通过观察和分析类星体光谱中的吸收线，可以理解CGM。 然而，对吸收气体的实际特性视而不见，目前的分析方法未校准。 也就是说，我们对CGM的累积知识及其在星系演化中的作用是基于一系列隐式和明确的假设，这些假设尚未经过测试或量化。 使用Eulerian流体动力N体宇宙学仿真代码HYDROART，该团队将使用类星体吸收线技术，再加上对模拟的直接分析，研究具有各种恒星形成和反馈物理模型的高度详细的模拟星系。星系的病毒光环质量范围从10.5 log（m/msun）12.5和Z〜0-3的红移。 该团队的目的是解决以下问题：（1）星系中和周围的气相结构与恒星形成和恒星反馈的物理模型之间的关系是什么？ （2）产生星系与全局星系性能的模型的模型如何匹配气态储层的观察到的特性？ （3）CGM如何调节重子循环和星系演化？ （4）当前的吸收线分析方法是否会产生与与模拟中探测的气体一致的气体性能（金属率，空间 - 基因模型分布，气相和气体储量）？ （5）观察性分析中推断出的气体性能与实际引起吸收的气体之间的定量关系是什么？ （6）含义是什么，它们如何改变我们对重子循环和星系进化的理解？