Directly Testing the Presence of Large-Scale Multiphase Flows in the Galactic Halo

直接测试银河晕中是否存在大规模多相流

• 批准号: 1312888
• 负责人: Greg Bryan
• 金额: $ 36.34万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1312888&HistoricalAwards=false
• 关键词: Directly; Testing; Presence; Large; Scale

The circumgalactic medium (CGM), the gas reservoir outside galaxies, mediates the interaction between galaxies and the intergalactic medium, where most of the baryonic matter in the universe resides. Its structure and kinematics influence star formation and the growth of galaxies; but knowledge of the CGM remains limited both observationally and theoretically. The proposers of this project will combine simulations and observations of the CGM to constrain theories of galaxy formation. In the first part of the project, the team will develop new computational schemes for selectively improving resolution in adaptive mesh cosmological simulations and for using "active particles" to model the stellar component including momentum feedback from supernova explosions. They will use this approach to examine the dynamic evolution of halo gas in a cosmological context as it is integrated into a galactic disk. In the second part, the team will devise quantitative measures describing the distributions of gas components in physical and kinematic space. They will use these measures to compare high resolution simulations with multi-wavelength observations, test theories of gas accretion, and determine whether large, organized flows are present in the halo of the Milky Way. The project will support the work of a graduate student. Three-dimensional visualizations of the simulations will be produced and displayed at astronomy outreach events in New York City and at the American Museum of Natural History; and team members will participate in an ongoing program at Columbia University to bring graduate students and postdocs to New York middle schools.

环星系介质（CGM）是星系外的气体储存库，是星系与星系际介质相互作用的媒介，宇宙中大部分重子物质都存在于星系际介质中。它的结构和运动学影响星星的形成和星系的生长，但知识的CGM仍然有限的观测和理论。该项目的提议者将联合收割机的模拟和CGM的观测结合起来，以限制星系形成的理论。在该项目的第一部分，该团队将开发新的计算方案，以选择性地提高自适应网格宇宙学模拟的分辨率，并使用“活性粒子”来模拟恒星成分，包括超新星爆炸的动量反馈。他们将使用这种方法来研究晕气体在宇宙学背景下的动态演化，因为它被整合到星系盘中。在第二部分中，该团队将设计描述气体成分在物理和运动学空间中分布的定量措施。他们将使用这些措施来比较高分辨率模拟与多波长观测，测试气体吸积理论，并确定银河系晕中是否存在大型有组织的流动。该项目将支持一名研究生的工作。模拟的三维可视化将在纽约市和美国自然历史博物馆的天文学外展活动中制作和展示;团队成员将参加哥伦比亚大学正在进行的一项计划，将研究生和博士后带到纽约中学。