Formation of the First Galaxies: Predictions for the Next Generation of Observatories

第一个星系的形成：对下一代天文台的预测

• 批准号: 0832662
• 负责人: Brian O'Shea
• 金额: $ 4万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-01 至 2013-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0832662&HistoricalAwards=false
• 关键词: Formation; First; Galaxies; Predictions; Next

This proposal is for a provisional allocation of time on the Blue Waters computer system, due to become operational in 2011, and for travel funds to support technical coordination by various collaborators with the Blue Waters project team and vendor technical team.The proposed work will test the hypothesis that the first galaxies were responsible for re-ionizing the early universe and the source of large amounts of metal in the intergalactic medium. The researchers also plan to predict the properties of the population of galaxies with red-shifts in the range 8 z 15 that will be observed with next-generation astronomical observing systems. It is anticipated that these predictions will aid in the interpretation of the output from the new observatories.The work will consist of large simulations using the Enzo code. The questions that will be addressed are: (1) What are the first galaxies; (2) What physical processes dominate the behavior of baryons in these galaxies; (3) When and how did re-ionization occur; and (4) What sources caused re-ionization? To answer these, the Enzo code will be extended to include: an accurate treatment of the chemo-thermal evolution of gas so that molecular clouds can form; sufficient resolution to characterize the mean properties of the molecular clouds; development of a sub-grid model for primordial and metal-enriched star formation that depends only on the mean properties of the molecular clouds; accurate incorporation of radiative transfer effects; and supernova feedback. The principal investigator is a new faculty member and the simulation code being developed should be usable by a number of other researchers beyond the project team.

这一提议是为了在2011年投入使用的Blue Waters计算机系统上临时分配时间，以及为支持Blue Waters项目团队和供应商技术团队的各种合作者进行技术协调提供旅费。这项被提议的工作将检验第一个星系负责早期宇宙再电离的假设，以及星系间介质中大量金属的来源。研究人员还计划预测在8 z 15范围内红移的星系群的特性，这将被下一代天文观测系统观测到。预计这些预测将有助于解释新天文台的输出。这项工作将包括使用Enzo代码的大型模拟。将要解决的问题是：(1)什么是第一个星系；(2)在这些星系中，什么物理过程主导了重子的行为？(3)再电离发生的时间和方式；(4)引起再电离的来源是什么？为了回答这些问题，恩佐代码将被扩展到包括：精确处理气体的化学-热演化，以便分子云的形成；足够的分辨率来表征分子云的平均性质；为原始恒星和富含金属的恒星形成建立了子网格模型，该模型仅依赖于分子云的平均性质；辐射转移效应的精确结合；还有超新星反馈。首席研究员是一名新教员，正在开发的模拟代码应该可供项目团队以外的许多其他研究人员使用。