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

这项提议是为了临时分配将于2011年投入使用的Blue Waters计算机系统的时间，以及旅行资金，以支持不同的合作者与Blue Waters项目团队和供应商技术团队的技术协调。拟议的工作将检验这样一个假设，即第一批星系负责重新电离早期宇宙和星际介质中大量金属的来源。研究人员还计划预测将用下一代天文观测系统观测到的红移在8 z 15范围内的星系群的性质。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)第一批星系是什么；(2)在这些星系中，什么物理过程支配着重子的行为；(3)重新电离发生的时间和方式；以及(4)是什么来源引起了重新电离？为了回答这些问题，EZO程序将扩展到包括：对气体的化学热演变的准确处理，以便形成分子云；有足够的分辨率来描述分子云的平均性质；开发仅取决于分子云的平均性质的原始和富金属恒星形成的亚格子模式；准确纳入辐射转移效应；以及超新星反馈。首席研究人员是一名新的教员，正在开发的模拟代码应该可以被项目团队以外的许多其他研究人员使用。

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.