Evolution of the Intergalactic Medium

众所周知，引力不稳定性是重子结构形成的主要驱动力。然而，恒星形成对星际介质(IGM)的反馈过程还不是很清楚，尽管从观测上看，星系超风(GSW)现象在低红移星暴星系和高红移Lyman破缺星系中都很常见。在宇宙流体动力学模拟中，缺乏对GSW和其他重要物理过程的适当处理，阻碍了对IGM演化的充分理解。这项研究将进行自适应网格加密流体动力学模拟，仔细处理所有可能的相关物理过程，以更准确地计算IGM的演变，特别是低红移的暖热IGM(Whim)和中等红移的Lyman Alpha森林。这将产生对突发奇想分布的详细描述，从而允许未来观测确定处于这种状态的宇宙重子的比例。它还将有助于量化系统误差，再次允许未来对物质功率谱的观测约束足够准确，以揭示通胀理论。这项研究将建立一个足够的框架，以物理上自我一致的方式解释关于IGM进化的庞大观测数据库。这项工作的广泛影响包括继续有效地向公众推广计划，使用通过有效渠道呈现的可视化，如在美国自然历史博物馆的Rose-Hayden天文馆，以及公共电视节目，如Nova。

AST-0507521CenIt is well established that gravitational instability is the dominant force driving the formation of baryonic structures. However, feedback processes on the intergalactic medium (IGM) from star formation are not well understood, although observationally the phenomenon of galactic super-winds (GSW) is common in both low redshift starburst galaxies and high redshift Lyman break galaxies. Lack of an adequate treatment of GSW and other important physical processes in cosmological hydrodynamic simulations hampers a full understanding of the evolution of the IGM. This research will carry out adaptive mesh refinement hydrodynamic simulations with all likely relevant physical processes carefully treated, to compute more precisely the evolution of the IGM, and specifically, the warm-hot IGM (WHIM) at low redshift and the Lyman alpha forest at moderate redshift. This will produce a detailed characterization of the distribution of the WHIM, allowing future observational determination of the fraction of the cosmic baryons in this state. It will also help to quantify systematic errors, again allowing future observational constraints on the matter power spectrum to be accurate enough to shed useful light on inflationary theories. This research will set up an adequate framework to interpret the vast observational database on evolution of the IGM, in a physically self-consistent fashion.Broader impacts of this work include continuing an effective outreach program to the general public, using visualizations presented through effective channels, such as at the Rose-Hayden Planetarium of the American Museum of Natural History, and public television programs such as Nova.