Evolution of the Intergalactic Medium

AST-0507521 Cen众所周知，引力不稳定性是驱动重子结构形成的主导力量。 然而，星系间介质（IGM）从星星形成的反馈过程还没有得到很好的理解，虽然在观测上的星系超风（GSW）的现象是常见的低红移星暴星系和高红移莱曼破裂星系。 在宇宙学流体动力学模拟中，对GSW和其他重要物理过程缺乏足够的处理，阻碍了对IGM演化的全面理解。 本研究将进行自适应网格细化流体动力学模拟与所有可能的相关物理过程仔细处理，更精确地计算IGM的演变，特别是，温暖的热IGM（WHIM）在低红移和莱曼α森林在中等红移。 这将产生WHIM分布的详细特征，允许未来观测确定这种状态下宇宙重子的比例。 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精确，以揭示暴胀理论的有用信息。 这项研究将建立一个适当的框架来解释关于IGM进化的庞大观测数据库，以一种物理上自洽的方式，这项工作的更广泛的影响包括继续向公众提供有效的外展计划，通过有效的渠道，如美国自然历史博物馆的罗斯海登天文馆，以及公共电视节目，如新星。

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.