Gas Accretion and the Disk-Halo Interface

这个项目解决了气体如何流入螺旋星系的问题，这一过程对于支持这些系统中恒星形成的漫长历史至关重要。PI和co-PI将使用自适应网格流体动力学程序ENZO对进入盘状星系的气体流动进行两系列模拟。第一个系列将包括对类似于银河系的星系晕的非常高分辨率的宇宙学模拟；目标是解决气体冷相和热相之间的界面，并确定从热相凝结的冷云是否会到达盘状物。第二个系列将模拟银盘内部和上方的垂直柱，目的是确定热不稳定性是否以及如何将冷却介质引导到银盘中。该程序还将用于构建对冷却介质中产生的发射线和吸收线的模拟观测，以便与现有的光谱数据进行比较。这项工作将部分由一名博士后研究员执行，并将包括对其进行指导。博士后、PI和共同PI将参与一个培训研究生访问中学进行互动推广计划的计划，根据模拟构建的可视化将用于天文馆表演或其他公共场所。

This project addresses the issue of how gas flows into spiral galaxies, a process essential to support the long histories of star formation in these systems. The PI and co-PI will use the adaptive-mesh hydrodynamics code Enzo to carry out two series of simulations of gas flow into disk galaxies. The first series will consist of very high resolution cosmological simulations of galaxy halos similar to that of the Milky Way; the goal is to resolve the interface between the cold and hot phases of the gas and determine whether cold clouds condensing from the hot phase make their way to the disk. The second series will simulate a vertical column in and above the galactic disk, with the goal of determining whether and how thermal instabilities serve to channel the cooling medium into the disk. The code will also be used to construct simulated observations of emission and absorption lines arising in the cooling medium, for comparison with available spectroscopic data. The work will in part be performed by, and will include the mentoring of, a postdoctoral fellow. The postdoc, PI, and co-PI will participate in a program to train graduate students to visit middle schools to conduct interactive outreach programs, and visualizations constructed from the simulations will be made available for planetarium shows or other public venues.