Gas Accretion and the Disk-Halo Interface

该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悠久历史至关重要。PI和co-PI将使用自适应网格流体动力学代码Enzo来进行两个系列的气体流入盘状星系的模拟。第一个系列将包括非常高分辨率的星系晕的宇宙学模拟，类似于银河系；目标是解决气体的冷相和热相之间的界面，并确定从热相冷凝的冷云是否能够到达磁盘。第二个系列将模拟银河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河盘。该代码还将用于构建在冷却介质中产生的发射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完成，并将包括他的指导。博士后、项目负责人和联合项目负责人将参加一个培训研究生访问中学进行互动推广项目的项目，并将通过模拟构建的可视化图像提供给天文馆或其他公共场所。

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.