Theoretical Studies of the Structure and Dynamics of Cloudy Interstellar Medium Spiral Galaxies

将对星系气体流动动力学这一重要经典问题以及气体在星系结构和动力学中所起的作用进行理论和计算研究。正常的和条形的螺旋星系将是近年来大量改进和详细的观测数据研究的主要重点，这些数据现在使新的确定性测试和与观测的比较成为可能。在多管齐下的研究计划中，云-粒子星系气体动力学和连续气体动力学是必不可少的。我们将同时研究完整星系盘的详细模拟和选定局部区域的更高分辨率模拟，以更好地理解宏大设计和局部螺旋臂形态之间的关系。云层间的自引力效应、磁场相互作用和恒星形成过程也将是主要的关注领域。云的局部有效粘性是由云-粒子模拟确定的，并被用来产生星系气体流动的广义连续气体动力学描述，该描述适当地模拟了多云星际介质(ISM)的平均输运特性。计算模拟在这项工作中的应用是目前一个具有重要意义的课题，也是一个单独的主要推动力领域。模拟的高空间分辨率将被用来与观测进行明确的比较，并为基于局部稳定性分析的理论预测提供仔细的测试。

Theoretical and computational studies on the important classic problem of the dynamics of galactic gas flows and the roles played by the gas in the structure and dynamics of galaxies will be carried out. Normal and barred spiral galaxies will be a major focus of the research of the wealth of improved and detailed observational data that has become available in recent years, now making possible new definitive tests and comparisons with observations. Cloud-particle galactic gas dynamics and continuum gas dynamics are essential in the multipronged program of research. Detailed simulations of full galactic disks and higher resolution simulations of selected local regions will be studied in parallel to better understand the relationship between grand design and local spiral arm morphologies. The effects of self gravitation among clouds, magnetic field interactions, and star formation processes will also be primary areas of focus. The local effective viscosity of the cloud is determined from the cloud-particle simulations and used to produce a generalized continuum gas dynamical description of galactic gas flows that properly simulates the average transport properties of the cloudy interstellar medium (ISM). The utilization of computational simulation in this work is a topic of great significance at the present time and is a separate major thrust area. The high spatial resolution of the simulations will be utilized to make definitive comparisons with observations and provide careful tests for theoretical predictions based on local stability analyses.