US-France Cooperative Research: Numerical Studies of the Formation and Evolution of Galaxies

该奖项将支持哥伦比亚大学的Kevin Prendergast博士和由Evangelie Athanassoulas博士领导的法国马赛天文台的一组天文学家之间的合作研究。该项目的目标是使用多流体代码来研究星系结构和演化，以跟踪恒星、气体和暗物质的运动和相互作用。现有的代码包含了恒星的形成、演化和质量损失，以及恒星的加热和气体的辐射冷却。将两种流体代码的球形版本进行整合，得到了理论上的Faber-Jackson关系，该关系可以与在后发星团和室女座星团中观测到的椭圆相匹配。其他结果表明，中等质量的星系容易出气，而高质量的星系则不会。这可能表明普通系统和矮系统之间存在差异的一个可能原因。低质量系统可能会被导致中质量系统出气的相同过程完全破坏。在这个项目中，研究人员将继续现有代码的工作，并构建一个轴对称版本，希望从旋转星系的刺激中出现费雪-塔利关系。美国和法国的调查人员在拟议的研究领域具有重要的专业知识，该项目将受益于马赛天文台现有的特殊设施。这项工作的结果有望有助于我们对银河系结构和演化的理解。

This award will support collaborative research between Dr. Kevin Prendergast, Columbia University and a group of French astronomers from the Observatoire de Marseille, France, led by Dr. Evangelie Athanassoulas. The objective of the project is to study galactic structure and evolution using a multifluid code to follow the motions and interactions of stars, gas and dark matter. The existing code embodies star formation, evolution and mass loss, together with stellar heating and radiative cooling of the gas. Integrations with a spherical version of the two-fluid code have yielded a theoretical Faber-Jackson relation, which can be matched to observed ellipticals in the Coma and Virgo clusters. Other results indicate that galaxies of intermediate mass are subject to outgassing, while high mass systems are not. This may indicate a possible reason for the differences between ordinary and dwarf systems. Low mass systems may be entirely disrupted by the same process which leads to outgassing in systems of intermediate mass. In this project the investigators will continue the work with the existing code, and construct an axisymmetric version, in the hope that the Fisher-Tully relation will emerge from stimulations of rotating galaxies. The U.S. and French investigators have significant expertise in the area of proposed research, and the project will benefit from the special facilities available at the Marseille Observatory. The results of this work are expected to contribute to our understanding of galactic structure and evolution.