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博士与法国马赛天文台的一组法国天文学家之间的合作研究，该小组由Evangelie Athan assoulas博士领导。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。现有的代码包含恒星的形成、演化和质量损失，以及恒星加热和气体的辐射冷却。用双流体程序的球形版本进行积分，得到了一个理论上的法伯-杰克逊关系，它可以与观测到的彗星团和室女座星团中的椭圆体相匹配。其他结果表明，中等质量的星系容易放出气体，而高质量的星系则不会。这可能表明了普通星系和矮星系统之间存在差异的可能原因。低质量系统可能会被同样的过程完全扰乱，这会导致中等质量系统放出气体。在这个项目中，研究人员将继续使用现有的代码进行工作，并构建一个轴对称版本，希望费希尔-塔利关系将从旋转星系的刺激中浮现出来。美国和法国的调查人员在拟议的研究领域拥有丰富的专业知识，该项目将受益于马赛天文台的特殊设施。这项工作的结果有望有助于我们理解银河系的结构和演化。

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.