Formation of Dwarf Galaxies

奎恩博士和他的团队将修改他们的光滑粒子流体动力学代码，通过提高分辨率并包括对尘埃和稠密气体的处理，来跟踪矮小星系的形成。该代码跟踪暗物质和气体的引力坍塌，并跟踪气体的加热和冷却，以确定它何时应该形成新的恒星。改进将包括跟踪尘埃和氢分子的形成和破坏的近似值，从而确定当气体温度降至10000 K以下时的气体冷却。该近似值将通过与孤立的银河系和矮星系统的模拟比较来测试和调整。然后，该代码将被用来检查恒星形成何时在质量最低的暗晕中熄灭，使它们没有任何恒星形成可见的星系。通过放大更大尺度模拟的一个有趣区域，并以更高的分辨率跟踪该区域的发展，星系将被置于其宇宙学背景中。模型的模拟观测将被生成，用于与观测到的星系进行比较。研究生将通过参与研究来接受培训。该团队将继续与华盛顿大学“Pre-MAP”项目的本科生合作：该项目由理科研究生管理，旨在吸引未被充分代表的学生进入理科专业。

Dr Quinn and his team will modify their smoothed-particle hydrodynamic code to follow the formation of dwarf galaxies, by improving the resolution and including a treatment of dust and dense gas. The code follows the gravitational collapse of both dark matter and gas, and tracks heating and cooling of the gas to determine when it should form new stars. Improvements will include an approximation to follow the formation and destruction of dust and hydrogen molecules, and thus determine the gas cooling as the gas temperature drops below 10,000 K. This approximation will be tested and adjusted by comparing simulations with isolated Milky-Way-like galaxies and dwarf systems. The code will then be used to examine when star formation is quenched in the lowest-mass dark halos, leaving them without any stars to form a visible galaxy. Galaxies will be placed in their cosmological context by zooming-in on an interesting region of a larger-scale simulation, and following the development of that region at higher resolution. Simulated observations of the models will be generated, for comparison to observed galaxies.A graduate student will be trained by participating in the research. The team will continue its work with undergraduates in the University of Washington's "pre-map" program: this program is managed by science graduate students, and aims to attract under-represented students into science majors.