Formation of Dwarf Galaxies

奎因博士和他的团队将修改他们的光滑粒子流体力学代码，通过提高分辨率，包括对尘埃和致密气体的处理，来跟踪矮星系的形成。该代码遵循暗物质和气体的引力坍缩，并跟踪气体的加热和冷却，以确定何时应该形成新的恒星。改进将包括近似跟踪尘埃和氢分子的形成和破坏，从而确定气体温度降至10,000 K以下时的气体冷却。这个近似将通过与孤立的类似银河系的星系和矮星系的模拟进行比较来测试和调整。然后，该代码将用于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星系。通过放大一个更大规模模拟的有趣区域，并以更高的分辨率跟踪该区域的发展，星系将被置于它们的宇宙学背景中。将生成模型的模拟观测结果，以便与观测到的星系进行比较。研究生将通过参与研究而得到训练。该团队将继续与华盛顿大学“预地图”项目的本科生合作：该项目由科学研究生管理，旨在吸引代表性不足的学生进入科学专业。

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.