The Milky Way's disk in the age of Gaia

我建议研究银河系圆盘的性质，并由此推断我们在宇宙中的家园是如何在宇宙时间内形成和演化的。经过一个世纪的详细研究，人们对银河系的许多最基本的属性仍然知之甚少。这包括它的质量，这个质量是如何从中心到外围分布的，其中有多少是暗物质，有多少恒星是在不同的时期形成的，具有什么化学性质，以及什么螺旋结构-当我们观察其他星系时-看起来是什么螺旋结构-它对恒星的运动有什么影响。测量大量恒星的距离、运动、年龄和化学丰度的新的恒星调查正在进行中，这将极大地扩展研究银河系性质的可用数据。*我将确定银河系大部分圆盘上恒星的空间、运动学和年龄分布，以及这些分布如何依赖于化学丰度。这将通过来自不同类型恒星的反馈来阐明恒星的形成和化学富集化的过程，并为我们提供关于恒星盘组成的详细图像。我还将使用恒星的运动来确定通过其对恒星轨道的引力来确定质量的整体分布，以及如何将这些质量分为普通物质(恒星和气体)和暗物质。最后，我将研究恒星运动与简单的光滑质量分布模型的偏差，以确定螺旋结构、中心杆和其他类型的非轴对称、含时扰动的影响。通过这些研究的结合，这项工作将为星系形成和暗物质的物理学提供重要的新见解。

I propose to investigate the properties of the Milky Way's disk and from this deduce how our home in the Universe formed and evolved over cosmic time. After a century of detailed study, many of the most basic properties of the Milky Way are still poorly understood. This includes its mass, how this mass is distributed from the center to the outskirts and how much of it is dark matter, how many stars are formed at different epochs and with what chemical properties, and what spiral structure---so clear when we look at other galaxies---looks like in the Milky Way and what effect it has on the motions of stars. New stellar surveys that measure the distances, motions, ages, and chemical abundances of large numbers of stars are being conducted now that will vastly expand the available data for investigating the properties of the Milky Way.******I will determine the spatial, kinematic, and age distributions of stars over a large part of the Milky Way's disk and how these depend on chemical abundances. This will elucidate the processes of star formation, chemical enrichment through feedback from different kinds of stars, and provide us with a detailed picture of the stellar make-up of the disk. I will also use the motions of stars to determine the overall distribution of mass through its gravitational pull on stellar orbits and how this mass is divided into ordinary (stars and gas) and dark matter. Finally, I will investigate the deviations in the stellar motions from simple smooth models for the mass distribution to determine the influence of spiral structure, the central bar, and other kinds of non-axisymmetryc, time-dependent perturbations. Through the combination of these investigations, this work will provide important new insights into the physics of galaxy formation and dark matter.**