论文标题
我们银河系的自洽模型
Self-consistent models of our Galaxy
论文作者
论文摘要
引入并使用了新的恒星光盘模型，以构建我们银河系的自洽模型。该模型是由指定四个恒星盘（三个薄盘时代群和一个厚的圆盘）的参数定义的，该参数是基于动作的分布函数（DFS）F（j），球体凸起和球形恒星和黑暗的光环。从这些DF以及特定的气体分布中，我们解决了恒星和暗物质的密度以及它们产生的潜力。主要的观察约束是带有GAIA RVS数据的恒星的运动学，以及太阳上方的圆柱中的恒星密度。该模型预测了整个银河系中恒星和暗物质的密度和运动学。我们确定了巴元中心之前的深色光环的结构。恒星成分的DFS的简单扩展包括化学，使该模型可以重现观察到星系化学在（R，Z）平面中变化的方式。令人惊讶的是，数据表明高α恒星局限于J_z> 〜50 kpc km/s的轨道。用于创建模型的代码可在GitHub上获得。
A new class of models of stellar discs is introduced and used to build a self-consistent model of our Galaxy. The model is defined by the parameters that specify the action-based distribution functions (DFs) f(J) of four stellar discs (three thin-disc age cohorts and a thick disc), spheroidal bulge and spheroidal stellar and dark haloes. From these DFs plus a specified distribution of gas, we solve for the densities of stars and dark matter and the potential they generate. The principal observational constraints are the kinematics of stars with Gaia RVS data and the density of stars in the column above the Sun. The model predicts the density and kinematics of stars and dark matter throughout the Galaxy. We determine the structure of the dark halo prior to the infall of baryons. A simple extension of the DFs of stellar components to include chemistry allows the model to reproduce the way the Galaxy's chemistry is observed to vary in the (R,z) plane. Surprisingly, the data indicate that high-alpha stars are confined to orbits with J_z >~ 50 kpc km/s. The code used to create the model is available on Github.
