The Physical Properties of the Accreted Satellites of the Milky Way.

这个项目的目的是研究被吸积到银河系上的矮星系的特性，这些矮星系今天构成了银河系光晕恒星质量预算的很大一部分。我们感兴趣的主要性质是质量、重子历史（即恒星形成和化学富集历史）和矮星系的吸积时间。Mackereth等人（2019）在星系演化与组装及其环境（EAGLE）模拟中研究了类银河系星系的吸积卫星的这些特性，并认为这些卫星的质量与它们在α -铁平面上的恒星丰度模式密切相关。我们将进一步探索化学对质量和其他参数的依赖，如与中心晕的相互作用历史、粒子结合能和吸积时间，目的是探索EAGLE中化学性质与重子历史之间的理论联系。在该项目的下一阶段，通过研究EAGLE模拟获得的知识将用于描述构成银河系晕的吸积卫星的特性，并应用于远地点和WEAVE调查的数据。感兴趣的样本将在内部开发的分析技术的基础上进行选择，以确定轨道性质和星系成分的结构参数，并对调查选择效应进行校正。最终，将~10^6光晕恒星的化学动力学特性与EAGLE预测结果进行比较，将使我们能够完整地描述构成银河系光晕的恒星群的特性。

The aim of this project is to investigate the properties of dwarf galaxies that were accreted onto the Milky Way and today make up a substantial mass fraction of the stellar mass budget of its halo. The main properties of interest are mass, baryonic history (i.e., star formation and chemical enrichment histories) and accretion time of dwarf galaxies. Mackereth et al (2019) studied these properties of accreted satellites of Milky Way-like galaxies in the Evolution and Assembly of GaLaxies and their Environments (EAGLE) simulations and suggested that the masses of these satellites are strongly correlated with their stellar abundance patterns in the alpha-iron plane. We will further explore the dependence of chemistry on mass and other parameters, such as the history of interaction with the central halo, particle binding energy and accretion time with the goal of probing theoretical connections between chemical properties and baryon histories in EAGLE. In the next stage of the project the knowledge acquired from studying the EAGLE simulations will be employed in order to characterise the properties of accreted satellites that make up the Milky Way halo and applied to data from the APOGEE and WEAVE surveys. The sample of interest will be selected on the basis of analysis techniques developed in-house to determine the orbital properties and structural parameters of galactic components after correction for survey selection effects. Ultimately, comparison between the chemodynamic properties of ~10^6 Halo stars and EAGLE predictions will enable a complete characterisation of the properties of the stellar populations that comprise the Milky Way's halo.