The Environmental Dependence of Gas-Phase Metallicities

摘要：恒星和星际介质中的化学丰度测量为宇宙时代星系的恒星形成和质量聚集历史提供了强有力的诊断。不同化学物种的原子、离子或分子在宇宙中追踪不同的热力学阶段和物质分布的演化阶段。此外，不同的化学元素对星系及其环境中不同的动力学过程也是敏感的。在这个博士项目中，学生将分析曾经运行过的最大的宇宙流体动力学模拟(Horizon Run 5)，以(I)量化不同宇宙网络环境结构和亚结构中的总体金属含量如何被用来追踪高红移星系的质量组装历史；以及(Ii)通过详细表征不同宇宙网络环境在高红移时结构和亚结构中的金属丰度的演化，从宇宙学的角度理解观测到的质量-金属丰度关系的起源，它与红移的演化，以及它的散射的起源。这一博士项目可能会为詹姆斯·韦伯太空望远镜(JWST)和暗能量光谱仪(DESI)即将进行的观测，以及未来的NASA太空任务，如南希·格雷斯·罗曼太空望远镜和SPHEREx提供一个理论框架。

Abstract: Chemical abundance measurements in the stars and interstellar medium provide a powerful diagnostic of the star formation and mass assembly history of galaxies across cosmic times. Atoms, ions, or molecules of different chemical species trace different thermodynamical phases and evolutionary stages of the matter distribution in the cosmos. Furthermore, different chemical elements are also sensitive to different dynamical processes within galaxies and their environment. In this PhD project, the student will analyse the largest cosmological hydrodynamical simulation of the Universe that has ever been run (Horizon Run 5) to (i) quantify how the overall metal content within structures and substructures of different cosmic web environments can be used to trace the mass assembly history of galaxies at high redshift; and (ii) understand the origin of the observed mass-metallicity relation, its evolution with redshift, and the origin of its scatter from a cosmological perspective, by characterizing in detail the evolution of the metallicity within structures and substructures of different cosmic web environments at high redshift. This PhD project might provide a theoretical framework for upcoming observations from the James Webb Space Telescope (JWST) and the Dark Energy Spectroscopic Instrument (DESI), and future NASA space missions like the Nancy Grace Roman Space Telescope and SPHEREx.