The Role of Gas in the Evolution of Galaxies

星系的形成和演化是现代天体物理学尚未解决的主要问题之一。天文学家希望了解星系何时开始形成，以及宇宙历史上星星的形成是如何演变的。这项建议的最终目标是通过对附近和遥远宇宙中星系的观测，对形成星系的一些主要过程形成物理上的理解。首席研究员和合作者将利用新的观测结果，包括阿塔卡马大型毫米/亚毫米阵列（阿尔马）和布雷高原干涉仪（PdBI）的观测结果，来研究一系列的课题，这些课题是提高我们对星系演化的理解所必需的。在多管齐下的战略中，该团队将研究宇宙时间内主序星星系中气体分数和耗尽时间尺度的演变，气体分数的质量依赖性，场星系中占主导地位的反馈和淬灭机制，星系流出的物理学以及低金属丰度和星暴星系中分子云的物理条件。这项研究将大大提高对星系演化的理解，阿尔马观测是研究的核心组成部分。PI还将与研究生资源推进多样性与马里兰州天文学和物理学倡议（GRAD-MAP）合作，这是一个旨在减少少数民族进入天文学和物理学研究生院所面临的障碍的计划。最后，PI将继续开发河外天文学研讨会（AWE）网站，该网站提供一套天文学概念的在线演示。

One of the principal unsolved problems in modern astrophysics is the formation and evolution of galaxies. Astronomers wish to understand when galaxies first develop, as well as how star formation evolves over the history of the universe. The ultimate goal of this proposal is to develop a physical understanding, informed by observations of galaxies in the nearby and distant universe, of some of the main processes that shape galaxies.The Principal Investigator and collaborators will use new observations, including those with the Atacama Large Millimeter/submillimeter Array (ALMA) and the Plateau de Bure Interferometer (PdBI), to study a number of topics that are required to improve our understanding of galaxy evolution. In a multi-pronged strategy, the team will study the evolution of gas fractions and depletion time scales in main sequence galaxies during cosmic time, the mass dependence of gas fractions, the dominant feedback and quenching mechanisms in field galaxies, the physics of galaxy outflows, and the physical conditions in molecular clouds in low metallicity and starburst galaxies. This research will lead to a greatly improved understanding of galaxy evolution, with ALMA observations forming a central component of the research.The PI will also work with the Graduate Resources Advancing Diversity with Maryland Astronomy and Physics initiative (GRAD-MAP), which is a program designed to lessen the barriers faced by minorities to enter astronomy and physics graduate school. Finally, the PI will continue the development of the Astronomy Workshop Extragalactic (AWE) website, which provides a suite of online demonstrations of astronomical concepts.