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中尚未解决的主要问题之一。天文学家希望了解星系最初形成的时间，以及恒星形成是如何在宇宙历史上演化的。这一提议的最终目标是通过对近宇宙和远宇宙中星系的观测，建立对形成星系的一些主要过程的物理理解。主要研究者和合作者将使用新的观测，包括阿塔卡马大毫米/亚毫米阵列(ALMA)和高原德布鲁干涉仪(PdBI)，来研究一些提高我们对星系演化的理解所需的课题。在一个多管齐下的战略中，该团队将研究宇宙时间内主序星系中气体部分和耗尽时间尺度的演变，气体部分的质量依赖，场星系中的主要反馈和猝灭机制，星系外流的物理学，以及低金属度和恒星爆发星系中分子云的物理条件。这项研究将极大地改善对星系演化的理解，ALMA观测是这项研究的核心组成部分。PI还将与研究生资源促进多样性与马里兰天文和物理倡议(Grad-MAP)合作，这是一个旨在减少少数族裔进入天文和物理研究生院的障碍的计划。最后，国际天文学联合会将继续开发天文工作坊银河系外(AWE)网站，该网站提供一套天文概念的在线演示。

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.