Uncovering the Origin and Evolution of Dwarf Galaxies

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

A longstanding problem in astrophysics is to understand how galaxies form and develop throughout their lifetimes. Such understanding is necessary to uncover the history of our Universe and to gain insight into the origin of our own Milky Way Galaxy. Many research projects are centered on unraveling these mysteries. Observations of nearby dwarf galaxies and of very distant galaxies hold clues about the nature of galaxy formation during the first billion years of the Universe, and these first galaxies are being detected by the Hubble Space Telescope and will be further elucidated with the commissioning of the James Webb Space Telescope in 2018. To accurately interpret and connect these nearby and very distant galaxy observations, precise computer simulations that consider the entire star formation history are essential. The purpose of this project is to make detailed computer simulations of the formation process of nearby dwarf and distant ultra-diffuse galaxies. These simulations will track the complete star formation history of dwarf galaxies including their earliest stellar and galactic ancestors. This project meets the national need to develop US scientific leadership in astrophysics. This project will also strengthen the US science workforce by directly training students in computational astrophysics, high performance computing, and software engineering, which will enable these students to excel in a competitive job market. In addition, the investigators' research activities will be integrated into the teaching of astrophysics in K--12 schools and other public venues, such as planetariums, television shows, and online learning environments, where the audience can digest the latest advances in computational astrophysics in a visual and intuitive manner. More technically, this project has the following goals: (1) to explore formation scenarios for ultra-diffuse galaxies in cluster environments and to determine whether they are related to the formation sequence of dwarf spheroidal galaxies; (2) to construct novel, efficient, and accurate methods for radiation transport; (3) to correlate the high-redshift environment of dwarf galaxy formation and evolution to present-day characteristics---star formation histories, metallicity distribution functions, stellar kinematics, and [alpha/Fe] vs. [Fe/H] evolution; and (4) to determine the chemical connection between the first stars and metal-poor stars in dwarf galaxies. This project will support the development of a hybrid radiation transport solver that incorporates the advantages of both ray tracing methods and moment methods. This method will be utilized in a suite of radiation hydrodynamics simulations of isolated dwarf galaxies, following their complete star formation, starting with individual massive metal-free stars. The simulation data produced during the course of this project, as well as various data products, will be made publicly available through the nascent National Data Service. These data will be usable by the astrophysical research community and will enable researchers to address a much broader range of questions than this project alone.