CAREER: Mapping the Fuel for Star Formation Across Cosmic History

University Of Arizona, Tucson AZ

Investigators

Abstract

Molecular gas is the raw material for star formation in galaxies. To understand how the total stellar mass of the universe was formed, we must understand how the fuel for star formation has been assembled and consumed over cosmic history. This project will measure the molecular gas content of the universe over most of its history, beginning more than 10 billion years ago, using the "intensity mapping" technique. Intensity mapping aggregates the signal from numerous undetectable galaxies to capture the distribution of molecular gas through three-dimensional volumes of the universe, across the sky and back into cosmic history. To achieve this goal, the team will mine the archives of the largest radio telescopes and conduct new experiments using advanced instruments. This project includes a focused effort to improve the teaching of important science topics through radio technology, from non-science undergraduates through astronomy graduate students. The implementation of this work is centered on paid research experiences for cohorts of STEM majors who are at risk of leaving the university. The proposed research will measure the growth and consumption of molecular gas across the last 10 billion years of cosmic history. Molecular gas is the raw material that powers the process of star formation in galaxies, and a chart of its history can contribute significantly to our understanding of the process of galaxy formation. Unlike the stars themselves, the cold gas from which they form is very faint and hard to observe beyond the nearby universe. The proposed project will overcome this challenge through the technique of "intensity mapping," in which the light from tens of thousands of galaxies is integrated together to generate a detectable signal despite the fact that few of the galaxies can be seen individually. The team will use a variety of data sources to assemble a comprehensive picture of the molecular fuel, including archival data from radio telescope arrays and experiments designed specifically for this type of measurement. The work will culminate in a large program of intensity mapping with the TIME multi-pixel spectrometer, which will be installed on the 12m ALMA prototype antenna of the Arizona Radio Observatory. As part of this program, the PI will use radio science and digital signal processing hardware to enhance the teaching of critical science topics at all levels, from undergraduate general education to upper division majors and graduate students. These activities will provide research experience to cohorts of students from the university's ASEMS program, which increases the persistence of STEM majors, particularly those who are first-in-family students, from low-income households, community college transfers, and/or members of groups underrepresented in STEM.