Behind a Curtain of Dust - The Evolution of Luminous Infrared Galaxies

Research Project, 2019 – 2022

Luminous infrared galaxies (LIRGs) emit a significant fraction of their bolometric luminosity in the far-infrared. They are often interacting systems that are mainly powered by extreme bursts of star formation and/or Active Galactic Nuclei (AGNs)(accreting supermassive black holes (SMBHs)) in their centers. LIRGs are the closest examples of rapid evolution in galaxies and a detailed study of LIRGs is critical for our understanding of the cosmic evolution of galaxies and black holes. LIRGs have deeply obscured centers that are unreachable at optical, IR and even X-ray wavelengths. These hidden nuclei are therefore a largely unknown phase of the growth of central regions with their SMBHs. Obscured AGNs can ultimately provide the best constraints on the AGN duty cycle, give the full range of environments and astrophysical processes that drive the growth of SMBHs, and help to complete the connections between the host galaxy and SMBH. In this project we use mm and submm observational methods to reach behind the curtain of dust in the most obscured centers of LIRGs, allowing us to undertake groundbreaking studies of heretofore hidden rapid evolutionary phases of galaxy nuclei. We use molecules as tools to probe the buried activity. We have developed new astrochemical and isotopic methods that will address the nature of primarily near-field obscured AGNs/starbursts and their associated molecular inflows and outflows.