2024/06/02 by David V. Stark, Stark, David V., Sarah Tuttle +5
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Scientific Research and Discoveries #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2406.00635
openalex publication_date 2024/06/02 · openalex created_date 2024/06/06 · openalex updated_date 2026/07/28
By combining newly obtained deep GBT 21cm observations with optical spectroscopic data, we present an analysis of the gas content of BreakBRD galaxies, a population denoted by their blue star-forming centers and red quenched disks that do not appear to follow the typical inside-out evolution of spiral galaxies. We confirm previous results that the neutral atomic hydrogen (HI) gas fractions of BreakBRDs are on-average lower than those of typical galaxies on the star-forming sequence (SFS), and find that their \ionH1 fractions are generally higher than Green Valley (GV) galaxies. HI depletion times for BreakBRDs are roughly an order of magnitude lower than those of SFS galaxies, in stark contrast with GV galaxies that typically have much longer depletion times than SFS galaxies. The nuclear gas-phase metallicities of BreakBRDs have a broader distribution than SFS galaxies and are skewed towards slightly above-average values. BreakBRDs are systematically offset from the Baryonic Tully-Fisher Relation towards lower baryonic mass at a given rotation velocity. They also have higher typical HI asymmetries than SFS galaxies, and of those galaxies with spatially resolved gas velocity fields from the SDSS-IV MaNGA survey, two-thirds are either highly distorted or completely misaligned relative to the stellar disk. Evidence supports a scenario where BreakBRDs are in an early phase of quenching, and there is mixed evidence that their behavior is related to past merger activity.