Constraining Quenching Mechanisms: HI in Low-Mass Active Galaxies

What causes star formation to shut down or quench? Active galactic nuclei (AGN) have been proposed as a possible mechanism for either heating or removing gas from the centers of galaxies, which would prevent further stars from forming. We study the content and distribution of the future reservoir of star formation fuel, the neutral atomic hydrogen (HI) gas, in a sample of low-mass galaxies with optically-selected AGN to determine what effects an AGN might have on a galaxy’s star formation. Previous studies found that low-mass galaxies hosting AGN were HI deficient in comparison with non-AGN galaxies. We have obtained interferometric observations of 10 galaxies using the Very Large Array (VLA) to study the HI distribution and kinematics in low-mass galaxies hosting AGN. With a 14” angular resolution and a 16’ beam, the VLA in C-configuration allows us to study the gas distribution within a galaxy and in the galaxy environment. We selected our sample of galaxies from the Sloan Digital Sky Survey IV Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey based on cuts in stellar mass, r-band absolute magnitude, and star formation rate. Out of 2133 low-mass galaxies in the MaNGA MPL-8 data release, 74 had emission line ratios suggestive of AGN activity and 25 of those had low star formation rates. We present the results of our HI observations of 10 galaxies in this sample.