SDSS-IV/MaNGA ; galaxy stellar and HI masses

We use integral-field spectroscopic measurements of gas-phase metallicity and single-dish radio measurements of total atomic gas mass to estimate the magnitude and frequency of gaseous inflows incident on star-forming galaxies. We reveal a mutual correlation between steep oxygen abundance profiles between 0.25 and 1.5Re, increased variability of metallicity between 1.25 and 1.75Re, and elevated HI content at fixed total galaxy stellar mass.

Employing a simple but intuitive inflow model, we find that galaxies with total stellar mass less than 1010.1M{sun} have local oxygen abundance profiles consistent with reinvigoration by inflows. Approximately 10%-25% of low-mass galaxies possess signatures of recent accretion, with estimated typical enhancements of approximately 10%-90% in local gas mass surface density. Higher-mass galaxies have limited evidence for such inflows.