Gas-phase Metallicity of Local Active Galactic Nuclei in the GASP and MaNGA Surveys: The Role of Ram Pressure Stripping

Abstract

Growing evidence in support of a connection between active galactic nuclei (AGN) activity and the ram pressure stripping (RPS) phenomenon has been found both observationally and theoretically in the past decades. In this work, we further explore the impact of RPS on the AGN activity by estimating the gas-phase metallicity of nuclear regions and the mass–metallicity relation of galaxies at z ≤ 0.07 and with stellar masses logM*/M⊙≥9.0 , either experiencing RPS or not. To measure oxygen abundances, we exploit Integral Field Spectroscopy data from the GASP and MaNGA surveys, photoionization models generated with the code Cloudy and the code Nebulabayes to compare models and observations. In particular, we build Cloudy models to reproduce line ratios induced by photoionization from stars, AGN, or a contribution of both. We find that the distributions of metallicity and [O iii] λ5007 luminosity of galaxies undergoing RPS are similar to the ones of undisturbed galaxies. Independently of the RPS, we do not find a correlation between stellar mass and AGN metallicity in the mass range logM*/M⊙≥10.4 , while for the star-forming galaxies we observe the well-known mass–metallicity relation between 9.0≤logM*/M⊙≤10.8 with a scatter mainly driven by the star formation rate and a plateau around logM*/M⊙∼10.5 . The gas-phase metallicity in the nuclei of AGN hosts is enhanced with respect to those of star-forming galaxies by a factor of ∼ 0.05 dex regardless of the RPS.