Spatially resolved gas-phase metallicity in Seyfert galaxies

We explore the relations between the gas-phase metallicity radial profiles (few hundred inner parsec) and multiple galaxy properties for 15 Seyfert galaxies from the active galactic nuclei integral field spectroscopy sample using optical integral field unit observations from Gemini Multi-Object Spectrograph (GMOS) and Multi Unit Spectroscopic Explorer (MUSE) processed archival data. The data were selected at z ≲ 0.013 within black hole mass range 6 < log (MBH/M⊙) < 9 with moderate 14-150-keV X-ray luminosities [42 ≲ log LX(erg s-1) ≲ 44]. We estimated the gas-phase metallicity using the strong-line methods and found mean values for the oxygen-dependent (Z ∼ 0.75 Z⊙) and nitrogen-dependent (Z ∼ 1.14 Z⊙) calibrations. These estimates show excellent agreement with ΔZ ≈ 0.19 and 0.18 dex between the mean values from the two strong-line calibrations for GMOS and MUSE, respectively, consistent with the order of metallicity uncertainty via the strong-line methods. We contend that our findings align with a scenario wherein local Seyferts have undergone seamless gas accretion histories, resulting in positive metallicity profiles over an extended period of time, thereby providing insights into galaxy evolution and the chemical enrichment or depletion of the universe. Additionally, we argue that metal-poor gas inflow from the local interstellar medium and accreted through the circumgalactic medium on to the galaxy systems regulates the star formation processes by diluting their central metallicity and inverting their gas-phase metallicity radial gradients, producing a more prominent anticorrelation between gas-phase metallicity and Eddington ratio.