Oxygen abundances in the narrow line regions of Seyfert galaxies and the metallicity–luminosity relation

• Autor(a) principal: Armah, Mark
• Data de Publicação: 2023
• Outros Autores: Riffel, Rogério, Dors Júnior, Oli Luiz, Oh, Kyuseok, Koss, Michael, Ricci, Claudio, Trakhtenbrot, Benny, Valerdi, Mabel, Riffel, Rogemar André, Krabbe, Angela Cristina
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/262323
• topic: Galáxias ativas; Evolucao galatica; Formacao de galaxias; Meio interestelar; Galaxias seyfert; Galaxies : abundances; Galaxies : active; Galaxies : evolution; Galaxies : formation; Galaxies : ISM; Galaxies : Seyfert

We present oxygen abundances relative to hydrogen (O/H) in the narrow line regions (NLRs) gas phases of Seyferts 1 (Sy 1s) and Seyferts 2 (Sy 2s) active galactic nuclei (AGNs). We used fluxes of the optical narrow emission line intensities [3 500 < λ(Å) < 7 000] of 561 Seyfert nuclei in the local Universe ( z 0.31) from the second catalogue and data release (DR2) of the BAT AGN Spectroscopic Survey, which focuses on the Swift-BAT hard X-ray ( 10 keV) detected AGNs. We derived O/H from relative intensities of the emission lines via the strong-line methods. We find that the AGN O/H abundances are related to their hosts stellar masses and that they follow a downward redshift evolution. The derived O/H together with the hard X-ray luminosity (LX) were used to study the X-ray luminosity–metallicity (LX–ZNLR) relation for the first time in Seyfert galaxies. In contrast to the broad-line focused (LX–ZBLR) studies, we find that the LX–ZNLR exhibit significant anticorrelations with the Eddington ratio (λEdd) and these correlations vary with redshifts. This result indicates that the low-luminous AGNs are more actively undergoing interstellar medium enrichment through star formation in comparison with the more luminous X-ray sources. Our results suggest that the AGN is somehow driving the galaxy chemical enrichment, as a result of the inflow of pristine gas that is diluting the metal rich gas, together with a recent cessation on the circumnuclear star-formation.