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

Mark Armah*, Rogério Riffel*, O. L. Dors, Kyuseok Oh, Michael J. Koss, Claudio Ricci, Benny Trakhtenbrot, Mabel Valerdi, Rogemar A. Riffel, Angela C. Krabbe

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


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.

Original languageEnglish
Pages (from-to)1687-1703
Number of pages17
JournalMonthly Notices of the Royal Astronomical Society
Issue number2
StatePublished - 1 Apr 2023


  • galaxies: ISM
  • galaxies: Seyfert
  • galaxies: abundances
  • galaxies: active
  • galaxies: evolution
  • galaxies: formation


Dive into the research topics of 'Oxygen abundances in the narrow line regions of Seyfert galaxies and the metallicity-luminosity relation'. Together they form a unique fingerprint.

Cite this