Chemical abundances of Seyfert 2 AGNs – I. Comparing oxygen abundances from distinct methods using SDSS
Abstract
We compare the oxygen abundance (O/H) of the narrow-line regions (NLRs) of Seyfert 2 AGNs obtained through strong-line methods and from direct measurements of the electron temperature (Te-method). The aim of this study is to explore the effects of the use of distinct methods on the range of metallicity and on the mass–metallicity relation of active galactic nuclei (AGNs) at low redshifts (z ≲ 0.4). We used the Sloan Digital Sky Survey (SDSS) and NASA/IPAC Extragalactic Database (NED) to selected optical (3000 < λ(Å) < 7000) emission line intensities of 463 confirmed Seyfert 2 AGNs. The oxygen abundances of the NLRs were estimated using the theoretical Storchi-Bergmann et al. calibrations, the semi-empirical N2O2 calibration, the Bayesian H ii-Chi-mistry code and the Te-method. We found that the oxygen abundance estimations via the strong-line methods differ from each other up to ∼0.8 dex, with the largest discrepancies in the low-metallicity regime ($\rm 12+\log (O/H) \: \lesssim \: 8.5$). We confirmed that the Te-method underestimates the oxygen abundance in NLRs, producing unreal subsolar values. We did not find any correlation between the stellar mass of the host galaxies and the metallicity of their AGNs. This result is independent of the method used to estimate Z.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 17, 2019
- Source ID
- 10.1093/mnras/stz3492
Entities
People
- A C Krabbe
- E B Amôres
- E Pérez-montero
- G F Hägele
- M Armah
- M Faúndez-abans
- Mónica Viviana Cardaci
- O. L. Dors
- P Freitas-lemes
Organizations
- Alfred P. Sloan Foundation
- Case Western Reserve University
- Chinese Academy of Sciences
- Drexel University
- Higher Education Funding Council for England
- Institute for Advanced Study
- Instituto de Astrofísica de Andalucía
- Johns Hopkins University
- Max Planck Society
- National Aeronautics and Space Administration
- National Council for Scientific and Technological Development
- National Science Foundation
- National University of La Plata
- New Mexico State University
- Ohio State University
- Princeton University
- State University of Feira de Santana
- São Paulo Research Foundation
- United States Department of Energy
- United States Naval Observatory
- University do Vale do Paraíba
- University of Basel
- University of Cambridge
- University of Chicago
- University of Pittsburgh
- University of Portsmouth
- University of Washington