Chemical abundances of Seyfert 2 AGNs - II. N2 metallicity calibration based on SDSS

We present a semi-empirical calibration between the metallicity (Z) of Seyfert 2 active galactic nuclei and the N2 = log([N HP.6584/11 cy) emission-line intensity ratio. This calibration was derived through the [0 m]..5007/[0 u[),3727 versus N2 diagram containing observational data and photoionizati...

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Detalles Bibliográficos
Autores: Carvalho, S. P., Dors, O. L., Cardaci, M. V., Hägele, Guillermo F., Krabbe, A. C., Pérez Montero, Enrique, Monteiro, A. F., Armah, M., Freitas-Lemes, P.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2020
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/206707
Acceso en línea:http://hdl.handle.net/10261/206707
Access Level:acceso abierto
Palabra clave:Galaxies: abundances
Galaxies: active
Galaxies: evolution
Galaxies: formation
Galaxies: ISM
Galaxies: nuclei
Descripción
Sumario:We present a semi-empirical calibration between the metallicity (Z) of Seyfert 2 active galactic nuclei and the N2 = log([N HP.6584/11 cy) emission-line intensity ratio. This calibration was derived through the [0 m]..5007/[0 u[),3727 versus N2 diagram containing observational data and photoionization model results obtained with the CLOUDY code. The observational sample consists of 463 confirmed Seyfert 2 nuclei (redshift z < 0.4) taken from the Sloan Digital Sky Survey DR7 data set. The obtained Z N2 relation is valid for the range 0.3 r< ( Z/Zo) 2.0 that corresponds to 0.7 < (N2) < 0.6. The effects of varying the ionization parameter (U), electron density and the slope of the spectral energy distribution on the Z estimations are of the order of the uncertainty produced by the error measurements of N2. This result indicates the large reliability of our Z N2 calibration. A relation between U and the IOutj/[OIII line ratio, almost independent of other nebular parameter, was obtained.