Chemical abundances in Seyfert galaxies–VIII. Argon abundance estimates
AF Monteiro, OL Dors - Monthly Notices of the Royal …, 2021 - academic.oup.com
Monthly Notices of the Royal Astronomical Society, 2021•academic.oup.com
For the first time, the argon abundance relative to hydrogen abundance (Ar/H) in the narrow
line region of a sample of Seyfert 2 nuclei has been derived. In view of this, optical narrow
emission line intensities of a sample of 64 local Seyfert 2 nuclei (z< 0.25) taken from Sloan
Digital Sky Survey DR7 and measured by the MPA/JHU group were considered. We
adopted the T e-method for AGNs, which is based on direct determination of the electron
temperature, together with a grid of photoionization model results, built with the cloudy code …
line region of a sample of Seyfert 2 nuclei has been derived. In view of this, optical narrow
emission line intensities of a sample of 64 local Seyfert 2 nuclei (z< 0.25) taken from Sloan
Digital Sky Survey DR7 and measured by the MPA/JHU group were considered. We
adopted the T e-method for AGNs, which is based on direct determination of the electron
temperature, together with a grid of photoionization model results, built with the cloudy code …
Abstract
For the first time, the argon abundance relative to hydrogen abundance (Ar/H) in the narrow line region of a sample of Seyfert 2 nuclei has been derived. In view of this, optical narrow emission line intensities of a sample of 64 local Seyfert 2 nuclei (z < 0.25) taken from Sloan Digital Sky Survey DR7 and measured by the MPA/JHU group were considered. We adopted the Te-method for AGNs, which is based on direct determination of the electron temperature, together with a grid of photoionization model results, built with the cloudy code, to obtain a method for the derivation of the Ar/H abundance. We find that for a metallicity range of , Seyfert 2 nuclei present Ar/H abundance ranging from ∼0.1 to ∼3 times the argon solar value, adopting and . These range of values correspond to and , respectively. The range of Ar/H and Ar/O abundance values obtained from our sample are in consonance with estimations from extrapolations of the radial abundance gradients to the central parts of the disc for four spiral galaxies. We combined our abundance results with estimates obtained from a sample of H ii galaxies, which were taken from the literature, and found that the Ar/O abundance ratio decreases slightly as the O/H abundance increases.
Oxford University Press