60 citations · 274 across the 13 of their papers we have counts for
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Identifying AGNs from X-ray detectionsII: Metallicity calibrations for the and diagnostics
Mark Armah, O. L. Dors, Rogério Riffel +4
Emission-line ratios from ions with nearly identical ionization potentials offer a robust solution to the degeneracies inherent to traditional active galactic nuclei (AGNs) metalli…
Identifying AGNs from X-ray detections-I: Metallicity calibrations in AGNs with X-ray luminosity as the primary input parameter
Mark Armah, O. L. Dors, Rogério Riffel +4
We present the first semi-empirical strong-line calibrations to determine metallicity in Active Galactic Nuclei (AGNs) that use the directly observable X-ray luminosity (Lx) instea…
Metallicity of Active Galactic Nuclei from ultraviolet and optical emission lines-II. Revisiting the metallicity calibration and its implications
O. L. Dors, C. B. Oliveira, M. V. Cardaci +7
In this study, a new semi-empirical calibration is proposed between ultraviolet emission lines (\ion{C}{iii}], \ion{C}{iv}, \ion{He}{ii}]) of…
Spatially-resolved gas-phase metallicity in Seyfert galaxies
Mark Armah, Rogério Riffel, L. G. Dahmer-Hahn +7
We explore the relations between the gas-phase metallicity radial profiles (few hundred inner parsec) and multiple galaxy properties for 15 Seyfert galaxies from the AGNIFS (Active…
Chemical abundances in Seyfert galaxies X. Sulphur abundance estimates
O. L. Dors, M. Valerdi, R. A. Riffel +12
For the first time, the sulphur abundance relative to hydrogen (S/H) in the Narrow Line Regions of a sample of Seyfert 2 nuclei (Sy 2s) has been derived via direct estimation of th…
Oxygen abundances in the narrow line regions of Seyfert galaxies and the metallicity-luminosity relation
Mark Armah, Rogério Riffel, O. L. Dors +7
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…