24 citations · 48 across the 10 of their papers we have counts for
10 papers · 1 filter
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…
Metallicity of Active Galactic Nuclei from ultraviolet and optical emission lines I: Carbon abundance dependence
O. L. Dors, C. B. Oliveira, M. V. Cardaci +9
Metallicity () estimates based on ultraviolet (UV) emission lines from the narrow-line regions (NLRs) of active galactic nuclei (AGNs) have been found to differ from those deriv…
Semi-empirical calibration of the oxygen abundance for LINER galaxies based on SDSS-IV MaNGA -- The case for strong and weak AGN
C. B. Oliveira, O. L. Dors, I. A. Zinchenko +5
In this paper, we present a semi-empirical calibration between the oxygen abundance and the emission-line ratio for Low Ionization Nuclear Emission Regions (LINERs). This rela…
Empirical calibration for helium abundance determinations in Active Galactic Nuclei
O. L. Dors, G. C. Almeida, C. B. Oliveira +10
For the first time, a calibration between the HeI /H emission line ratio and the helium abundance =12+log(He/H) for Narrow line regions (NLRs) of Seyfert~2 Activ…
Direct estimates of nitrogen abundance for Seyfert 2 nuclei
O. L. Dors, M. V. Cardaci, G. F. Hägele +10
We derive the nitrogen and oxygen abundances in the Narrow Line Regions (NLRs) of a sample of 38 local () Seyfert~2 nuclei. For that, we consider narrow optical emis…
Chemical abundances of LINER galaxies -- Nitrogen abundance estimations
C. B. Oliveira, A. C. Krabbe, O. L. Dors +5
In this work, we investigated the nitrogen and oxygen abundances in a sample of galaxies with Low Ionization Nuclear Emission Regions (LINERs) in their nucleus. Optical spectroscop…
Diagnostic diagrams for ram-pressure stripped candidates
A. C. Krabbe, J. A. Hernandez-Jimenez, C. Mendes de Oliveira +7
This paper presents a method for finding ram-pressure stripped (RPS) galaxy candidates by performing a morphological analysis of galaxy images obtained from the Legacy survey. We c…
Cosmic metallicity evolution of Active Galactic Nuclei: Implications for optical diagnostic diagrams
Oli L. Dors, M. V. Cardaci, G. F. Hagele +5
We analyze the validity of optical diagnostic diagrams relying on emission-lines ratios and in the context of classifying Active Galactic Nuclei (AGNs) according to the cosmic meta…
Chemical abundance of LINER galaxies -- Metallicity calibrations based on SDSS-IV MaNGA
C. B. Oliveira, A. C. Krabbe, J. A. Hernandez-Jimenez +5
The ionizing source of Low Ionization Nuclear Emission Regions (LINERs) is uncertain. Because of this, an empirical relation to determine the chemical abundances of these objects h…
Chemical abundances in Seyfert galaxies -IX. Helium abundance estimates
O. L. Dors, M. Valerdi, P. Freitas-Lemes +7
For the first time, the helium abundance relative to hydrogen (He/H), which relied on direct measurements of the electron temperature, has been derived in the narrow line regions (…