Identifying AGNs from X-ray detections$-$II: Metallicity calibrations for the ${\mathrm{N}}_2{\mathrm{O}}_2$ and ${\mathrm{N}}_2{\mathrm{S}}_2$ 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…