Fe II emission spectra in AGN: observations and theoretical interpretation
The enrichment of Fe, relative to alpha elements such as O and Mg, represents a potential means to measure the ages of quasi-stellar object (QSO) host galaxies and probe nucleosynthesis in the early universe. QSOs exhibit prominent Fe II features and Mg II 2800 angstrom resonance doublet emission in the ultraviolet. Although chemical evolutionary models predict that the Fe/Mg abundance ratio decre