SIMBAD references

We present results from analysis of spectra from a sample of ∼900 quasars from the Sloan Digital Sky Survey. These objects were selected for their intermediate redshift (1.2<z<1.8), placing Mg II and UV Fe II in the optical bandpass, relatively narrow Mg II lines, and moderately good signal-to-noise ratio spectra. Using a maximum likelihood analysis, we discovered that there is a significant dispersion in the Fe II/Mg II ratios in the sample. Using simulations, we demonstrate that this range and the corresponding correlation between Fe II equivalent width and Fe II/Mg II ratio are primarily a consequence of a larger dispersion of Fe II equivalent width (EW) relative to Mg II EW. This larger dispersion in Fe II EW could be a consequence of a range in iron abundance or a range of Fe II excitation. The latter possibility is supported by evidence that objects with weak (zero) C II] λ2325 equivalent width are likely to have large Fe II/Mg II ratios. We discuss physical effects that could produce a range of Fe II/Mg II ratios.