Abstract
In an attempt to understand Fe II emission in quasars, observations of Fe II blends at lambda2100, lambda2500, lambda2950, lambda3200, lambda4570, lambdalambda5190,5320 as well as Mg II lambda2798, the Balmer lines and continuum, and the power law spectral index are reported for 38 quasars and high redshift Seyfert 1 galaxies. Considering only relative strengths among the UV F II blends, which should be insensitive to column density effects, the observed blend strengths agree well with predicted strengths from optically thick collisional excitation models for Fe II emission. However, synthetic spectra based on two extensive Fe II calculations (due to Phillips and to Kwan and Krolik) disagree rather badly with observed spectra. Based on an ad hoc exercise in modifying the predicted multiplet strengths to force a better fit, it is concluded that future correct models of Fe II emission in quasars should include many more terms (low lying doublet terms and terms near 8 eV) than have been included previously, and that electron temperatures higher than 10,000 K should be considered.
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