Observations of optical Fe II emission in the spectra of radio-quiet quasi-stellar objects

The optical spectra of four radio-quiet QSOs have been examined with the Ohio State University image-dissector scanner. In each of these spectra, emission from the optical multiplets of Fe II appears strongly. In contrast, a study by Phillips indicates that Fe II emission is not a general feature of QSOs which are strong radio sources. The similarity between the optical spectra of Seyfert 1 galaxies and radio-quiet QSOs suggests that the latter may simply be more distant examples of the former. The differences between radio sources and radio-quiet objects may be more fundamental than the differences between QSOs and broad-line emission galaxies