The composite UV emission spectrum of Seyfert 1 galaxies.

Abstract

A composite spectrum is built in the wavelength range λλ1200-3000 Å, from IUE spectra of 27 Seyfert 1 nuclei. Comparisons with spectra of quasars show that all emission features seen in quasars, including the Fe II UV multiplets, are also observed in the much less luminous Seyfert 1 nuclei. This is taken as a confirmation that Seyfert 1 nuclei are low luminosity radio quiet or flat radio spectrum quasars. The C IV λ1550 equivalent width does not exceed ≡110 Å in the faintest Seyfert 1 nuclei; this is much less than the extrapolation of the suggested correlation between C IV EW and intrinsic luminosity would predict.