C IV and Lyman-alpha emission lines in Seyfert 1 galaxies

Abstract

Good resolution spectra of C IV and Lyman-alpha emission in four Seyfert 1 galaxies (NGC 5548, NGC 4151, NGC 3738, and Fairall 9) are examined, reporting the line profiles and intensity information for this emission. The observations are made with the short wavelength prime camera on the IUE satellite, with a spectral coverage from 1150 A to 2000 A, and a resolution of approximately 2.5 A. Observational data are presented, and it is found that the NGC 5548 C IV line width increased by a factor of 2.5, between December 1979 and November 1980. In the case of Fairall 9, where the Lyman-alpha profile is unaffected by geocoronal emission, C IV and Lyman-alpha profiles are virtually identical. A comparison of line-emitting cloud optical thickness observations will be examined.