Violet absorption edges of C IV lines in Wolf-Rayet spectra: possible superposition with diffuse interstellar bands at 5780 Å and 5797 Å

Abstract

It is shown that the violet edges normally seen in Wolf-Rayet stars around 5800Å are principally due to displaced C IV absorption. The diffuse interstellar bands are seldom of comparable strength and can be seen separately if the absorption characteristics of the envelope of the Wolf-Rayet stars are such as to avoid an overlap between the two.