Evidence for an Accelerating Wind as the Broad-Line Region in NGC 3516

Spectroscopic data in wavelengths 900-3000 Å have been obtained in a low flux state of the nucleus of the Seyfert 1 galaxy NGC 3516. The line profiles show P Cygni characteristics, particularly in O VI λ1032, and are compared with data from an earlier and higher state. The profiles are suggestive of and consistent with an accelerating wind driven by a disk continuum source in which the ionization radii have changed. This scenario may apply to the formation of other broad emission lines in active galactic nuclei.