Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. XIV. Intensive optical spectrophotometric observations of NGC 7469

We present results of an intensive 2 month campaign of ground-based spectrophotometric monitoring of the Seyfert 1 galaxy NGC 7469, with a temporal resolution less than or similar to 1 day. The broad Ha and HE emission lines respond to similar to 35% ultraviolet continuum variations with an amplitude of similar to 10% and time delays of 5.6 +/- 1.3 days and 5.4 +/- 0.8 days, respectively. We interpret this as evidence of variable Balmer line gas similar to 5-6 light days from the central source in this object, widely believed to be a supermassive black hole. The virial mass of the central source implied by line widths and time delays is similar to 10(6)-10(7) M-.. Concomitantly, we find evidence for wavelength-dependent continuum time delays: optical continuum variations lag those at 1315 Angstrom by 1.0 +/- 0.3 days at 4865 Angstrom to 1.5 +/- 0.7 days at 6962 Angstrom. This suggests a stratified continuum reprocessing region extending several light days from the central source, possibly an accretion disk.