Steps toward Determination of the Size and Structure of the Broad‐Line Region in Active Galactic Nuclei. X. Variability of Fairall 9 from Optical Data

Abstract

The results of an optical monitoring campaign on the active nucleus in the luminous Seyfert 1 galaxy Fairall 9 are presented. This campaign was undertaken in parallel with ultraviolet spectroscopic monitoring with the IUE satellite which is described in a separate paper. The primary purpose of this program is to measure the response times (or "" lags ) of the emission lines to continuum variations and thus to extend the range in luminosity of active galactic nuclei (AGNs) for which such measurements have been made. The main conclusions of this work are as follows :