A CCD STUDY OF THE ENVIRONMENT OF SEYFERT-GALAXIES - I - THE SURVEY

Large-format, R-band CCD data are presented for a spectroscopically co mplete sample of 34 Seyfert galaxies and a control sample of 45 nonact ive galaxies thar are well matched to the Seyfert sample in redshift, luminosity, and morphological type. Gray-scale images of the local env ironment are included for all of the host galaxies, as well as figures showing the surface brightness, ellipticity, and position angle of th e major axis as a function of radius. These data will be used to study the environments of these galaxies and hence to test the ''interactio n hypothesis'' that, over the past two decades, has been implicated as the triggering mechanism for nuclear activity. While there are no dra matic differences in most parameters between the active and nonactive samples, the distributions of ellipticities and major-axis position-an gle excursions of the Seyfert host galaxies and the control galaxies a re marginally different. A higher proportion of Seyfert galaxies appea r to be involved in late-stage mergers. A similar fraction of the cont rol sample, however, displays significant light asymmetries that could be evidence for recent interactions. Moreover, a small but substantia l number of the Seyfert galaxies show no evidence for recent interacti ons as judged by the absence of light asymmetries.