Morphology and Luminosity Distribution of Seyfert Galaxies

Extract

V and I CCD images for 13 Seyfert galaxies have been obtained at the Cassegrain focus of the JKT at the Roque de los Muchachos Observatory, Canary Islands. Integrated V and I magnitudes were obtained sampling the intensity of each galaxy in a circular area, up to a radial distance R at which the V surface brightness is 24 mag/sq arcsec. Mean luminosities M_V = −21.89 and M_I = −22.92 have been calculated adopting the galaxian radial velocities given by Adams (1977) and H_o = 55 kms⁻¹ Mpc⁻¹. By using elliptically averaged V and I luminosity profiles and the most outstanding morphological features from isophote maps we can distinguish two groups: 1) Galaxies with prominent bulge (Mk 50, Mk 124, Mk 348 and 3C227) where almost the entire profile is fitted by an r^−1/4 law and no evidence for an exponential disk is found; some have a very diffuse external structure, like Mk 50 and Mk 348; and 2) Spiral galaxies (Mk 9, Mk 10, Mk 79, Mk 110, Mk 352, Mk 358 and Mk 618) showing spiral arms and exponential disks; most of them have also a prominent bar. Mk 42, whose luminosity profiles are strongly disturbed by a bright external ring, and NGC 985 a galaxy with a single arm, were both included in this group.