SURFACE BRIGHTNESS DISTRIBUTIONS OF 4 SEYFERT-GALAXIES BASED ON MULTIAPERTURE UBV PHOTOMETRY

An analysis of surface brightness distributions for the four Seyfert g alaxies NCC 3515, NGC 4151, NGC 5548, and NGC 7469 based on multi-aper ture UBV photometry is presented. Both new photometric data and data f rom the literature are used. The traditional method for decomposing th e surface brightness distribution into components gives very large sca tters in the estimates for the bulge and disk parameters. The surface brightness distributions are modeled using functions of the form mu(r) = a + br + cr(1/n), where n = 2 or 4. The resulting models are used t o calculate the galaxy brightnesses in different apertures taking into account a ''boundary'' condition: the calculated brightness in a give n aperture must not exceed the minimum total brightness for the variab le source and surrounding galaxy observed in this aperture. The models with n = 2 satisfy this ''boundary'' condition better, while models w ith n = 4 yield galaxy brightnesses that are too high. The observed va riety and behavior of the color indices near the centers of the galaxi es are associated with specific features in each of the galaxies, and provide evidence for the presence of star formation.