Structural parameters of nearby emission-line galaxies

We present the results of an investigation on the main structural properties derived from VRI and Ha surface photometry of galaxies hosting nuclear emission-line regions [including Seyfert 1, Seyfert 2, low-ionization nuclear emission region (LINER) and starburst galaxies] as compared with normal galaxies. Our original sample comprises 22 active galaxies, four starbursts and one normal galaxy and has been extended with several samples obtained from the literature. Bulge and disc parameters, along with the bulge-to-disc luminosity ratio, have been derived applying an iterative procedure. The resulting parameters have been combined with additional data in order to reach a statistically significant sample. We find some differences in the bulge distribution across the different nuclear types that could imply families of bulges with different physical properties. Bulge and disc characteristic colours have been defined and derived for our sample and compared with a control sample of early-type objects. The results suggest that bulge and disc stellar populations are comparable in normal and active galaxies.