Morphology and kinematics of spiral galaxies with and without AGNs

Abstract

The analysis of a sample of 30 isolated spiral galaxies with andwithout an Active Galactic Nucleus (AGN) results in active and control galaxies having similarbulge and disk properties. Secondary bars also seem to beindistinguishable. Circumnuclear kinematics are also analyzed todisentangle what kind of mechanisms are taking place in thecircumnuclear regions. From long slit spectra of a subsample ofisolated active and non-active spiral galaxies in the Hαemission line region, the shape and properties of the rotation curvesare obtained together with the line ratios used to estimate themetallicity of all the detected HII regions. Kinematics andmetallicities are also studied in comparison with the propertiesdetermined for a family of 111 spiral galaxies with a welldetermined environmental status, ranging from isolation to close, though not disruptive, interaction with satellites or companions. Thestellar kinematics are also studied in some cases, with as mainresult the detection of a stellar velocity dispersion drop in thecenters of four Seyfert galaxies. Together with previous findings, ourresults from the comparison between active and non-active isolatedgalaxies point to AGNs being an episode in the life of galaxies,provided that the fuel is available and the accumulation mechanismsare at work.