VLT on-axis spectroscopy of quasar host galaxies

We present the full analysis of our sample of 20 bright low redshift quasars (M-B < -23 and z < 0.35), observed spectroscopically with the VLT FORS1, with objectives of characterizing the hosts and trying to understand how quasars are fueled or triggered. Applying the MCS deconvolution method, we are able to separate the galactic light from the quasar light, enabling i.e. global analysis of the gaseous and stellar content and gaseous dynamics. We find that 45% of the sample show signs of interaction, while half of the quasars are hosted in spiral galaxies, even when brighter than M-V = -23.5. We also find many galaxies containing gas ionized by the quasar radiation far from the nucleus, all of these showing interaction or merger signs. We find spectroscopic evidences that such interactions bring gas in the broad and narrow line regions and power the nucleus. (c) 2006 Elsevier B.V. All rights reserved.