Near IR spectroscopy of active galactic nuclei^*

¹ LUTH, FRE 2462 du CNRS, associé à l'Université Denis Diderot, Observatoire de Paris, Section de Meudon, 92195 Meudon Cedex, France
² European Southern Observatory, Santiago, Chile
³ X-ray Astronomy Group, Department of Physics and Astronomy, University of Leicester, Leicester LEI 7RH

Corresponding author: C. Boisson, catherine.boisson@obspm.fr

Received: 23 November 2001
Accepted: 30 September 2002

Abstract

Using the VLT together with the near infrared instrument ISAAC, we have obtained medium spectral and high spatial resolution observations of a sample of nearby Seyfert galaxies in the H-band. This band is particularly suited for stellar population studies since the stellar component dominates over the AGN nucleus. The H-band also includes the peak contribution from cool stars. The AGN spectra are very rich in strong metallic lines which are sensitive to stellar luminosity class. For 4 out of 5 galaxies the central velocity dispersions are found to be significantly lower than reported in previous studies. Gradients in the stellar population within the central regions were searched for, together with evidence for dilution of the stellar spectral features within the nucleus.