Subarcsec emission in Seyfert galaxies: the nuclear component in the L- and M-bands

Abstract

We present deep L- and M- band imaging with ISAAC on the ESO VLT with unprecedented spatial resolution of the nearby Seyfert 2 galaxies NGC 7496 and NGC 7582 and the Seyfert 1 galaxy NGC 7213. The unresolved nuclear component dominates the emission within the central 90 pc region, while the host galaxy accounts for up to 50 % of the integrated emission at both wavelengths within the detected sizes of of 1 kpc in the L-band and 0.5 kpc in the M-band. The overall morphology of the extended component follows the general isophote pattern defined by the near-infrared continuum of the galaxies. However, the central 300 pc regions show much more ordered elliptical isophotes than in the near-infrared. In particular, emission in the L- and M-bands shows well defined central point sources in the two Seyfert 2s.