1995A&A...295..646K

We present near-infrared (JHK) imaging of the Seyfert 2 galaxy NGC 5252, taken with the IRAC2 array on the 2.2m telescope at ESO, La Silla. The unresolved and galactic components to the nuclear emission are separated by a multicomponent fitting of the light profiles in the optical and near-infrared bands. The nuclear flux in a 3" aperture is found to be dominated by the host galaxy with the unresolved component becoming less evident toward shorter wavelengths, suggesting considerable reddening in the nuclear region. The continuum energy distribution from the optical to the radio wavelengths and the near-infrared nonstellar colours confirm a heavily reddened (A_V≥6mag) nonstellar/intrinsic source and the presence of hot dust in the vicinity of the nucleus. On the other hand, the stellar component shows a progressive reddening toward the center, consistent with an optical extinction of A_V∼1mag. The infrared luminosity, computed assuming reradiation by dust of UV/optical nuclear photons, agrees within an order of magnitude with the observed infrared luminosity. The near-infrared data are combined with optical narrow band continuum images to construct colour ratio maps. We find a band of red material in the optical-infrared ratio maps extending ∼3kpc across the nucleus and perpendicular to the biconical ionised structure of NGC 5252. If this infrared band is tracing the distribution of a ring or disk of dust in this galaxy, it may be getting denser in the proximity of the nucleus, significantly contributing to the obscuration of the Seyfert 1 nucleus.