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Spatial resolution bias in the mid-infrared Starburst/AGN classification

O. Laurent·I. F. Mirabel·V. Charmandaris·P. Gallais·M. Sauvage·L. Vigroux·C. Cesarsky
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Abstract

We present the effects of limited spatial resolution to the observed mid-infrared (MIR) spectrum of an active galactic nucleus (AGN) surrounded by a disk with massive star forming regions. Using MIR observations of the face-on nearby Seyfert 1 galaxy NGC 6814, we vary the observing aperture and examine the evolution of the observed AGN/starburst fraction with our MIR diagnostic. We show that the spatial resolution of ISOCAM is sufficient to disentangle AGN from starburst features in nuclear regions of nearby galaxies (D<50Mpc). However, with the exception of a few ultra-luminous galaxies, dilution effects hide completely the AGN contribution in more distant galaxies.

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O. Laurent, I. F. Mirabel, V. Charmandaris, P. Gallais, M. Sauvage, L. Vigroux, C. Cesarsky. 2000-05-18. Spatial resolution bias in the mid-infrared Starburst/AGN classification. https://arxiv.org/abs/astro-ph/0005377

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