Abstract
We present a new diagnostic diagram based on ISOCAMspectra (5-16 μm) to distinguish the emission inducedby the active galactic nucleus (AGN) from that associated with thestar formation activity. This diagnostic based on the mid-IRcontinuum and the Unidentified Infrared Band (UIB) intensity allowsus to estimate the relative importance of the three components (HIIregions, diffuse/photo-dissociation regions (PDRs), and AGN) contained ingalaxy mid-infrared emission. In AGN spectra, we confirm the absenceof UIBs presumably photodissociated by the X-UV radiation field. Inaddition, a non-negligible continuum below 9 μm commonlyassociated with emission from hot dust is present in AGNs. Adiagnostic diagram derived from these two results can be used fordetecting obscured AGNs embedded in a large concentration of dust.
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Laurent, O., Mirabel, I., Gallais, P. et al. The AGNS and their host galaxies as seen in the mid-infrared. Astrophysics and Space Science 266, 175–180 (1999). https://doi.org/10.1023/A:1002670203094
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DOI: https://doi.org/10.1023/A:1002670203094