Paper detail

The origin of the mid- and far-infrared emission in AGN

The relation between the X-ray emission, the infrared emission and the coronal line emission in a sample of the brightest known Seyfert galaxies is analyzed. A close relationship between the absorption-corrected soft X-ray emission and both the mid-infrared and the coronal line emission is found among the Seyfert type 2 objects studied in this work. Being both the coronal line and the X-ray emissions main tracers of the AGN activity, their relation with the mid-infrared emission adds further support to the claim that the mid-infrared emission is primarily due to dust heated directly by the central AGN. No apparent relationship between the soft X-ray emission and the coronal line and/or the mid-infrared emissions is seen within Seyfert 1 objects, the number of objects of this class in the sample is comparatively smaller though. That discrepancy is partially due to the fact that the soft X-ray emission in the Seyfert 1s is systematically larger by at least one order of magnitude than that in their Seyfert 2 counterparts. Finally, the hard X-ray emission in both Seyfert types shows unrelated to the mid-infrared and coronal line emissions.