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arXiv · astro-ph/0701840

Narrow-line AGN in the ISO-2MASS Survey

C. Leipski·M. Haas·H. Meusinger·R. Siebenmorgen·R. Chini·H. Drass·M. Albrecht·B. J. Wilkes·J. P. Huchra·S. Ott·C. Cesarsky·R. Cutri
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Abstract

Context: A long-standing challenge of observational AGN research is to find type 2 quasars, the luminous analogues of Seyfert-2 galaxies. Aims: We search for luminous narrow-line type 2 AGN, characterise their properties, and compare them with broad-line type 1 AGN. Methods: Combining the ISOCAM parallel survey at 6.7 mu with 2MASS, we have selected AGN via near-mid-infrared colours caused by the hot nuclear dust emission. We performed spectroscopy in the optical and, for a subset of the sample, also in the mid-infrared with Spitzer. Results: We find nine type 2 AGN at redshift 0.1 0.5 we did not find type 2 AGN, probably because the hottest dust emission, still covered by the NIR filters, is obscured. The optical spectra of the type 2 host galaxies show young and old stellar populations. Only one object is an ultraluminous infrared galaxy with starburst. The 5-38 mu spectra of the two type 2 sources observed show a strong continuum with PAH emission in one case and silicate absorption in the other case. Conclusions: The near-mid-infrared selection is a successful strategy to find luminous type 2 AGN at low z. The objects exhibit a large range of properties so that it is difficult to infer details by means of popular SED fitting with simple average templates.

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C. Leipski, M. Haas, H. Meusinger, R. Siebenmorgen, R. Chini, H. Drass, M. Albrecht, B. J. Wilkes, J. P. Huchra, S. Ott, C. Cesarsky, R. Cutri. 2007-01-29. Narrow-line AGN in the ISO-2MASS Survey. https://doi.org/10.1051/0004-6361%3A20066168

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