AAS 205th Meeting, 9-13 January 2005
Session 27 Active Galactic Nuclei
Poster, Monday, January 10, 2005, 9:20am-6:30pm, Exhibit Hall

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[27.15] Unveiling a Population of Heavily Obscured AGN with Spitzer and the VLA

J. L. Donley, G. H. Rieke, J. R. Rigby, P. G. Perez-Gonzalez (Univ. of Arizona)

We have searched for heavily obscured AGN in the Hubble Deep Field North. Radio-intermediate and radio-loud AGN are significantly brighter in the radio (with respect to the mid-infrared) than are star-forming galaxies and radio-quiet AGN, which fit the radio-infrared correlation. We have used this correlation, along with 24 micron and 20 cm data from the Spitzer Space Telescope and the VLA, to identify a sample of AGN candidates independently of their X-ray properties. We find a significant sample of radio-intermediate AGN candidates that are not X-ray detected, even in regions with X-ray exposures in excess of 1 Ms. The relationship between the radio compactness and the ratio of radio to X-ray flux suggests that AGN that are faint or missed in the X-ray are viewed edge-on and are heavily obscured. X-ray background models predict that such objects should be common in the deep survey fields. Identifying heavily obscured AGN missed in the X-ray and later quantifying their number is necessary if we are to understand the accretion history of the Universe.

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Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.