NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2018-12-13 T09:27:43 PST
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For refcode 2007ApJ...660..167D:
Retrieve 65 NED objects in this reference.
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NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
2007ApJ...660..167D Spitzer Power-Law Active Galactic Nucleus Candidates in the Chandra Deep Field -- North J. L. Donley, G. H. Rieke, P. G. Perez-Gonzalez, J. R. Rigby, and A. Alonso-Herrero Abstract. We define a sample of 62 galaxies in the Chandra Deep Field -- North whose Spitzer IRAC SEDs exhibit the characteristic power-law emission expected of luminous AGNs. We study the multiwavelength properties of this sample and compare the AGNs selected in this way to those selected via other Spitzer color-color criteria. Only 55% of the power-law galaxies are detected in the X-ray catalog at exposures of >0.5 Ms, although a search for faint emission results in the detection of 85% of the power-law galaxies at the >= 2.5 {sigma} detection level. Most of the remaining galaxies are likely to host AGNs that are heavily obscured in the X-ray. Because the power-law selection requires the AGNs to be energetically dominant in the near- and mid-infrared, the power-law galaxies comprise a significant fraction of the Spitzer-detected AGN population at high luminosities and redshifts. The high 24 micron detection fraction also points to a luminous population. The power-law galaxies comprise a subset of color-selected AGN candidates. A comparison with various mid-infrared color selection criteria demonstrates that while the color-selected samples contain a larger fraction of the X-ray -- luminous AGNs, there is evidence that these selection techniques also suffer from a higher degree of contamination by star-forming galaxies in the deepest exposures. Considering only those power-law galaxies detected in the X-ray catalog, we derive an obscured fraction of 68% (2 : 1). Including all of the power-law galaxies suggests an obscured fraction of <81% (4 : 1).
Retrieve 65 NED objects in this reference.
Please click here for ADS abstract

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