RT Journal Article
T1 Spitzer power-law active galactic nucleus candidates in the chandra deep field-north
A1 Donley, J. L.
A1 Rieke, G. H.
A1 Pérez González, Pablo Guillermo
A1 Rigby, J. R.
A1 Alonso Herrero, A.
AB 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 σ 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 μm 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).
PB American Astronomical Society
SN 0004-637X
YR 2007
FD 2007-05-01
LK https://hdl.handle.net/20.500.14352/51940
UL https://hdl.handle.net/20.500.14352/51940
LA eng
NO © 2007 The American Astronomical Society. All rights reserved. This work was supported by an NSF Graduate Research Fellowship and by NASA through contract 1255094 issued by JPL/California Institute of Technology. We thank the referee for helpful comments that improved the paper.
NO National Science Foundation (NSF)
NO National Aeronautics and Space Administration (NASA)
NO JPL/California Institute of Technology
DS Docta Complutense
RD 26 mar 2026