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AGN UNIFICATION AT z ~ 1 : u - R COLORS AND GRADIENTS IN X-RAY AGN HOSTS.
- Source :
- Astrophysical Journal; Oct2011, Vol. 740 Issue 1, Special section p1-16, 16p
- Publication Year :
- 2011
-
Abstract
- We present uncontaminated rest-frame u - R colors of 78 X-ray-selected active galactic nucleus (AGN) hosts at 0.5 < z < i.5 in the Chandra Deep Fields measured with Hubble Space Telescope (HST)/Advanced Camera for Surveys/NICMOS and Very Large Telescope/ISAAC imaging. We also present spatially resolved NUV - R color gradients for a subsample of AGN hosts imaged by HST/Wide Field Camera 3 (WFC3). Integrated, uncorrected photometry is not reliable for comparing the mean properties of soft and hard AGN host galaxies at z ~ 1 due to color contamination from point-source AGN emission. We use a cloning simulation to develop a calibration between concentration and this color contamination and use this to correct host galaxy colors. The mean u - R color of the unobscured/soft hosts beyond ~6 kpc is statistically equivalent to that of the obscured/hard hosts (the soft sources are 0.09 4± 0.16 mag bluer). Furthermore, the rest-frame V - J colors of the obscured and unobscured hosts beyond ~6 kpc are statistically equivalent, suggesting that the two populations have similar distributions of dust extinction. For the WFC3/infrared sample, the mean NUV - R color gradients of unobscured and obscured sources differ by less than ~0.5 mag for r > 1.1 kpc. These three observations imply that AGN obscuration is uncorrelated with the star formation rate beyond ~1 kpc. These observations favor a unification scenario for intermediate-luminosity AGNs in which obscuration is determined geometrically. Scenarios in which the majority of intermediate-luminosity AGNs at z ~ 1 are undergoing rapid, galaxy-wide quenching due to AGN-driven feedback processes are disfavored. [ABSTRACT FROM AUTHOR]
- Subjects :
- GALAXIES
PHOTOMETRY
GALACTIC nuclei
X-rays
ACTIVE galaxies
ACTIVE galactic nuclei
Subjects
Details
- Language :
- English
- ISSN :
- 0004637X
- Volume :
- 740
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Astrophysical Journal
- Publication Type :
- Academic Journal
- Accession number :
- 67507089
- Full Text :
- https://doi.org/10.1088/0004-637X/740/1/3