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Far‐Infrared Observations of Radio Quasars and FR II Radio Galaxies

Shi, Y. and Rieke, G. H. and Hines, D. C. and Neugebauer, G. and Blaylock, M. and Rigby, J. and Egami, E. and Gordon, K. D. and Alonso-Herrero, A. (2005) Far‐Infrared Observations of Radio Quasars and FR II Radio Galaxies. Astrophysical Journal, 629 (1). pp. 88-99. ISSN 0004-637X. doi:10.1086/431344.

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We report MIPS photometry of 20 radio-loud quasars and galaxies at 24 and 70 μm (and of five at 160 μm). We combine this sample with additional sources detected in the far-infrared by IRAS and ISO for a total of 47 objects, including 23 steep-spectrum type I AGNs: radio-loud quasars and broad-line radio galaxies; and 24 type II AGNs: narrow-line and weak-line FR II radio galaxies. Of this sample, the far-infrared emission of all but 3C 380 appears to be dominated by emission by dust heated by the AGN and by star formation. The AGN appears to contribute more than 50% of the far-infrared luminosity in most of the sources. It is also expected that the material around the nucleus is optically thin in the far-infrared. Thus, the measurements at these wavelengths can be used to test the orientation-dependent unification model. As predicted by the model, the behavior of the sources is consistent with the presence of an obscuring circumnuclear torus; in fact, we find that it may still have significant optical depth at 24 μm. In addition, as expected for the radio-loud quasars, there is a significant correlation between the low-frequency radio (178 MHz) and the 70 μm emission, two presumably isotropic indicators of nuclear activity. This result is consistent with the simple unified scheme. However, there is a population of radio galaxies that are underluminous at 70 μm compared with the radio-loud quasars and hence are a challenge to the simple unified model.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Rieke, G. H.0000-0003-2303-6519
Hines, D. C.0000-0003-4653-6161
Rigby, J.0000-0002-7627-6551
Alonso-Herrero, A.0000-0001-6794-2519
Additional Information:© 2005 American Astronomical Society. Received 2005 January 12 Accepted 2005 April 26 We thank John Moustakas for helpful discussions and the anonymous referee for detailed comments. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This work was supported by NASA through contract No. 960785 issued by JPL/Caltech.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Subject Keywords:galaxies: active; infrared: galaxies; quasars: general
Issue or Number:1
Record Number:CaltechAUTHORS:20170511-140518033
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Official Citation:Y. Shi et al 2005 ApJ 629 88
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:77377
Deposited By: Ruth Sustaita
Deposited On:12 May 2017 18:57
Last Modified:15 Nov 2021 17:30

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