FR II Quasars: Infrared Properties, Star Formation Rates, and Extended Ionized Gas
- Creators
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Fu, Hai
- Stockton, Alan
Abstract
We present Spitzer Infrared Spectrograph spectra and Multiband Imaging Photometer for Spitzer photometry of 12 radio-loud QSOs with FR II morphologies at z ~ 0.3. Six of the sources are surrounded by luminous extended emission-line regions (EELRs), while the other six do not have such extended nebulae. The two subsamples are indistinguishable in their mid-infrared (MIR) spectra and overall IR spectral energy distributions (SEDs). For both subsamples, the MIR aromatic features are undetected in either individual sources or their stacked spectra, and the SEDs are consistent with pure quasar emission without significant star formation. The upper limits to the star formation rate (SFR) are sufficiently low that starburst-driven superwinds can be ruled out as a mechanism for producing the EELRs, which are instead likely the result of the ejection of most of the gas from the system by blast waves accompanying the launching of the radio jets. The FR II quasars deviate systematically from the correlation between host galaxy SFR and black hole accretion rate apparently followed by radio-quiet QSOs, implying little or no bulge growth coeval with the current intensive black hole growth. We also present a new Spitzer estimate of the SFR for the starburst in the host galaxy of the compact steep-spectrum radio quasar 3C 48.
Additional Information
© 2009. The American Astronomical Society. Print publication: Issue 2 (2009 May 10). Received 2009 January 6, accepted for publication 2009 February 24. Published 2009 April 27. H.F. is grateful for the hospitality of the Purple Mountain Observatory, where part of this work was completed. We thank Luis Ho, David Rupke, Jong-Hak Woo, Yanling Wu, and Lin Yan for helpful discussions. We also thank the anonymous referee for helping us to improve the paper and clarify some obscure points. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech and by NSF under grant AST-0807900. 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.Attached Files
Published - Fu2009p2579Astrophys_J.pdf
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Additional details
- Eprint ID
- 15270
- Resolver ID
- CaltechAUTHORS:20090824-114309046
- NASA
- AST-0807900
- NSF
- Created
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2009-08-26Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field