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The Extraordinary Mid-infrared Spectral Properties of FeLoBAL Quasars

Farrah, D. and Urrutia, T. and Lacy, M. and Lebouteiller, V. and Spoon, H. W. W. and Bernard-Salas, J. and Connolly, N. and Afonso, J. and Connolly, B. and Houck, J. (2010) The Extraordinary Mid-infrared Spectral Properties of FeLoBAL Quasars. Astrophysical Journal, 717 (2). pp. 868-877. ISSN 0004-637X.

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We present mid-infrared (mid-IR) spectra of six FeLoBAL quasi-stellar objects (QSOs) at 1 < z < 1.8, taken with the Spitzer Space Telescope. The spectra span a range of shapes, from hot dust-dominated active galactic nuclei (AGNs) with silicate emission at 9.7 μm to moderately obscured starbursts with strong polycyclic aromatic hydrocarbon (PAH) emission. The spectrum of one object, SDSS 1214–0001, shows the most prominent PAHs yet seen in any QSO at any redshift, implying that the starburst dominates the mid-IR emission with an associated star formation rate on the order of 2700 M_⊙ yr^(–1). With the caveats that our sample is small and not robustly selected, we combine our mid-IR spectral diagnostics with previous observations to propose that FeLoBAL QSOs are at least largely comprised of systems in which (1) a merger-driven starburst is ending, (2) a luminous AGN is in the last stages of burning through its surrounding dust, and (3) we may be viewing over a restricted line-of-sight range.

Item Type:Article
Related URLs:
URLURL TypeDescription DOIArticle
Farrah, D.0000-0003-1748-2010
Urrutia, T.0000-0001-6746-9936
Lacy, M.0000-0002-3032-1783
Spoon, H. W. W.0000-0002-8712-369X
Bernard-Salas, J.0000-0002-8452-8675
Afonso, J.0000-0002-9149-2973
Additional Information:Copyright is not claimed for this article. Received 2009 December 14; accepted 2010 May 15; published 2010 June 18. We thank the referee for a helpful report. 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. This research has made extensive use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. D.F. thanks STFC for support via an Advanced Fellowship. N.C. gratefully acknowledges support from a Cottrell College Science Award from the Research Corporation and from an NSF RUI grant.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Cottrell Scholar of Research CorporationUNSPECIFIED
Science and Technology Facilities Council (STFC)UNSPECIFIED
Subject Keywords:galaxies: active; galaxies: evolution; infrared: galaxies; quasars: absorption lines
Issue or Number:2
Classification Code:PACS: 98.54.Ep; 98.54.Aj; 98.54.Cm; 98.58.Bz; 95.85.Hp; 98.62.Qz
Record Number:CaltechAUTHORS:20100824-095756503
Persistent URL:
Official Citation:D. Farrah et al 2010 ApJ 717 868 doi: 10.1088/0004-637X/717/2/868
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:19625
Deposited By: Tony Diaz
Deposited On:30 Aug 2010 02:15
Last Modified:04 Nov 2019 02:09

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