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Magellan Spectroscopy of AGN Candidates in the COSMOS Field

Trump, Jonathan R. and Impey, Chris D. and McCarthy, Patrick J. and Elvis, Martin and Huchra, John P. and Brusa, Marcella and Hasinger, Günther and Schinnerer, Eva and Capak, Peter and Lilly, Simon J. and Scoville, Nick Z. (2007) Magellan Spectroscopy of AGN Candidates in the COSMOS Field. Astrophysical Journal Supplement Series, 172 (1). pp. 383-395. ISSN 0067-0049. doi:10.1086/516578.

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We present spectroscopic redshifts for the first 466 X-ray- and radio-selected AGN targets in the 2 deg^2 COSMOS field. Spectra were obtained with the IMACS instrument on the Magellan (Baade) telescope, using the nod-and-shuffle technique. We identify a variety of type 1 and type 2 AGNs, as well as red galaxies with no emission lines. Our redshift yield is 72% down to i_(AB) = 24, although the yield is >90% for i_(AB) < 22. We expect the completeness to increase as the survey continues. When our survey is complete and additional redshifts from the zCOSMOS project are included, we anticipate ~1100 AGNs with redshifts over the entire COSMOS field. Our redshift survey is consistent with an obscured AGN population that peaks at z ~ 0.7, although further work is necessary to disentangle the selection effects.

Item Type:Article
Related URLs:
URLURL TypeDescription
Brusa, Marcella0000-0002-5059-6848
Hasinger, Günther0000-0002-0797-0646
Schinnerer, Eva0000-0002-3933-7677
Capak, Peter0000-0003-3578-6843
Lilly, Simon J.0000-0002-6423-3597
Scoville, Nick Z.0000-0002-0438-3323
Additional Information:© 2009 American Astronomical Society. Print publication: Issue 1 (2007 September); received 2006 April 24; accepted for publication 2006 May 26. We would like to thank Alan Dressler and the IMACS team for creating an excellent instrument, as well as telescope operators Hernan Nuñez and Felipe Sanchez and the Las Campanas Observatory staff for support while observing. We thank Mike Westover for help with the January observations.We also thank the COSMOS team for their work in creating the catalogs used for selecting our targets. The HST COSMOS Treasury program was supported through NASA grant HST-GO-09822.
Group:COSMOS, Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Subject Keywords:galaxies: active; quasars: general; surveys
Issue or Number:1
Record Number:CaltechAUTHORS:20091202-100349927
Persistent URL:
Official Citation:Magellan Spectroscopy of AGN Candidates in the COSMOS Field Jonathan R. Trump, Chris D. Impey, Patrick J. McCarthy, Martin Elvis, John P. Huchra, Marcella Brusa, Gunther Hasinger, Eva Schinnerer, Peter Capak, Simon J. Lilly, and Nick Z. Scoville 2007 ApJS 172 383-395 doi: 10.1086/516578
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:16855
Deposited On:04 Dec 2009 18:25
Last Modified:08 Nov 2021 23:30

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