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Radio Observations of the Hubble Deep Field-South Region. IV. Optical Properties of the Faint Radio Population

Huynh, Minh T. and Jackson, Carole A. and Norris, Ray P. and Fernandez-Soto, Alberto (2008) Radio Observations of the Hubble Deep Field-South Region. IV. Optical Properties of the Faint Radio Population. Astronomical Journal, 135 (6). pp. 2470-2495. ISSN 0004-6256.

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The Australia Telescope Hubble Deep Field-South (ATHDF-S) survey of the Hubble Deep Field-South (HDF-S) reaches sensitivities of ~10 μJy at 1.4, 2.5, 5.2, and 8.7 GHz, making the ATHDF-S one of the deepest surveys ever performed with the Australia Telescope Compact Array (ATCA). Here, we present the optical identifications of the ATHDF-S radio sources using data from the literature. We find that ~66% of the radio sources have optical counterparts to I = 23.5 mag. Deep Hubble Space Telescope (HST) imaging of the area identifies a further 12% of radio sources. We present new spectroscopic observations for 98 of the radio sources and supplement these spectroscopic redshifts with photometric ones calculated from five-band optical imaging. The host galaxy colors and radio-to-optical ratios indicate that low-luminosity (or "radio-quiet") active galactic nuclei make up a significant proportion of the sub-mJy radio population, a result which is in accordance with a number of other deep radio studies. The radio-to-optical ratios of the bright (S 1.4 GHz > 1 mJy) sources are consistent with a bimodal distribution.

Item Type:Article
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Norris, Ray P.0000-0002-4597-1906
Additional Information:© 2008 The American Astronomical Society. Received 2007 October 19, accepted for publication 2008 March 21. Published 2008 May 15. M.T.H. would like to thank Nick Seymour for useful discussions. A.F.S. acknowledges support from MEC Project AYA2006-14056 and a "Ramón y Cajal" research contract. The Australia Telescope Compact Array is part of the Australia Telescope, which is funded by the Commonwealth of Australia for operation as a National Facility managed by the CSIRO. Online-only material: color figures, machine-readable tables
Funding AgencyGrant Number
MEC ProjectAYA2006-14056
“Ramón y Cajal” research contractUNSPECIFIED
Subject Keywords:radio continuum: galaxies – surveys
Issue or Number:6
Record Number:CaltechAUTHORS:HUYaj08
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:11716
Deposited By: Archive Administrator
Deposited On:21 Sep 2008 05:53
Last Modified:09 Mar 2020 13:19

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