Publication Date:
2014-03-01
Description:
We present a sample of 1317 Infrared-faint radio sources (IFRSs) that, for the first time, are reliably detected in the infrared, generated by cross-correlating the Wide-field Infrared Survey Explorer ( WISE ) all-sky survey with major radio surveys. Our IFRSs are brighter in both radio and infrared than the first-generation IFRSs that were undetected in the infrared by the Spitzer Space Telescope . We present the first spectroscopic redshifts of IFRSs, and find that all but one of the IFRSs with spectroscopy have z 〉 2. We also report the first X-ray counterparts of IFRSs, and present an analysis of radio spectra and polarization, and show that they include gigahertz peaked-spectrum, compact steep-spectrum and ultra-steep-spectrum sources. These results, together with their WISE infrared colours and radio morphologies, imply that our sample of IFRSs represents a population of radio-loud active galactic nuclei at z 〉 2. We conclude that our sample consists of lower redshift counterparts of the extreme first-generation IFRSs, suggesting that the fainter IFRSs are at even higher redshift.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics
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