Please use this identifier to cite or link to this item:
Title: First results from the Australia telescope compact array 18-GHz pilot survey
Authors: Ricci, Roberto
Sadler, Elaine M.
Ekers, R.D.
Staveley-Smith, Lister
Wilson, W.E.
Kesteven, Michael J.
Subrahmanyan, Ravi
Keywords: Galaxies: active
Cosmic microwave background
Radio continuum
Issue Date: Oct-2004
Publisher: Blackwell Publishing for the Royal Astronomical Society
Citation: Monthly Notices of the Royal Astronomical Society, 2004, Vol.354, p305-320.
Abstract: As a pilot study for the first all-sky radio survey at short wavelengths, we have observed 1216 deg2 of the southern sky at 18 GHz (16 mm) using a novel wide-band (3.4-GHz bandwidth) analogue correlator on one baseline of the Australia Telescope Compact Array. We scanned a region of sky between declination -71° and -59° with an rms noise level of 15 mJy. Follow-up radio imaging of candidate sources above a 4σ detection limit of 60 mJy resulted in 221 confirmed detections, for which we have measured accurate positions and flux densities. For extragalactic sources, the survey is roughly 70 per cent complete at a flux density of 126 mJy and 95 per cent complete above 300 mJy. Almost half the detected sources lie within a few degrees of the Galactic plane, but there are 123 sources with |b| > 5°, which can be assumed to be extragalactic. The differential source counts for extragalactic sources in the range 0.1 Jy <=S18GHz<= 3 Jy are well fitted by a relation of the form n(S) = 57 (S/Jy)-2.2+/-0.2 Jy-1 sr-1, in good agreement with the 15-GHz counts published by Taylor et al. and Waldram et al. Over 70 per cent of the extragalactic sources have a flat radio spectrum (α180.843 > -0.5, Sν~να), and 29 per cent have inverted radio spectra (α180.843 > 0). The optical identification rate is high: 51 per cent of the extragalactic sources are identified with stellar objects (candidate quasi-stellar objects), 22 per cent with galaxies and only 27 per cent with faint optical objects or blank fields.
Description: Restricted Access.
ISSN: 0035-8711
1365-2966 (Online)
Alternative Location:
Copyright: 2004 Royal Astronomical Society
Appears in Collections:Research Papers (A&A)

Files in This Item:
File Description SizeFormat 
  Restricted Access
Restricted Access1.23 MBAdobe PDFView/Open Request a copy

Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.