First results from the ATCA 18 GHz pilot survey

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

17 pages, 12 figures, 5 tables, accepted by MNRAS, external tables and radio-optical overlays in appendix A can be found at

Scientific paper

As a pilot study for the first all-sky radio survey at short wavelengths, we have observed 1216 sq. deg. of the southern sky at 18GHz (16mm) using a novel wide-band (3.4GHz bandwidth) analogue correlator on one baseline of the Australia Telescope Compact Array (ATCA). We scanned a region of sky between declination -71 and -59 degrees with an rms noise level of 15mJy. Follow-up radio imaging of candidate sources above a 4 sigma detection limit of 60mJy resulted in 221 confirmed detections, for which we have measured accurate positions and flux densities. For extragalactic sources, the survey is roughly 70% complete at a flux density of 126mJy and 95% complete above 300mJy. Almost half the detected sources lie within a few degrees of the Galactic plane, but there are 123 sources with |b|>5 degrees which can be assumed to be extragalactic. The differential source counts for extragalactic sources in the range 0.1Jy < S_{18GHz} < 3Jy are well fitted by a relation of the form n(S)=57(S/{Jy})^{-2.2\pm0.2} [Jy^-1 sr^-1], in good agreement with the 15GHz counts published by Taylor et al. (2001) and Waldram et al. (2003). Over 70% of the extragalactic sources have a flat radio spectrum (\alpha_{0.843}^{18}> -0.5, S_{\nu}\propto\nu^{\alpha}), and 29% have inverted radio spectra (\alpha_{0.843}^{18}> 0). The optical identification rate is high: 51% of the extragalactic sources are identified with stellar objects (candidate QSOs), 22% with galaxies and only 27% with faint optical objects or blank fields.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

First results from the ATCA 18 GHz pilot survey does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with First results from the ATCA 18 GHz pilot survey, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and First results from the ATCA 18 GHz pilot survey will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-729163

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.