Probing the submillimetre number counts at f(850 mu m) < 2mJy
Abstract
We have conducted a submillimetre mapping survey of faint, gravitationally lensed sources, where we have targeted 12 galaxy clusters and additionally the New Technology Telescope (NTT) Deep Field. The total area surveyed is 71.5 arcmin^(2) in the image plane; correcting for gravitational lensing, the total area surveyed is 40 arcmin^(2) in the source plane for a typical source redshift z approximate to 2.5. In the deepest maps, an image plane depth of 1sigma rms similar to 0.8 mJy is reached. This survey is the largest survey to date to reach such depths. In total 59 sources were detected, including three multiply imaged sources. The gravitational lensing makes it possible to detect sources with flux density below the blank field confusion limit. The lensing-corrected fluxes range from 0.11 to 19 mJy. After correcting for multiplicity, there are 10 sources with fluxes < 2 mJy of which seven have submJy fluxes, doubling the number of such sources known. Number counts are determined below the confusion limit. At 1 mJy, the integrated number count is similar to 10^(4) deg^(-2), and at 0.5 mJy it is similar to 2 x 10^(4) deg^(-2). Based on the number counts, at a source plan flux limit of 0.1 mJy, essentially all of the 850-mu m background emission has been resolved. The dominant contribution (> 50 per cent) to the integrated background arises from sources with fluxes S-850 between 0.4 and 2.5 mJy, while the bright sources S-850 > 6 mJy contribute only 10 per cent.
Additional Information
© 2008 The Authors. Journal compilation © 2008 RAS. Accepted 2007 December 5. Received 2007 October 24; in original form 2007 January 14. Published Online: 7 February 2008. We thank Vicki Barnard, Tracy Webb, Marijn Franx and Graham Smith for fruitful discussions. We are grateful to Patricio Vielva and his colleagues for useful discussions regarding wavelets and letting us use their software. We thank an anonymous referee for constructive comments, which helped improve the manuscript. The JCMT is operated by the Joint Astronomy Centre on behalf of the Science and Technology Facilities Council of the United Kingdom, the Netherlands Organization for Scientific Research and the National Research Council of Canada. KKK acknowledges support by the Netherlands Organization for Scientific Research (NWO) and the Leids Kerkhoven-Bosscha Fonds for travel support. JPK acknowledges support from Caltech and CNRS.Attached Files
Published - KNUmnras08.pdf
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Additional details
- Eprint ID
- 13233
- Resolver ID
- CaltechAUTHORS:KNUmnras08
- Science and Technology Facilities Council (STFC)
- Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)
- National Research Council of Canada
- Leids Kerkhoven-Bosscha Fonds
- Caltech
- Centre National de la Recherche Scientifique (CNRS)
- Created
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2009-02-11Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field