AzTEC millimetre survey of the COSMOS field – I. Data reduction and source catalogue |
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| Authors: | K S Scott J E Austermann T A Perera G W Wilson I Aretxaga J J Bock D H Hughes Y Kang S Kim P D Mauskopf D B Sanders N Scoville M S Yun |
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| Institution: | Department of Astronomy, University of Massachusetts, Amherst, MA 01003, USA;Instituto Nacional de Astrofísica, Óptica y Electrónica, Tonantzintla, Puebla, México;Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA;Astronomy &Space Science Department, Sejong University, Seoul, South Korea;Physics and Astronomy, Cardiff University, Wales;Institute for Astronomy, University of Hawaii, Honolulu, HI 96822, USA;California Institute of Technology, Pasadena, CA 91125, USA |
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| Abstract: | We present a 1.1 mm wavelength imaging survey covering 0.3 deg2 in the COSMOS field. These data, obtained with the AzTEC continuum camera on the James Clerk Maxwell Telescope, were centred on a prominent large-scale structure overdensity which includes a rich X-ray cluster at z ≈ 0.73. A total of 50 mm-galaxy candidates, with a significance ranging from 3.5 to 8.5σ, are extracted from the central 0.15 deg2 area which has a uniform sensitivity of ～1.3 mJy beam?1. 16 sources are detected with S/N ≥ 4.5, where the expected false-detection rate is zero, of which a surprisingly large number (9) have intrinsic (deboosted) fluxes ≥5 mJy at 1.1 mm. Assuming the emission is dominated by radiation from dust, heated by a massive population of young, optically obscured stars, then these bright AzTEC sources have far-infrared luminosities >6 × 1012 L⊙ and star formation rates >1100 M⊙ yr?1 . Two of these nine bright AzTEC sources are found towards the extreme peripheral region of the X-ray cluster, whilst the remainder are distributed across the larger scale overdensity. We describe the AzTEC data reduction pipeline, the source-extraction algorithm, and the characterization of the source catalogue, including the completeness, flux deboosting correction, false-detection rate and the source positional uncertainty, through an extensive set of Monte Carlo simulations. We conclude with a preliminary comparison, via a stacked analysis, of the overlapping MIPS 24-μm data and radio data with this AzTEC map of the COSMOS field. |
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| Keywords: | galaxies: high-redshift galaxies: starburst submillimetre |
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