AzTEC millimetre survey of the COSMOS field – I. data reduction and source catalogue
We present a 1.1mm wavelength imaging survey covering 0.3 deg^2 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 deg^2 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 × 10^(12)L_☉ and star formation rates ≥1100M_☉ 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.
Additional Information©2008 The Authors. Journal compilation ©2008 RAS. Accepted 2008 January 17. Received 2008 January 16; in original form 2007 November 16. The authors are grateful to J. Aguirre, J. Karakla, K. Souccar, I. Coulson, R. Tilanus, R. Kackley, D. Haig, S. Doyle, J. Lowenthal and the observatory staff at the JCMT who made these observations possible. Support for this work was provided in part by the NSF grant AST 05-40852 and the grant from the Korea Science & Engineering Foundation (KOSEF) under a cooperative Astrophysical Research Centre of the Structure and Evolution of the Cosmos (ARCSEC). IA and DH acknowledge partial support by CONACyT from research grants 39953-F and 39548-F. This research has made use of the NASA/IPAC Extragalactic Database which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.
Published - SCOmnras08.pdf