AzTEC millimetre survey of the COSMOS field – III. Source catalogue

We present a 0.72 deg2 contiguous 1.1-mm survey in the central area of the Cosmological Evolution Survey field carried out to a 1σ ≈ 1.26 mJy beam−1 depth with the AzTEC camera mounted on the 10-m Atacama Submillimeter Telescope Experiment. We have uncovered 189 candidate sources at a signal-to-noise ratio (S/N) ≥ 3.5, out of which 129, with S/N ≥ 4, can be considered to have little chance of being spurious (2 per cent). We present the number counts derived with this survey, which show a significant excess of sources when compared to the number counts derived from the ∼0.5 deg2 area sampled at similar depths in the Submillimetre Common-User Bolometer Array (SCUBA) HAlf Degree Extragalactic Survey (SHADES). They are, however, consistent with those derived from fields that were considered too small to characterize the overall blank-field population. We identify differences to be more significant in the S1.1mm 5 mJy regime, and demonstrate that these excesses in number counts are related to the areas where galaxies at redshifts z 1.1 are more densel