AzTEC half square degree survey of the SHADES fields - II. Identifications, redshifts, and evidence for large-scale structure

摘要: The Astronomical Thermal Emission Camera (AzTEC) 1.1 mm survey of the two SCUBA HAlf Degree Extragalactic Survey (SHADES) fields is largest (0.7 deg2) blank-field millimetre-wavelength (mm-wavelength) undertaken to date at a resolution ≃18 arcsec and depth ≃1 mJy. We have used deep optical radio multiwavelength data in SHADES Lockman Hole East SXDF/UDS obtain galaxy identifications for ≃64 per cent (≃80 including tentative identifications) 148 AzTEC-SHADES sources reported by Austermann et al., exploiting 24 μm complemented methods based on 8 flux density red optical–infrared (i − K) colour. This unusually high identification rate can be attributed relatively bright mm-wavelength threshold, combined with supporting multifrequency now available these well-studied fields. further exploited optical–mid-infrared–radio derive an ≃60 (≃75 complete redshift distribution sources, yielding median z ≃ 2.2, high-redshift tail extending least 4. Despite larger area probed AzTEC relative original SCUBA-SHADES imaging, consistent that displayed reinforces evidence mm/submm field significantly different from found field. Comparison simulated surveys similar scale extracted semi-analytic models Millennium simulation indicates this as expected if are massive (M > 1011 M⊙) star-forming galaxies tracing large-scale structures over scales 10–20 Mpc. confirms importance covering several deg2 (as underway SCUBA2) representative samples (sub)mm-selected galaxies. work provides foundation exploitation Spitzer Herschel study stellar masses specific star formation rates most active cosmic history.