SCUBA observations of COSMOS galaxies

The positional uncertainties at 450{mu}m are small (1-2.5 arcsec) and therefore allow a precise identification of multiwavelength counterparts without reliance on detection at 24{mu}m or radio wavelengths; we find that only 44% of 450{mu}m sources and 60% of 850{mu}m sources have 24{mu}m or radio counterparts. 450{mu}m selected galaxies peak at <z>=1.95+/-0.19 and 850{mu}m selected galaxies peak at <z>=2.16+/-0.11. The two samples occupy similar parameter space in redshift and luminosity, while their median SED peak wavelengths differ by ~20-50{mu}m (translating to {Delta}T_dust_=8-12K, where 450{mu}m selected galaxies are warmer).

The similarities of the 450{mu}m and 850{mu}m populations, yet lack of direct overlap between them, suggests that submillimetre surveys conducted at any single far-infrared wavelength will be significantly incomplete (>~30%) at censusing infrared-luminous star formation at high z.