Confirmation of the effectiveness of sub-mm source redshift estimation based on rest-frame radio–FIR photometry

We present a comparison between the published optical, IR and CO spectroscopic redshifts of 15 (sub-)mm galaxies and their photometric redshifts as derived from longwavelength (radio–mm–FIR) photometric data. The redshift accuracy measured for 12 sub-mm galaxies with at least one robustly-determined colour in the radio–mm–FIR regime is δz ≈ 0.30 (r.m.s.). Despite the wide range of spectral energy distributions in the local galaxies that are used in an un-biased manner as templates, this analysis demonstrates that photometric redshifts can be efficiently derived for sub-mm galaxies with a precision of δz < 0.5 using only the rest-frame FIR to radio wavelength data.