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Description
We present the Herschel Bright Sources (HerBS) sample, a sample of bright, high-redshift Herschel sources detected in the 616.4deg^2^ Herschel Astrophysical Terahertz Large Area Survey. The HerBS sample contains 209 galaxies, selected with a 500um flux density greater than 80mJy and an estimated redshift greater than 2. The sample consists of a combination of hyperluminous infrared galaxies and lensed ultraluminous infrared galaxies during the epoch of peak cosmic star formation. In this paper, we present Submillimetre Common-User Bolometer Array 2 (SCUBA-2) observations at 850um of 189 galaxies of the HerBS sample, 152 of these sources were detected. We fit a spectral template to the Herschel-Spectral and Photometric Imaging Receiver (SPIRE) and 850um SCUBA-2 flux densities of 22 sources with spectroscopically determined redshifts, using a two-component modified blackbody spectrum as a template. We find a cold- and hot-dust temperature of 21.29^+1.35^_-1.66_ and 45.80^+2.88^_-3.48_K, a cold-to-hot dust mass ratio of 26.62^+5.61^_-6.74_ and a {beta} of 1.83^+0.14^_-0.28_. Thee poor quality of the fit suggests that the sample of galaxies is too diverse to be explained by our simple model. Comparison of our sample to a galaxy evolution model indicates that the fraction of lenses are high. Out of the 152 SCUBA-2 detected galaxies, the model predicts 128.4+/-2.1 of those galaxies to be lensed (84.5 per cent). The SPIRE 500um flux suggests that out of all 209 HerBS sources, we expect 158.1+/-1.7 lensed sources, giving a total lensing fraction of 76 per cent.
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