High-resolution SMA imaging of bright submillimetre sources from the SCUBA-2 Cosmology Legacy Survey

Citations Over TimeTop 10% of 2018 papers

Abstract

We have used the Submillimeter Array at 860 m to observe the brightest SCUBA-2 sources in 4 deg 2 of the Cosmology Legacy Survey. We have targeted 75 of the brightest single-dish SCUBA-2 850 m sources down to S 850 8 mJy, achieving an average synthesized beam of 2.4 arcsec and an average rms of 860 = 1.5 mJy in our primary beamcorrected maps. We searched our maps for 4 peaks, corresponding to S 860 6 mJy sources, and detected 59 single galaxies and three pairs of galaxies. We include in our study 28 archival observations, bringing our sample size to 103 bright singledish submillimetre sources with interferometric follow-up. We compute the cumulative and differential number counts of our sample, finding them to overlap with previous single-dish survey number counts within the uncertainties, although our cumulative number count is systematically lower than the parent SCUBA-2 cumulative number count by 24 6 per cent between 11 and 15 mJy. We estimate the probability that a 10 mJy single-dish submillimetre source resolves into two or more galaxies with similar flux densities, causing a significant change in the number counts, to be about 15 per cent. Assuming the remaining 85 per cent of the targets are ultra-luminous starburst galaxies between z = 2-3, we find a likely volume density of 400 M yr -1 sources to be 3 +0.7 -0.6 10 -7 Mpc -3 . We show that the descendants of these galaxies could be 4 10 11 M local quiescent galaxies, and that about 10 per cent of their total stellar mass would have formed during these short bursts of star-formation.

Related Papers

• → The luminosity-dependent high-redshift turnover in the steep spectrum radio luminosity function: clear evidence for downsizing in the radio-AGN population(2011)72 cited
• → Discerning dark energy models with high redshift standard candles(2017)4 cited
• → Do Number Counts Tell us Anything about the Distribution of Distant Sources?(1973)2 cited