A. J. Barger, W. -H. Wang, L. L. Cowie, F. N. Owen, C. -C. Chen, J. P. Williams
We carried out extremely sensitive Submillimeter Array (SMA) 340 GHz (860 micron) continuum imaging of a complete sample of SCUBA 850 micron sources (>4 sigma) with fluxes >3 mJy in the GOODS-N. Using these data and new SCUBA-2 data, we find that 4 of the 16 SCUBA sources are spurious. A further 3 resolve into multiple fainter SMA galaxies, suggesting that our understanding of the most luminous high-redshift dusty galaxies may not be as reliable as we thought. Ten of the 16 independent SMA sources have spectroscopic redshifts (optical/infrared or CO) to z=5.18. Using a new, ultradeep 20 cm image obtained with the Karl G. Jansky Very Large Array (rms of 2.5 microJy), we find that all 16 of the SMA sources are detected at >5 sigma. Using Herschel far-infrared (FIR) data, we show that the 5 isolated SMA sources with Herschel detections are well described by an Arp 220 spectral energy distribution template in the FIR. They also closely obey the local FIR-radio correlation, a result that does not suffer from a radio bias. We compute the contribution from the 16 SMA sources to the universal star formation rate per comoving volume. With individual star formation rates in the range 700-5000 solar masses per year, they contribute ~30% of the extinction-corrected ultraviolet selected star formation rate density from z=1 to at least z=5. Star formation histories determined from extinction-corrected ultraviolet populations and from submillimeter galaxy populations only partially overlap, due to the extreme ultraviolet faintness of some submillimeter galaxies.
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http://arxiv.org/abs/1209.1626
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