Oxford University Press (OUP), Monthly Notices of the Royal Astronomical Society, 2(441), p. 1017-1039
DOI: 10.1093/mnras/stu510
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We present a comparison of the physical properties of a rest-frame $250μ$m selected sample of massive, dusty galaxies from $01$ SMGs have an average SFR of $390^{+80}_{-70}\,$M$_⊙$yr$^{-1}$ which is 120 times that of the low-redshift sample matched in stellar mass to the SMGs (SFR$=3.3\pm{0.2}$ M$_⊙$yr$^{-1}$). The SMGs harbour a substantial mass of dust ($1.2^{+0.3}_{-0.2}\times{10}^9\,$M$_⊙$), compared to $(1.6±0.1)\times{10}^8\,$M$_⊙$ for low-redshift dusty galaxies. At low redshifts the dust luminosity is dominated by the diffuse ISM, whereas a large fraction of the dust luminosity in SMGs originates from star-forming regions. At the same dust mass SMGs are offset towards a higher SFR compared to the low-redshift H-ATLAS galaxies. This is not only due to the higher gas fraction in SMGs but also because they are undergoing a more efficient mode of star formation, which is consistent with their bursty star-formation histories. The offset in SFR between SMGs and low-redshift galaxies is similar to that found in CO studies, suggesting that dust mass is as good a tracer of molecular gas as CO. ; Comment: 17 pages, 8 pages in Appendix, 12 figures, 2 tables. Accepted for publication in MNRAS. Minor typos corrected to match published version