Abstract

Lyman-Break Galaxies (LBGs) are the largest population of high-redshift (z>3) star forming galaxies and as such provide valuable insights into the mass assembly of normal galaxies during the first few Gyr of the Universe. They have moderate star formation rates (_{10s-100s Msun/yr) and they have} 10-100x higher space densities than the more extreme submillimetre galaxy population, thus they should comprise a significant portion of the far-infrared background at high redshift. But determining their true contribution to the far-infrared background has been difficult due to the rather large uncertainties that go hand-in-hand with deriving dust corrected UV luminosities and star formation rates. The only reliable way of measuring the dust content of LBGs is directly through submillimetre observations, which has had a very patchy record at best, making it difficult to say anything conclusive, until now. In this talk I will present some new results using some of the best submm data around from the SCUBA2 Cosmology Legacy Survey.