The detection of FIR emission from high redshift star-forming galaxies in the ECDF-S

We have used the Large Apex Bolometer Camera (LABOCA) Survey of the Ex-tended Chandra Deep Field South (LESS) to investigate rest-frame FIR emission from typical star-forming systems (Lyman Break Galaxies, LBGs, and Lyman-α emitters, LAEs) at redshift 3, 4, 4.5 and 5 (922, 68, 46, and 20 sources respectively). We initially concentrate on LBGs at z ∼ 3 and select three subsamples on stellar mass (rest-frame optical-brightest, M ∗> 10.10.25M), extinction corrected star-formation (assuming βUV = −2 and applying a dust attenuation correction, SFRtot> 6.7M yr−1) and rest-frame UV-magnitude (representing a typical Lyman-break selection with R < 24.43). We produce composite 870µm images of the typical source in our subsamples, obtaining ∼ 4σ detections (0.61 mJy and 0.35 mJy and 0.37 mJy respectively) and suggesting a correlation between FIR luminosity and stellar mass. We apply a similar procedure to our full samples at z ∼ 3, 4, 4.5 and 5 and do not obtain detections-a result that is consistent with a simple scaling between FIR luminosity and stellar mass. In order to constrain the FIR SED of these systems we explore their emission a