The UV to FIR spectral energy distribution of star-forming galaxies in
  the redshift desert
  We analyse the rest-frame UV-to-NIR spectral energy distribution (SED) of
Lyman break galaxies (LBGs), star-forming (SF) BzK (sBzK), and UV-selected
galaxies at 1.5 < z < 2.5 in the COSMOS, GOODS-N, and GOODS-S fields.
Additionally, we complement the multi-wavelength coverage of the galaxies
located in the GOODS fields with deep FIR data taken from the GOODS-Herschel
project. We find that sBzK galaxies represent the general population of SF
galaxies at z ~ 2 better than LBGs. For a given stellar mass, LBGs tend to have
bluer optical colours than sBzK and UV-selected galaxies. We find clean PACS
individual detections for a subsample of 48 LBGs, 89 sBzK, and 91 UV-selected
galaxies, that measure their dust emission directly. Their SFR_total = SFR_UV +
SFR_IR cannot be recovered with the dust-correction factors derived with their
continuum slope and the IRX-beta relations for local starbursts. This has
implications, for example, in the definition of the main sequence (MS) at z ~
2. PACS-detected galaxies are located above the z ~ 2 MS and thus their star
formation is probably driven by starburst. This is in agreement with the shape
of their IR SEDs. PACS-detected galaxies with redder UV continuum slope and
higher stellar mass are more attenuated. We find that for a given UV continuum
slope the dustiest galaxies at higher redshifts are more attenuated and that
for a given stellar mass the dustiest galaxies at higher redshifts have
stronger FIR emission. This suggests an evolution of their dust properties.
However, we do not find significant evolution in the relation between dust
attenuation and stellar mass with redshift, at least at z < 2.5. There is a
subpopulation of 17, 26, and 27 LBGs, sBzK, and UV-selected galaxies,
respectively, that are detected in any of the SPIRE bands. We speculate that
SPIRE-detected LBGs are the bridging population between sub-mm galaxies and
LBGs.
