The UV to FIR spectral energy distribution of star-forming galaxies in the redshift desert
We analyze the rest-frame UV-to-near-IR 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-North,
and GOODS-South fields. Additionally, we complement the multi-wavelength
coverage of the galaxies located in GOODS-North and GOODS-South fields
with deep FIR data taken within the framework of the GOODS-Herschel
project. According to their best-fitted SED-derived properties we find
that, due to their selection criterion involving UV measurements, LBGs
tend to be UV-brighter, bluer, have less prominent Balmer break (are
younger), and have higher dust-corrected total SFR than sBzK galaxies.
In a color versus stellar mass diagram, LBGs at z ~ 2 tend to be mostly
located over the blue cloud of galaxies at their redshift, although
galaxies with older ages, higher dust attenuation, and redder UV
continuum slope deviate to the green valley and red sequence. We find
PACS (100um or 160um) individual detections for a subsample of 77 LBGs,
140 sBzK, and 144 UV-selected galaxies. The total SFR of the studied
PACS-detected galaxies cannot be recovered with the dust-correction
factors derived with their continuum slope and the IRX-beta relations
for local star-burst, similar to what it happens at higher redshifts. In
an SFR-mass diagram, the studied PACS-detected galaxies are located
above the Daddi et al. (2007) main sequence and, therefore, their
star-formation is likely driven by star-burst. There is a subpopulation
of 26 and 49 LBGs and sBzK galaxies, respectively, that are detected in
SPIRE (250um, 350um, or 500um) bands. We speculate that this population
of SPIRE-detected LBGs is the bridge population between sub-mm galaxies
and LBGs. Finally, we find that the IR properties of the dustiest LBGs
have changed with redshift, indicating an evolution that is in agreement
with previous results.