1307.0971 (I. Oteo et al.)

The UV to FIR spectral energy distribution of star-forming galaxies in the redshift desert    [PDF]

I. Oteo, Á. Bongiovanni, G. Magdis, A. M. Pérez-García, J. Cepa, B. Cedrés, H. Domínguez Sánchez, A. Ederoclite, M. Sánchez-Portal, R. Pérez-Martínez, I. Pintos-Castro, J. Polednikova

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.

View original: http://arxiv.org/abs/1307.0971