The infrared emission of ultraviolet selected galaxies from z = 0 to z=1
Abstract
We select galaxies in UV rest-frame at z=0, z~0.7 and z~1 together with a sample of LBGs at z~1, the samples are built in order to sample the same range of luminosity at any redshift. The evolution of the IR and UV luminosities with z is analysed for individual galaxies as well as in terms of luminosity functions. The LIR/LUV ratio is used to measure dust attenuation. This ratio does not exhibit a strong evolution with z for the bulk of our sample galaxies but some trends are found for galaxies with a strong dust attenuation and for UV luminous sources: galaxies with LIR/LUV>10 are more frequent at z>0 than at z=0 and the largest values of LIR/LUV are found for UV faint objects; conversely the most luminous galaxies of our samples (LUV> 2 1010 Lsun$), detected at z=1, exhibit a lower dust attenuation than the fainter ones. LIR/LUV increases with the K rest-frame luminosity of the galaxies at all the redshifts considered and shows a residual anti-correlation with LUV. The most massive and UV luminous galaxies exhibit quite large specific star formation rates. LBGs exhibit systematically lower dust attenuation than UV selected galaxies of same luminosity but similar specific star formation rates. The analysis of the UV+IR luminosity functions leads to the conclusion that up to z = 1 most of the star formation activity of UV selected galaxies is emitted in IR. Whereas we are able to retrieve all the star formation from our UV selection at z=0.7, at z = 1 we miss a large fraction of galaxies more luminous than ~ 1011 Lsun. The effect is found larger for Lyman Break Galaxies.