UV to IR SEDs of UV-Selected Galaxies in the ELAIS Fields: Evolution of Dust Attenuation and Star Formation Activity from z = 0.7 to 0.2

摘要

We study the ultraviolet to far-infrared (hereafter UV-to-IR) SEDs of a sample of intermediate-redshift (0.2 ≤ z ≤ 0.7) UV-selected galaxies from the ELAIS N1 and ELAIS N2 fields by fitting a multi-wavelength data set to a library of GRASIL templates. Star formation related properties of the galaxies are derived from the library of models by using Bayesian statistics. We find a decreasing presence of galaxies with low attenuation and low total luminosity as redshift decreases, which does not hold for high total luminosity galaxies. In addition, the dust attenuation of low-mass galaxies increases as redshift decreases, and this trend seems to disappear for galaxies with M* ≥ 1011 M☉. This result is consistent with a mass-dependent evolution of the dust-to-gas ratio, which could be driven by a mass-dependent efficiency of star formation in star-forming galaxies. The specific star formation rates (SSFR) decrease with increasing stellar mass at all redshifts, and for a given stellar mass the SSFR decreases with decreasing redshift. The differences in the slope of the M*-SSFR relation found between this work and others at similar redshift could be explained by the adopted selection criteria of the samples, which for a UV-selected sample, favors blue, star-forming galaxies.