2007ApJS..173..432X

We study dust attenuation and stellar mass of z∼0.6 star-forming galaxies using new SWIRE observations in IR and GALEX observations in UV. Two samples are selected from the SWIRE and GALEX source catalogs in the SWIRE/GALEX field ELAIS-N1-00 (Ω=0.8 deg²). The UV-selected sample has 600 galaxies with photometric redshift (hereafter photo-z) 0.5≤z≤0.7 and NUV≤23.5 (corresponding to L_FUV≥10^9.6 L_☉). The IR-selected sample contains 430 galaxies with f_24µm≥0.2 mJy (L_dust≥10^10.8 L_☉) in the same photo-z range. It is found that the mean L_dust/L_FUV ratios of the z=0.6 UV galaxies are consistent with that of their z=0 counterparts of the same L_FUV. For IR galaxies, the mean L_dust/L_FUV ratios of the z=0.6 LIRGs (L_dust∼10¹¹ L_☉) are about a factor of 2 lower than local LIRGs, whereas z=0.6 ULIRGs (L_dust∼10¹² L_☉) have the same mean L_dust/L_FUV ratios as their local counterparts. This is consistent with the hypothesis that the dominant component of LIRG population has changed from large, gas-rich spirals at z>0.5 to major mergers at z=0. The stellar mass of z=0.6 UV galaxies of L_FUV≤10^10.2 L_☉ is about a factor of 2 less than their local counterparts of the same luminosity, indicating growth of these galaxies. The mass of z=0.6 UV luminous galaxies (UVLGs: L_FUV>10^10.2 L_☉) and IR-selected galaxies, which are nearly exclusively LIRGs and ULIRGs, is the same as their local counterparts.