The Wyoming Survey for Hα. III. A Multi-wavelength Look at Attenuation by Dust in Galaxies Out to z ~ 0.4

We report results from the Wyoming Survey for Hα (WySH), a comprehensive four-square degree survey to probe the evolution of star-forming galaxies over the latter half of the age of the universe. We have supplemented the Hα data from WySH with infrared data from the Spitzer Wide-area Infrared Extragalactic Survey and ultraviolet data from the Galaxy Evolution Explorer Deep Imaging Survey. This data set provides a multi-wavelength look at the evolution of the attenuation by dust, and here we compare a traditional measure of dust attenuation (L(TIR)/L(FUV)) to a diagnostic based on a recently developed robust star formation rate (SFR) indicator, [Hα_{obs}+24 μ {m}]/Hα_obs. With such data over multiple epochs, the evolution in the attenuation by dust with redshift can be assessed. We present results from the ELAIS-N1 and Lockman Hole regions at z ~ 0.16, 0.24, 0.32, and 0.40. While the ensemble averages of both diagnostics are relatively constant from epoch to epoch, each epoch individually exhibits a larger attenuation by dust for higher SFRs. Hence, an epoch-to-epoch comparison at a fixed SFR suggests a mild decrease in dust attenuation with redshift.