Evolution of Lyα galaxies: Stellar populations at z ∼ 0.3

Abstract

We present the results of a stellar population analysis of 30 Lyα emitting galaxies (LAEs) at z ∼ 0.3, previously discovered with the Galaxy Evolution Explorer.With a few exceptions, we can accurately fit model spectral energy distributions to these objects, representing the first time this has been done for a large sample of LAEs at z < 3, a gap of ∼8 Gyr in the history of the universe. From the 26/30 LAEs which we can fit, we find an age and stellar mass range of 200 Myr-10 Gyr and 109-1011M, respectively. These objects thus appear to be significantly older and more massive than LAEs at high redshift. We also find that these LAEs show a mild trend toward higher metallicity than those at high redshift, as well as a tighter range of dust attenuation and interstellar medium geometry. These results suggest that low-redshift LAEs have evolved significantly from those at high redshift.