The Ultraviolet Galaxy Luminosity Function from GALEX Data: Color-Dependent Evolution at Low Redshift

We present measurements of the far-UV (FUV; 1530 Å) and near-UV (NUV; 2310 Å) galaxy luminosity functions (LFs) at low redshift (z ≤ 0.2) from Galaxy Evolution Explorer observations matched to the Two-Degree Field (2dF) Galaxy Redshift Survey. We split our FUV and NUV samples into two UV - bJ color bins and two redshift bins. As observed at optical wavelengths, the local LF of the bluest galaxies tend to have steeper faint-end slopes and fainter characteristic magnitudes M* than the reddest subsamples. We find evidence for color-dependent evolution at very low redshift in both bands, with bright blue galaxies becoming dominant in the highest redshift bin. The evolution of the total LF is consistent with an ~0.3 mag brightening between z ~ 0 and 0.13, in agreement with the first analysis of deeper GALEX fields probing adjacent and higher redshifts.