The GALEX-SDSS NUV and FUV flux density and local star formation rate

We calculate the local ultraviolet (UV) flux density in the Galaxy Evolution Explorer (GALEX) Medium Imaging Survey (MIS) far-UV (FUV) and near-UV (NUV) bands using redshifts provided by Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7). Luminosity functions are calculated for the overlapping MIS and SDSS sample, allowing flux densities to be measured and the local star formation rate (SFR) to be calculated using volumes much larger than previous FUV-based estimates. We calculate flux densities for a dust-corrected low-redshift (0.013 < z < 0.1) sample of f(nu-FUV) = 22.24 +/- 3.13 x 1025 h erg s-1 Hz-1 Mpc-3, f(nu-NUV) = 38.54 +/- 5.30 x 1025 h erg s-1 Hz-1 Mpc-3. The SFR density found is 0.0312 +/- 0.0045 h M-circle dot yr-1 Mpc-3. This is larger than published rates recently found using the UV implied SFR, though the major discrepancy is the correction made for dust attenuation and once this is dealt with consistently the results agree well. These values are also consistent with recent H alpha derived SFRs. Once cosmic variance is taken into account most of the recent SFRs at low redshift (z < 0.3) found in the literature can be brought into agreement, however, the lowest redshift values (z < 0.045) do appear to be significantly lower.