The Star Formation Rate Function of the Local Universe

We have derived the bivariate luminosity function for the far-ultraviolet (1530 Å) and far-infrared (60 μm). We use matched GALEX and IRAS data, and redshifts from NED and the PSCz survey. We have derived a total star formation luminosity function ϕ(Ltot), with Ltot = LFUV + LFIR. Using these, we determined the cosmic "star formation rate" (SFR) function and density for the local universe. The total SFR function ϕ(Ltot) is fitted very well by a lognormal distribution over 5 decades of luminosity. We find that the bivariate luminosity function ϕ(LFUV, LFIR) shows a bimodal behavior, with LFIR tracking LFUV for Ltot < 1010 L☉ and LFUV saturating at ~1010 L☉, while Ltot ~ LFIR for higher luminosities. We also calculate the SFR density and compare it with other measurements.