We present total infrared ( IR ) and ultraviolet ( UV ) luminosity functions derived from large representative samples of galaxies at z \sim 0 , selected at IR and UV wavelengths from the IRAS IIFSCz catalogue , and the GALEX AIS respectively .
We augment these with deep Spitzer and GALEX imaging of galaxies in the 11 Mpc Local Volume Legacy Survey ( LVL ) , allowing us to extend these luminosity functions to lower luminosities ( \sim 10 ^ { 6 } \mathrm { L } _ { \sun } ) , and providing good constraints on the slope of the luminosity function at the extreme faint end for the first time .
Using conventional star formation prescriptions , we generate from our data the SFR distribution function for the local Universe .
We find that it has a Schechter form , that the faint-end slope has a constant value ( to the limits of our data ) of \alpha = -1.51 \pm 0.08 , and the ‘ characteristic ’ SFR \psi ^ { * } is 9.2 \mathrm { M } _ { \sun } \mathrm { yr } ^ { -1 } .
We also show the distribution function of the SFR volume density ; we then use this to calculate a value for the total SFR volume density at z \sim 0 of 0.025 \pm 0.0016 \mathrm { M } _ { \sun } \mathrm { yr } ^ { -1 } \mathrm { Mpc } ^ { -3 } , of which \sim 20 \% is occurring in starbursts .
Decomposing the total star formation by infrared luminosity , it can be seen that 9 \pm 1 \% is due to LIRGs , and 0.7 \pm 0.2 \% is occuring in ULIRGs .
By comparing UV and IR emission for galaxies in our sample , we also calculate the fraction of star formation occurring in dust obscured environments , and examine the distribution of dusty star formation : we find a very shallow slope at the highly extincted end , which may be attributable to line of sight orientation effects as well as conventional internal extinction .