Spitzer view on the evolution of star-forming galaxies from z=0 to z ∼ 3

We use a 24 mu m - selected sample containing more than 8000 sources to study the evolution of star- forming galaxies in the redshift range from z = 0 to z similar to 3. We obtain photometric redshifts for most of the sources in our survey using a method based on empirically built templates spanning from ultraviolet to mid- infrared wavelengths. The accuracy of these redshifts is better than 10% for 80% of the sample. The derived redshift distribution of the sources detected by our survey peaks at around z 0: 6 1: 0 ( the location of the peak being affected by cosmic variance) and decays monotonically from z similar to 1 to z similar to 3. We have fitted infrared luminosity functions in several redshift bins in the range 0 < z less than or similar to 3. Our results constrain the density and/ or luminosity evolution of infrared- bright star- forming galaxies. The typical infrared luminosity ( L*) decreases by an order of magnitude from z similar to 2 to the present. The cosmic star formation rate ( SFR) density goes as ( 1+ z) (4. 0 +/- 0. 2) from z= 0 to 0.8. From z= 0. 8 z similar to 1. 2, the SFR density continues rising with a smaller slope. At 1: 2 < z <= 3, the cosmic SFR density remains roughly constant. The SFR density is dominated at low redshift ( z less than or similar to 0: 5) by galaxies that are not very luminous in the infrared ( L-TIR < 10(11) L-circle dot, where L-TIR is the total infrared luminosity, integrated from 8 to 1000 mu m). The contribution from luminous and ultraluminous infrared galaxies ( L-TIR > 10(11) L-circle dot) to the total SFR density increases steadily from z similar to 0 up to z similar to 2.5, forming at least half of the newly born stars by z similar to 1. 5. Ultraluminous infrared galaxies ( L-TIR > 10(12) L-circle dot) play a rapidly increasing role for z greater than or similar to 1.3.