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

We use a 24 μm-selected sample containing more than 8000 sources to study the evolution of star-forming galaxies in the redshift range from z = 0 to z ∼ 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 ∼ 1 to z ∼ 3. We have fitted infrared luminosity functions in several redshift bins in the range 0 < z ≲ 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 ∼ 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 to z ∼ 1.2, the SFR density continues rising with a smaller slope. At 1.2 < z ≲ the cosmic SFR density remains roughly constant. The SFR density is dominated at low redshift (z ≲ 0.5) by galaxies that are not very luminous in the infrared (L_TIR < 10¹¹ L_⊙, where L_TIR is the total infrared luminosity, integrated from 8 to 1000 μm). The contribution from luminous and ultraluminous infrared galaxies (L_TIR > 10¹¹ L_⊙) to the total SFR density increases steadily from z ∼ 0 up to z ∼ 2.5, forming at least half of the newly born stars by z ∼ 1.5. Ultraluminous infrared galaxies (L_TIR > 10¹² L_⊙) play a rapidly increasing role for z ≳1.3.