Star formation rate density across the cosmic time

We present the star formation rates (SFRs) of galaxies with redshifts of 0 < z < 6 and cosmic star formation rate densities as a function of redshift. The SFRs for the galaxies at infrared emission have been investigated for 1752 sources from the Spitzer 70 μm observations of the Spitzer COSMOS Legacy survey and the various surveys in the literature. Analyzing the SFRs of these objects provides the distribution of SFRs across the redshift range. We have derived the star formation rate densities (SFRDs) based on the present analysis of SFRs and comoving volume calculated from the cosmic parameters we have used. Our results show a slightly steeper slope at lower and intermediate redshift, 0 < z < 2. We have found a steep decline of SFRD from z=1 to 0, but measured a peak of SFRD at z≈ 2.2-2.4 .