Moircs deep survey. VIII. Evolution of star formation activity as a function of stellar mass in galaxies since z ∼ 3

We study the evolution of star formation activity of galaxies at 0.5 < z < 3.5 as a function of stellar mass, using very deep NIR data taken with the Multi-Object Infrared Camera and Spectrograph on the Subaru telescope in the GOODS-North region. The NIR imaging data reach K ∼ 23-24 Vega magnitude and they allow us to construct a nearly stellar-mass-limited sample down to ∼10^9.5-10 M_⊙ even at z ∼ 3. We estimated star formation rates (SFRs) of the sample with two indicators, namely, the Spitzer/MIPS 24 μm flux and the rest-frame 2800 Å luminosity. The SFR distribution at a fixed M_star shifts to higher values with increasing redshift at 0.5 < z < 3.5. More massive galaxies show stronger evolution of SFR at z ≳ 1. We found galaxies at 2.5 < z < 3.5 show a bimodality in their SSFR distribution, which can be divided into two populations by a constant SSFR of ∼ 2 Gyr^-1. Galaxies in the low-SSFR group have SSFRs of ∼ 0.5-1.0 Gyr^-1, while the high-SSFR population shows ∼ 10 Gyr^-1. The cosmic SFR density (SFRD) is dominated by galaxies with M_star = 10^10-11M_⊙ at 0.5 < z < 3.5, while the contribution of massive galaxies with M _star = 10^11-11.5 M_⊙ shows a strong evolution at z > 1 and becomes significant at z ∼ 3, especially in the case with the SFR based on MIPS 24 μm. In galaxies with M_star = 10^10-11.5 M_⊙, those with a relatively narrow range of SSFR (≲1 dex) dominates the cosmic SFRD at 0.5 < z < 3.5. The SSFR of galaxies that dominate the SFRD systematically increases with redshift. At 2.5 < z < 3.5, the high-SSFR population, which is relatively small in number, dominates the SFRD. Major star formation in the universe at higher redshift seems to be associated with a more rapid growth of stellar mass of galaxies.