Galaxy evolution, deep galaxy counts, and the near-infrared cosmic infrared background

Accurate synthetic models of stellar populations are constructed and used in evolutionary models of stellar populations in forming galaxies. Following their formation, the late-type galaxies are assumed to follow the Schmidt law for star formation, while early-type galaxies are normalized to the present-day fundamental plane relations assumed to mimic the metallicity variations along their luminosity sequence. The stars in disks of galaxies are distributed with the Scale IMF and in spheroids with the Salpeter IMF. We show that these assumptions reproduce extremely well the recent observations for the evolution of the rate of star formation with redshift. We then compute predictions of these models for the observational data at early epochs for various cosmological parameters Omega, Omega(Lambda), and H-0. We find good match to the metallicity data from the damped Ly alpha systems and the evolution of the luminosity density out to z similar or equal to 1. Likewise, our models produce good fits for low values of Omega to the deep number counts of galaxies in all bands where data are available; this is done without assuming existence of extra populations of galaxies at high z. Our models also match the data on the redshift distribution of galaxy counts in B and K bands. They also provide good fits to the observed colors. We compute the predicted mean levels and angular distribution of the cosmic infrared background produced from the early evolution of galaxies. The predicted fluxes and fluctuations are still below the current observational limits, but not by a large factor. Finally, we find that the recent detection of the diffuse extragalactic light in the visible bands requires for our models a high redshift of galaxy formation, z(f) greater than or equal to (3-4); otherwise, the produced flux of the extragalactic light at optical bands exceeds the current observational limits.