Photometric study of radio galaxies in the RATAN-600 "Cold" survey

About 100 steep-spectrum radio sources from the RATAN-600 RC catalog were mapped by the VLA and identified with optical objects down to 24(m)-25(m) in the R band using the 6-m telescope. An updated list of calibrators with known redshifts of the same class of RGs was compiled to evaluate the accuracy of photometric redshift estimates. BVRI photometry for 60 RC objects was performed with the 6-m telescope, and by standard model fitting we have estimated color redshifts and ages of the stellar populations of the host gE galaxies. The mean redshift of FR II RGs from the RC list turned out to be approximate to1. Several objects were found in which active star formation began in the first billion years after the Big Bang.