Steep-spectrum sources of the RCR catalog in the millimeter and submillimeter ranges based on Planck data.

We have investigated the regions of cosmic microwave background maps from the Planck experiment in the neighborhoods of radio sources from the RCR catalog. Based on the measurements of sources from the Planck catalog, we have constructed the calibration curves to determine the brightness of objects. For 34 steep-spectrum objects, for the first time we have estimated the flux densities at millimeter and submillimeter wavelengths, constructed the spectra, made identifications, and gathered information available in databases. Faint, difficult-to-clean, microwave sources make an additional contribution to the secondary anisotropy on angular scales <7′. [ABSTRACT FROM AUTHOR]