EVOLUTION OF THE JET EMISSION OF RADIO SOURCES WITH THE STEEP LOW-FREQUENCY SPECTRA

We suppose the relation of source emission at the decameter and infrared bands as the estimate of the jet structure contribution relatively the central region of the source. This relation is examined for the sample of galaxies and quasars with steep low-frequency spectra from the UTR-2 catalogue. We have derived the relations of corresponding flux densities (at the frequency 25 MHz and at the frequency 1.38‧1014 Hz (near-infrared band)) and their connection with source’s redshifts, characteristic ages, jet propagation velocities. At the same value of the jet emission relation (at the separate value of this relation) the very close values of the characteristic age and the jet propagation velocity are derived for the examined galaxies and quasars with the same steep-spectrum type. So, the evolution of the galaxies and quasars with the steep linear radio spectrum (type S) may be similar. Analogously, one is similar for galaxies and quasars with the steep break radio spectrum (type C+). The considered relations have positive correlation for the corresponding redshifts, the jet propagation velocity. The radio sources with the steep linear spectrum display the smaller characteristic age (~107 years) than ones with the steep break spectrum (~108 years). And the obtained mean values of the jet propagation velocity for the examined galaxies and quasars with the steep linear spectrum (~109 cm/s) are more by one order than these for the examined galaxies and quasars with the steep break spectrum (~108 cm/s). The derived results may evidence for the cyclic activity of the steep-spectrum radio sources.