Evolution of low-frequency contribution in emission of steep-spectrum radio sources

TL;DR

This study investigates how the low-frequency emission contributions of steep-spectrum radio sources evolve with redshift, size, and age, supporting the unified model of galaxies and quasars through analysis of UTR-2 catalogue data.

Contribution

It provides new insights into the evolution of low-frequency emission in steep-spectrum radio sources and compares two types of such sources using a large catalogue.

Findings

Ratios of luminosities depend on redshift, size, and age.

Galaxies and quasars show similar mean luminosity ratios.

Results support the unified model of radio sources.

Abstract

We consider evolution properties of galaxies and quasars with steep radio spectrum at the decametre band from the UTR-2 catalogue. The ratios of source's monochromatic luminosities at the decametre and high-frequency bands display the dependence on the redshift, linear size, characteristic age of examined objects. At that, the mean values of corresponding ratios for considered galaxies and quasars have enough close quantities, testifying on the unified model of sources. We analyse obtained relations for two types of steep-spectrum sources (with linear steep spectrum (S) and low-frequency steepness after a break (C+)) from the UTR-2 catalogue.