Multifrequency study of gigahertz-peaked spectrum sources with RATAN-600

TL;DR

This study analyzes the broadband radio spectra of peaked spectrum sources over 20-30 years, revealing that high-redshift PS quasars are often contaminated by blazars and emphasizing the importance of systematic, long-term multifrequency observations.

Contribution

It provides a comprehensive multifrequency analysis of PS radio sources over decades, highlighting the contamination issues in GPS samples at high redshifts.

Findings

Only 1-2% of bright PS sources are genuine GPSs with long-term monitoring.

Blazar contamination in GPS samples increases with redshift.

Systematic multifrequency observations are crucial for accurate classification.

Abstract

We report the radio continuum properties for several samples of peaked spectrum (PS) radio sources. Broadband spectra of the objects were analysed using the RATAN-600 six-frequency (1.2-22 GHz) observations and available literature data, obtained on a time scale of 20-30 years. We discuss statistical differences in radio properties for several AGN types with peaked spectra and focus on PS quasars at high redshifts ($z > 3$). We confirm that a relatively small fraction (1-2%) of bright PS sources can be considered as genuine GPSs when they have been monitored densely and for a long time. The contamination of GPS source samples by blazars is getting stronger as the redshift increases, and we confirm that it is underestimated due to lack of systematic multifrequency observations.