Small and young radio sources

TL;DR

This paper discusses the significance of high frequency peaker radio sources as very young objects, emphasizing the role of VLBI observations in understanding their physical conditions and evolution.

Contribution

It highlights the importance of VLBI data in constraining physical conditions and environmental effects in young radio sources, advancing models of their evolution.

Findings

HFP sources are likely extremely young radio objects.

VLBI provides critical insights into source physical conditions.

Environmental factors influence the growth of young radio sources.

Abstract

It is currently accepted that compact and bright radio sources characterized by a convex spectrum peaking at frequencies ranging from 100 MHz to a few GHz are young objects. In this scenario, high frequency peaker (HFP) radio sources, with a turnover frequency higher than 5 GHz are good candidates to be extremely young radio sources with ages of up to a few thousand years. The knowledge of the conditions in young radio source is fundamental in order to draw reliable evolution models able to describe the entire life-cycle of the radio emission. Given the high spatial resolution and the large frequency range spanned, VLBI observations provide a unique opportunity to constrain the physical conditions in young radio sources, and to investigate the role played by the environment on the source growth.