The relationship between the radio core-dominance parameter and spectral index in different classes of extragalactic radio sources (III)

TL;DR

This study analyzes the relationship between radio core-dominance parameters and spectral indices across various extragalactic radio source classes, revealing significant differences and a consistent correlation among them.

Contribution

It provides a comprehensive analysis of a large sample of 966 sources, extending previous work by confirming the correlation across diverse AGN types.

Findings

Core-dominance parameters differ significantly among source classes.

A consistent correlation exists between core-dominance and spectral index.

The correlation extends across all source types in the sample.

Abstract

Active galactic nuclei (AGNs) can be divided into two major classes, namely radio-loud and radio-quiet AGNs. A small subset of the radio-loud AGNs is called blazars, which are believed to be unified with Fanaroff-Riley type I and type II (FRI&II) radio galaxies. Following our previous work, we present a latest sample of 966 sources with measured radio flux densities of the core and extended components. The sample includes 83 BL Lacs, 473 FSRQs, 101 Seyferts, 245 galaxies, 52 FRIs&IIs and 12 unidentified sources. We then calculate the radio core-dominance parameters and spectral indices and study their relationship. Our analysis shows that the core-dominance parameters and spectral indices are quite different for different types of sources. We also corroborate that the correlation between core-dominance parameter and radio spectral index extends over all the sources in a large sample presented.