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

作者：裴致远; Jun-Hui Fan; Denis Bastieri^*; 杨江河; 肖胡兵; 杨文馨

来源：Research in Astronomy and Astrophysics, 2020, 20(02): 89-99.

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 flat spectrum radio quasars,101 Seyferts,245 galaxies,52 FRIs&Ⅱs and12 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 confirm that the correlation between core-dominance parameter and radio spectral index extends over all the sources in a large sample presented.