The relation between the radio emission of the core and host galaxy properties in Fanaroff–Riley type II radio galaxies
Farideh Mazoochi (IPM)
20 Dec 2022
The presence of supermassive accreting black holes at the centres of massive galaxies is associated with significant radiation at all wavelengths. This is a main feature that distinguishes galaxies with active nuclei from normal. In this survey, we study the core radio power of active galaxies and its relation to the optical properties of the host galaxy in samples of high-excitation (HERG) and low-excitation (LERG) Fanaroff–Riley type II (FRII) radio galaxies. FRIIs are powerful edgebrightened jets that contain weaker radio emissions in their cores.In our study, the radio galaxy sample is divided into two groups of core/non-core FRII, based on the existence of strong, weak or lack of single radio core component. We show that FRII LERGs with radio emission of the core have significantly higher [O III] line luminosities compared to the non-core LERG FRIIs. There is no significant difference between the hosts of the core and non-core FRIIs of LERG type in galaxy sizes, concentration indices, star formation rates, 4000-Å break strengths, colours, black hole masses, and black hole to stellar masses. We argue that the detection of higher [O III] luminosities in the core FRIIs may indicate the presence of higher amounts of gas, very close to the active galactic nuclei (AGN) nucleus in the core FRIIs compared to the non-core FRIIs or may result from the interaction of the radio jets with this gas. The effect of relativistic beaming on the radio luminosities and the contribution of restating AGN activity have also been considered.
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