The behaviour of large-scale active galactic radio jets in extragalactic environments: the case for megaparsec recollimation

Abstract

This thesis investigates large-scale galactic nuclei radio jets in extragalactic environments with a focus on understanding the physical processes behind he recollimation phenomenon. I used radio continuum observations from state-of-the art telescopes to study active galactic nuclei jets, and when available performed the infrared and X-ray analysis of their host galaxy and ambient medium of the jets. This thesis resulted in the discovery of the first large-scale recollimation jets and several more candidates in the Evolutionary Map of the Universe (EMU) pilot survey. Recollimation may occur because of external, environmental forces on the jet, or because of internal forces or instabilities in the jet. The question of how an external magnetic field affects the phenomenon remains unanswered. An in-depth analysis of Abell 3785 suggests that the jets of two galaxies appear to be superimpused along the line of sight and the bending of the jets is caused by the strong interaction with the dense intracluster medium. However, the investigation has raised further questions about the origin of the diffuse emission and the re-energising mechanism of the elongated synchrotron filaments with at least one filament originating from the Dancing Ghusts.

Date of Thesis submission	2023
Original language	English
Awarding Institution	Western Sydney University
Supervisor	Luke Barnes (Supervisor), Miroslav Filipovic (Supervisor) & Ray Norris (Supervisor)