Mapping out the dying phase of radio-loud AGN.
Abstract
Since their discovery in 1987, dying radio galaxies have been notoriously difficult to detect and, as such, challenge how we interpret the evolution of radio-loud active galactic nuclei (AGN). Distinguished from regular radio galaxies by the inactivity at the centre of their host galaxies, they are often referred to as remnants as their large-scale emission will remain visible for approximately 10-100 Myr after the AGN has switched off. Due to the difficulty associated with their detection and classification, fewer than fifty remnants exist within the literature. Consequently, sample studies of remnants are almost non-existent. This presents an obstacle for understanding the evolution of radio-loud AGN. Remnants encode properties such as the AGN duty cycle and the dynamical evolution of radio-loud AGN, both of which can only be inferred through sample studies of the radio galaxy population. In this talk I will present some early outcomes from a unique multi-wavelength approach performed in the GAMA 23 field. I will present an early estimate of the remnant AGN fraction in a flux-limited space and discuss what this implies about AGN evolution. I will discuss some of the emerging difficulties associated with classifying a true remnant, with potential implications on whether these objects ever truly turn off. Additionally I will discuss our future plans associated with the GAMA 23 field, and how studying remnants as a function of their radio-luminosity, redshift, and host-galaxy mass will shed new light on the evolution of radio-loud AGN.
- Publication:
-
The Build-Up of Galaxies through Multiple Tracers and Facilities
- Pub Date:
- April 2020
- DOI:
- 10.5281/zenodo.3756452
- Bibcode:
- 2020bugm.conf...16Q
- Keywords:
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- Zenodo community esoaus2020