DOI

https://doi.org/10.48717/ap0f-kn04

Project

EM146

Title

Compact steep-spectrum source at the centre of a giant radio galaxy

Abstract

J084408+462744 is a giant radio galaxy (GRG) with a compact steep-spectrum central component. We observed it with e-MERLIN at L- and C-bands and it turned out to be a double. Spectral indices of those two sub-components are completely different. While the NE feature has a very steep spectrum, the spectrum of the SW one is inverted. It is, therefore, likely that the NE sub-component is a relic mini-lobe and the SW is a core. We propose to verify that conjecture with the EVN + e-MERLIN observations because both sub-arcsecond-scale components of J084408+462744 remain unresolved by e-MERLIN alone. When fuelling by the central engine is cut off, hotspots disperse much quicker than the lobes hosting them. Therefore, lack of a hotspot within the NE lobe seen in the EVN image would ultimately justify labelling that lobe a relic. Confirming the absence of the hotspot is the primary scientific goal of this project. The secondary goal is to find (at least a trace of) the other mini-lobe located on the SW side of the core. We suspect it may be even more decayed than the visible NE mini-lobe.