Sub-kpc radio jets in the brightest central galaxy of the cool-core galaxy cluster RXJ1720.1+2638

TL;DR

This paper presents high-resolution observations revealing sub-kiloparsec radio jets in the central galaxy of a cool-core cluster, suggesting ongoing activity that could explain the origin of the cluster's radio minihalo.

Contribution

The study provides the first direct evidence of active sub-kpc jets in the brightest galaxy of RXJ1720.1+2638, linking jet activity to minihalo formation.

Findings

Detection of sub-kpc jets in the central galaxy.

Implication of ongoing jet activity for minihalo origin.

Supports continuous electron injection hypothesis.

Abstract

The cool-core galaxy cluster RXJ1720.1+2638 hosts extended radio emission near the cluster core, known as a minihalo. The origin of this emission is still debated and one piece of the puzzle has been the question of whether the supermassive black hole in the brightest central galaxy is actively powering jets. Here we present high-resolution e-MERLIN observations clearly indicating the presence of sub-kpc jets; this may have implications for the proposed origin of the minihalo emission, providing an ongoing source of relativistic electrons rather than a single burst sometime in the past, as previously assumed in simulations attempting to reproduce observational characteristics of minihalo-hosting systems.