On the relation between mini-halos and AGN feedback in clusters of galaxies. Issue 2 (1st October 2020)

• Record Type: Journal Article
• Authors: Richard-Laferrière, A; Hlavacek-Larrondo, J; Nemmen, R S; Rhea, C L; Taylor, G B; Prasow-Émond, M; Gendron-Marsolais, M; Latulippe, M; Edge, A C; Fabian, A C; Sanders, J S; Hogan, M T; Demontigny, G
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 499:Issue 2(2020)
• Page Start: 2934
• Page End: 2958
• Publication Date: 2020-10-01
• Subjects: surveys -- galaxies: clusters: individual: PKS 0745−191 -- galaxies: clusters: individual: MACS J1447.4+0827 -- galaxies: clusters: intracluster medium -- radio continuum: general -- X-rays: galaxies: clusters; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa2877
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: A variety of large-scale diffuse radio structures have been identified in many clusters with the advent of new state-of-the-art facilities in radio astronomy. Among these diffuse radio structures, radio mini-halos are found in the central regions of cool core clusters. Their origin is still unknown and they are challenging to discover; less than 30 have been published to date. Based on new VLA observations, we confirmed the mini-halo in the massive strong cool core cluster PKS 0745−191 ( z = 0.1028) and discovered one in the massive cool core cluster MACS J1447.4+0827 ( z = 0.3755). Furthermore, using a detailed analysis of all known mini-halos, we explore the relation between mini-halos and active galactic nucleus (AGN) feedback processes from the central galaxy. We find evidence of strong, previously unknown correlations between mini-halo radio power and X-ray cavity power, and between mini-halo and the central galaxy radio power related to the relativistic jets when spectrally decomposing the AGN radio emission into a component for past outbursts and one for ongoing accretion. Overall, our study indicates that mini-halos are directly connected to the central AGN in clusters, following previous suppositions. We hypothesize that AGN feedback may be one of the dominant mechanisms giving rise to mini-halos by injecting energy into the intra-cluster medium and reaccelerating an old population of particles, while sloshing motion may drive the overall shape of mini-halos inside cold fronts. AGN feedback may therefore not only play a vital role in offsetting cooling in cool core clusters, but may also play a fundamental role in re-energizing non-thermal particles in clusters.