Informazioni sull’evento


Coffee talks

Friday 21/04/2023 @ 11:30, Sala riunioni quarto piano e on-line (

Andrea Botteon (INAF-IRA Bologna), "The MeerKAT view of radio halos in galaxy clusters"

Radio halos are Mpc-scale diffuse synchrotron sources detected in merging galaxy clusters. Their origin is associated with the formation process of the cluster, where part of the merger kinetic energy is dissipated into non-thermal components. In order to recover their extended and low-brightness emission, radio halos have historically been studied at low-resolution. However, MeerKAT exquisite sensitivity to extended emission is now allowing us to study radio halos in unprecedented detail. In this talk, I will report on the detection of substructures in radio halos observed within the context of the MeerKAT Galaxy Clusters Legacy Survey. In particular, I will focus on the detection of surface brightness discontinuities in the radio halo emission. These edges are remarkably similar to those commonly observed in X-rays for shocks and cold fronts in the intra-cluster medium (ICM) of merging clusters. By using the Bullet Cluster as an example, I will show that radio and X-ray edges are correlated. These results demonstrate that thermal and non-thermal components are tightly related and that dynamical motions in the ICM shape the radio halo emission. In the future, these kind of radio discontinuities will be customarily detected in halos and radio observations will thus provide a complementary approach to X-rays to efficiently detect shocks and cold fronts in the ICM.