Discovery of the correspondence between intra-cluster radio emission and a high pressure region detected through the Sunyaev-Zel'dovich effect

TL;DR

This study uncovers a clear link between diffuse intra-cluster radio emission and a high-pressure region in galaxy cluster RX J1347-1145, suggesting shock-driven electron re-acceleration.

Contribution

First unambiguous detection of the association between radio excess and high-pressure region via Sunyaev-Zel'dovich and X-ray data in a galaxy cluster.

Findings

Radio excess correlates with hot region detected by SZ and X-ray.

Electron re-acceleration likely caused by shock front.

Supports shock-driven models for mini-halo emission.

Abstract

We analyzed new 237 MHz and 614 MHz GMRT data of the most X-ray luminous galaxy cluster, RX J1347-1145. Our radio results are compared with the MUSTANG 90 GHz Sunyaev-Zel'dovich effect map and with re-processed Chandra and XMM-Newton archival data of this cluster. We point out for the first time in an unambiguous way the correspondence between a radio excess in a diffuse intra-cluster radio source and a hot region detected through both Sunyaev-Zel'dovich effect and X-ray observations. Our result indicates that electron re-acceleration in the excess emission of the radio mini-halo at the center of RX J1347-1145 is most likely related to a shock front propagating into the intra-cluster medium.