X-ray and Radio Observations of the Radio Relic Galaxy Clusters 1RXS J0603.3+4214 and RXC J1053.7+5453

Motokazu Takizawa

doi:10.3390/galaxies7010002

Abstract

We study two galaxy clusters with radio relics, 1RXS J0603.3+4214 and RXC J1053.7+5453, through X-ray and radio observations. Radio relics are diffuse non-thermal radio sources found in outskirts of galaxy clusters. Because of their shape and location, they are thought to be related to cluster merger shocks. The galaxy cluster 1RXS J0603.3+4214 has a well-known linear-shape “toothbrush” radio relic. We investigate the temperature structure across the relic to constrain the Mach number of the associated shock. The results are compared with radio spectral results, which suggest that a simple diffusive shock acceleration model does not hold for this relic. The RXC J1053.7+5453 harbors a standard arc-like relic. We also get the Mach number from the temperature profile. In addition, we found an edge-like structure in the X-ray image between the X-ray peak and relic. We investigate the density and temperature profiles across the edge and found that the structure is likely relevant to not a shock but a contact discontinuity.

Highlights

Some merging galaxy clusters have diffuse non-thermal radio emitting regions, which indicates that there are non-thermal electrons with GeV energy and magnetic fields of a μG level in the intracluster medium (ICM) [1,2,3]. These radio-emitting regions are often classified into three categories: radio halos, radio mini halos, and radio relics, depending upon their locations, morphology, and sizes
We present here the X-ray and radio results of two galaxy clusters with radio relics, 1RXS J0603.3+4214 and RXC J1053.7+5453
J1053.7+5453, we measured the ICM temperature for the first time and estimated the Mach number of the possible shock associated with the relic

Summary

Introduction

Some merging galaxy clusters have diffuse non-thermal radio emitting regions, which indicates that there are non-thermal electrons with GeV energy and magnetic fields of a μG level in the intracluster medium (ICM) [1,2,3]. We can estimate the Mach number (MX ) from the temperature and/or density jumps of the ICM across the shock, which can be obtained from the X-ray observations. Surface brightness analyses of Chandra X-ray data indicate that the shock is just at the outer edge of the relic and that its Mach number is lower (MX < 1.5) than the value estimated from the radio data [9], though former XMM results show that the shock is shifted outward from the relic outer edge [11] We observed this cluster by Suzaku in October 2012. “toothbrush” relic from [6]

The temperature profile the 1RXS

The RXC

Conclusions