A combined LOFAR and XMM-Newton analysis of the disturbed cluster PSZ2G113.91-37.01

Abstract

In this work, we investigate the interplay between the X-ray and radio emission of the cluster PSZ2G113.91-37.01 (z = 0.371) using the high-quality XMM-Newton observations of the Cluster HEritage project with XMM-Newton - Mass Assembly and Thermodynamics at the Endpoint of structure formation (CHEX-MATE), and the images from the second data release of the LOFAR Two-meter Sky Survey (LoTSS-DR2). The cluster is undergoing a merger along the north-south axis and shows a central radio halo and two radio relics, one in the southern region and one in the northern one. Analysis of the intracluster medium (ICM) distribution revealed the presence of a northern surface brightness (SB) jump associated with the merger event. By extracting spectra across this discontinuity, we classified the edge as a cold front. Furthermore, we made use of upgraded Giant Metrewave Radio Telescope observations that allowed us to perform a spectral analysis of the G113 radio emission. We found evidence for the re-acceleration of particles in the northern relic, and we measured an associated Mach number of ℳ = 1.95 ± 0.01, as inferred from radio observations. We then performed a point-to-point analysis of the X-ray and radio emission, both in the halo and in the northern relic regions. We found a strong correlation for the halo and an anti-correlation for the relic. The former behaviour is in agreement with previous studies. The relic anti-correlation is likely related to the reverse radial distribution of the X-ray (increasing towards the cluster centre) and radio (decreasing towards the cluster centre) emissions. Finally, we performed a point-to-point analysis of the radio emission and the residuals obtained by subtracting a double β model from the X-ray emission. We found a strong correlation between the two quantities. This behaviour suggests the presence of a connection between the process responsible for the radio emission and the one that leaves fluctuations in the X-ray observations.