uGMRT and MeerKAT Observation of RXCJ0232−4420: A Quiet Cluster with a Giant Radio Halo

Abstract Giant radio halos are Mpc-scale extended sources associated with merging clusters, while minihalos are preferentially associated with cool-core clusters. Both trace the intracluster medium (ICM) plasma physical process, and recent low-frequency observations increasingly blur the distinction between the two classes. We present the first multifrequency spectral analysis of the galaxy cluster RXCJ0232–4420, which hosts a cool core, using uGMRT (400 and 650 MHz) and MeerKAT (1283 MHz) observations. The central radio emission extends beyond ∼1 Mpc at all frequencies, confirming it as a giant radio halo. One candidate relic (to the east) has also been detected, with an extent of ∼300 kpc. The integrated spectral indices of the halo and candidate east relic are α = −1.17 ± 0.17 and α = −0.85 ± 0.17, respectively. The resolved spectral map of the halo is mostly uniform (−1.0 to −1.3) and does not show any radial steepening. The radio surface brightness profile is well modelled by a single exponential law, with the e -folding radius constant across frequencies. The radio halo emission is morphologically well correlated with the thermal emission. Point-to-point radio–X-ray correlation analysis gives a sublinear relationship (slope ∼0.80), with no frequency evolution. The presence of Mpc-scale emission in the cool-core cluster shows that such emission can arise in dynamically intermediate systems. Our results demonstrate that merger-driven turbulence, even from minor disturbances, can sustain cluster-wide particle reacceleration without destroying the cool core.