Radio view of the Peanut cluster: merger-induced stripping and a radio halo shortly after pericentric passage

The Peanut galaxy cluster (SRGe CL0238.3+2005) offers a rare opportunity to investigate thermal and nonthermal processes only ~0.1\,Gyr after pericentric passage. We present a multi-frequency radio study of this system at $z=0.42$ using new MeerKAT and uGMRT observations, complemented by Chandra and MUSTANG-2 data. We identify two morphologically and spectrally distinct radio components: a double-lobed source in the northern subcluster and extended diffuse emission across the cluster center. The double-lobed source has a strongly curved, ultra-steep spectrum and is offset by ~22\,kpc from the nearest brightest cluster galaxy. Its spectral curvature and positional offset are consistent with remnant AGN plasma that may have been displaced during the merger or reshaped by a shock. The diffuse emission extends over ~1~Mpc and is classified as an ultra-steep spectrum (α=-1.77±0.11 between 400\,MHz and 1.28\,GHz) radio halo. Its volume-averaged radio emissivity, (1.1±0.1)×10⁻⁴¹ erg s⁻¹ cm⁻³ Hz⁻¹ at 1.4\,GHz, is an order of magnitude higher than the characteristic value for other halos. The radial profile of the halo is well described by a single exponential fit and its radio emission correlates tightly with the X-ray, with a best-fit slope of 1.11±0.05. Chandra and MUSTANG-2 observations reveal candidate surface brightness discontinuities, with the most prominent inner feature coinciding with a region of flatter spectral index, potentially tracing localized particle (re)-acceleration. The coexistence of an extended ultra-steep spectrum radio halo, high radio emissivity, remnant AGN plasma, and candidate X-ray/SZ discontinuities makes the Peanut cluster an important test case for understanding the evolution of diffuse radio emission and its connection to the dynamical state of the intracluster medium in early-stage mergers.