Radio ghosts: Radio polarimetry study of newly discovered cluster minihalo candidates or radio tailed galaxies

Extended diffuse radio emission in the central regions of galaxy clusters is commonly associated with non-thermal processes in the intracluster medium (ICM), but its origin and the mechanisms responsible for sustaining it remain uncertain. We present the discovery and multi-wavelength analysis of two diffuse radio sources, MKTJ0355-4237 and MKTJ0355-4230, to assess their nature and investigate their radio spectral and magnetic field properties through radio polarimetric analysis. We use deep MeerKAT L-band (1.28 GHz) observations to perform spectral analysis of the diffuse emission and study its polarisation properties via rotation measure synthesis. These are complemented by eROSITA X-ray data and DESI photometric redshift catalogues to characterise the host cluster environments. MKTJ0355-4237 is confirmed as cluster-scale minihalo with extent of about 400 kpc, while the other diffuse source MKTJ0355-4230 remain uncertain and could be either associated with a radio minihalo or radio tailed galaxy. Both show steep spectra (α about-0.7 to-0.8) that steepen toward the outskirts (α-2.5), consistent with spatial variations in electron ageing and re-acceleration. Polarised emission is detected in both systems, with fractional polarisation about1,% in the centres and increasing in the outer regions of MKTJ0355-4237. MKTJ0355-4230 is associated with a previously uncatalogued cluster and shows an X-ray morphology offset from the brightest cluster galaxy, indicative of dynamical activity. MKTJ0355-4237 exhibits a sharply bounded internal radio deficit without a corresponding X-ray counterpart, within current sensitivity limits. The spectral steepening supports turbulent re-acceleration as the origin of the diffuse emission.