The evolution of 3C 306 in the galaxy cluster RXCJ1454.4+1622: linking spectral ageing, ICM conditions, and jet dynamics through MHD simulations

Abstract

We present a methodology for analysing radio sources in galaxy clusters by combining multi-frequency radio observations, X-ray analysis of the intracluster medium (ICM), and three-dimensional magnetohydrodynamic (MHD) simulations, and apply it to the galaxy cluster RXCJ1454.4+1622 and its associated FR II radio galaxy 3C 306 (IC 4516). The radio emission exhibits a curved structure connecting the lobes, likely indicating a complex dynamical evolution influenced by environmental effects. Spectral index and break-frequency maps reveal a relatively homogeneous radiative ageing distribution, with characteristic spectral ages of $\sim220$ Myr and a smooth spatial gradient. From equipartition arguments, we estimate an equivalent jet magnetic field of $2.1 \pm 0.3\,μ$G, consistent with values observed in FR II radio galaxies. These observational constraints are used to initialise non-relativistic MHD simulations exploring three scenarios: jet precession, bulk motion of the source through the ICM, and a combined model including both effects. Neither pure precession nor pure source motion alone fully reproduces the observed morphology, whereas the combined model provides a more consistent representation of the jet curvature and lobe asymmetries. Nevertheless, the simulations indicate that source motion is the dominant mechanism shaping the large-scale radio morphology, with jet precession playing a secondary role. The inferred source velocity ($\sim280$ km s$^{-1}$) and precession timescale ($\sim250$ Myr) are compatible with the spectral ageing constraints. These results suggest that the morphology of 3C 306 is influenced by the interplay between jet precession and dynamical interaction with the ICM, highlighting the role of environmental effects in radio-galaxy evolution in clusters.