Snapshots of the synchrotron emission maps of the jet before and after introduction of the ejecta, seen at two frequencies, ν = 10¹⁰ Hz (top) and ν = 10¹⁸ Hz (bottom). Each map represents the flux intensity in mJy units. The R and the Z axes are given in R_jet units. These maps represent the flux in the comoving frame for a viewing angle of θ_obs = 90° at three different comoving times (see the white boxes). The flux is evaluated at the distance of the radio galaxy 3C 111.