Optical depth τ_WCR(43   GHz) of the WCR as a function of impact parameter r (left panels), and the predicted flux density S_ν at radio frequencies (right panels) for the models of Table 1. In top panels, the dot-dashed, solid and dotted lines represent the optical depth and the radio spectrum from the models B1, B2, and B3, respectively. In bottom panels, the corresponding values of models B2, B4, and B5 are shown by the solid, dot-dashed, and dotted lines, respectively. The physical description of the plots are given in the text.