Top: flux density profiles along PA =  −80° at 8.4 GHz (gray) and 22.3 GHz “extended model” (blue, a)) and “compact model” (green, b)). Bottom: spectral index along PA =  −80°. Displayed uncertainties correspond to a conservative estimate of absolute calibration uncertainties and on-source errors of ~20%. The spectral index distribution of the “extended model” is in light blue, the “compact model” is shown in light green.