Results of spectral aging analysis for the outer structure of 3C 219 presented with color maps, with color bars representing scales given next to each panel. In each panel, a 4.89 GHz contour map is overlaid for reference. The contour levels are (3, 39, 267, 600, 1830)×0.17 mJy/b.a.. The size of the circular beams for the color and contour maps is 20″. Top left: Spectral age map. The gray line marks a section through the source, the results of which are presented in Fig. 8Top right: χ_red² map. Regions with χ_red² > 2.8 (99% confidence level) are marked in red. Bottom left: Upper error map of the spectral age. Bottom right: Lower error map of the spectral age.