Left panel: spectral index distribution in J 1332–3308 in the frequency range 1.4 GHz–8.4 GHz (colour scale) at a resolution of 4.5′′ × 4.0′′, with 1.4 GHz VLA contours overlaid (resolution 8.9′′ × 4.6′′, contours start at 0.84 mJy b^-1 and scale by a factor of 2). The colour scale is as follows: purple 0.6, orange 1.1, light orange 1.4. Right panel: spectral index distribution in J 1332–3308 in the frequency range 240–610 MHz (colour scale) at a resolution of 18′′ × 12′′, with 240 MHz GMRT contours overlaid (same as Fig. 2, right panel). The colour scale is as follows: orange 0.5–0.6, purple 1, and blue 1.8.