Radiative age of T1. Top: radiative age map at 30″ obtained by fitting radio images at 50, 143, and 323 MHz with the TJP model (α_inj = 0.51, B₀ = 2.2 μG). Typical errors are ~20 Myr. The sub-regions are indicated by horizontal bars. Bottom: age profile measured in boxes of beam-size width. The boundaries of the sub-regions are indicated with dashed vertical lines. The blue solid line is the result of a linear fit to the data points.