Stacked [O III] profiles for the peaked and non-peaked spectrum sources in the low redshift sample, while controlling for L_1.4 GHz (a−c) and L_[O III] (d−f). The shaded regions show the 1σ errors on the stacked profiles, estimated by stacking 1000 bootstrapped samples. The best-fit model parameters for each profile are summarised in Table C.2. (a)−(c) Stacked profiles for PS and NPS sources while controlling for L_1.4 GHz: (a) 10²³ − 10²⁴ W Hz⁻¹, (b) 10²⁴ − 10²⁵ W Hz⁻¹ and (c) 10²⁵ − 10²⁶ W Hz⁻¹. Stacked profiles for PS and NPS sources while controlling for L_[O III]: (d) 10³⁹ − 10⁴⁰ erg s⁻¹, (e) 10⁴⁰ − 10⁴¹ erg s⁻¹ and (f) 10⁴¹ − 10⁴² erg s⁻¹.