Allowed values of the jet viewing angle (θ) and its bulk velocity (v_bulk) in units of the speed of light (β_bulk = v_bulk/c). The hatched orange area corresponds to the allowed parameter space in the β − θ plane using the ratio of jet to counter-jet brightness, and the magenta area traces the parameter space allowed by the correlation of Giovannini et al. (1988), as explained in Sect. 3.3. The dashed black line corresponds to 1/Γ, which is the typical value to discern between aligned (< 1/Γ) and misaligned (> 1/Γ) AGN.