Distribution in () plane for the RV (upper panels) and the RGB (lower panels) samples, computed using AGAMA for four different gravitational potentials. Both datasets show diagonal ridges, but the RGB sample extends farther into the outer disc. Beyond 1.42 L_Z, ⊙ the density falls off sharply, which makes it harder to distinguish features. The black curves mark the expected OLR of the bar at 1.08 L_Z, ⊙ and the Cepheid gap at 1.42 L_Z, ⊙.