First row: initial (dashed black), final (solid blue), and net (dash-dotted red) vertical velocity dispersions, σ_z,i, σ_z,f, and Δσ_z, respectively, as functions of the initial radius, r₀, for particles ending up in the green bin at the final time indicated in each panel. Two time periods for each of the three models are shown, as indicated. Migrating stellar samples decrease or increase their velocity dispersion is such a way as to match the value at the destination. Second row: same as the first row, but for the radial velocity dispersion. Third row: the corresponding initial radial distributions of stars ending up in the green bin at the final time indicated in each panel. The bar’s CR and OLR, measured at the final times, are shown by the vertical dotted and solid black lines. Most migrators come from the inner disc, with a strong contribution from particles originating near the bar’s CR.