Lagrangian radii containing 50, 75, 90, 95, and 99% (from bottom, r₅₀, to top, r₉₉) of the stars in 15 degree wide bins of position angle about the disk center (marked with a cross) at t_sim = 626 Myr (to match Fig 1). Upper panel: TI-fid model, with an overplot of the Lagrangian radii on an x-y plot of the young (upper left subpanel) and intermediate-age (lower left subpanel) stars, with gray fill showing the extent of the disk gas, and right subpanel; showing the Lagrangian radii as a function of position angle for the young (blue) and intermediate-age stars (red). Position angles are measured anticlockwise (as indicated by the black arrow) from the horizontal line along the x-axis. Lower panel: Same as for the upper panel except for the RP-fid model.