Toomre diagram for RAVE stars and their simulation with the Besançon Galaxy model. RAVE stars with quality control cuts (see Sect. 2) are shown in gray dots. ω Centauri is shown with the green symbol. Isocontours refers to thin-disk (green), young thick-disk (black dashed), old thick-disk (magenta) and halo (cyan) simulated RAVE stars. Orange symbols (8 stars) with error bars correspond to RAVE stars that have a high probability of encountering ω Centauri and relative velocity V_rel< 200 km s^-1 (see Sect. 5), and red dots (314 stars) correspond to halo stars having a negligible probability (<0.01%) of encountering ω Centauri (see Sect. 4). The vertical dashed line indicates zero Galactic rotation. (A color version of this figure is available in the online journal.)