Fraction of stars in multiple systems over the velocity dispersion of stars in the z-direction at the end of the simulation (T = 300 Myr) for the main model. The points are colour-coded according to the angular distance in degrees of the cylinder from the SC with respect to the Galactic centre. Positive values of ϕ_SC indicate the stellar populations in the leading T1 and T2 tails, while ϕ_SC < 0 indicate the trailing tail ones.