Aitoff projection of all particles in the simulation seen from the position of the Sun in the Galactic coordinate system. TheM 31 particles are shown in green. The particles belonging to MW and farther than 50 kpc from the MW disk plane are plotted in red. The other MW particles are shown in blue. The arrows show the proper motions of the red particles as observed from the Sun in the simulation. This figure can be compared to Fig. 1 of Pawlowski et al. (2015b).