Results of the quadrant analysis on M31. Left-hand panel: results from the quadrant analysis of M31 in the heliocentric frame. In low opacity are shown the inferences obtained for each individual quadrant, while shown clearly are the inferences resulting from the analysis of the 2D space from the right-hand panel. The solid and dashed error bars represent, respectively, the statistical and systematic uncertainties. The black pentagon represents a strictly radial motion in the galactic reference frame. Right-hand panel: example of the 2D PDFs (1, 2 and 3σ) obtained from the quadrant analysis in the direction of the right ascension and their marginalised 1D PDFs.