摘要：Our location in the Milky Way provides an exceptional opportunity to gain insight on the galactic evolution processes, and complement the information inferred from observations of external galaxies. Since the Milky Way is a barred galaxy, the study of motions of individual stars in the bulge and disc is useful to understand the role of the bar. TheGaiamission enables such study by providing the most precise parallaxes and proper motions to date. In this theoretical work, we explore the effects of the bar on the distribution of higher-order moments – the skewness and kurtosis – of the proper motions by confronting two simulated galaxies, one with a bar and one nearly axisymmetric, with observations from the latestGaiadata release (GaiaDR2). We introduce the codeASGAIAto account for observational errors ofGaiain the kinematical structures predicted by the numerical models. As a result, we find clear imprints of the bar in the skewness distribution of the longitudinal proper motionμℓinGaiaDR2, as well as other features predicted for the nextGaiadata releases.
关键词：enGalaxy: structureGalaxy: evolutionGalaxy: kinematics and dynamicsmethods: numerical
