Journal ArticleHST proper motions on the far side of the Galactic bar—dataSoto, Mario; Kuijken, Konrad; Rich, R Michael; Clarkson, William I; Nilo Castellón, José Luis; Fernández-Trincado, José G; Contreras Ramos, Rodrigo; Kunder, Andrea; Baravalle, Laura D; Alonso, M Victoria; Simion, Iulia T; Johnson, Christian I; Vieira, KatherineABSTRACT This is the third paper in a series that attempts to observe a clear signature of the Galactic bar/bulge using kinematic observations of the bulge stellar populations in low foreground extinction windows. We report on the detection of ∼100 000 new proper motions in four fields covering the far side of the Galactic bar/bulge, at negative longitudes. Our proper motions have been obtained using observations from the Advance Camera for Surveys (ACS), on board of the Hubble Space Telescope (HST), with a time-baseline of 8–9 years, which has produced accuracies better than 0.5 mas yr−1 for a significant fraction of the stellar populations with F814W < 23 mag. Interestingly, as shown in previous works, the Hess diagrams show a strikingly similar proper motion distribution to fields closer to the Galactic center and consistent with an old stellar population. The observed kinematics point to a significant bulge rotation, which seems to predominate even in fields as far as l ≃ −8°, and is also reflected in the changes of the velocity ellipsoid in the l, b plane as a function of distance.2023-07-0410455964Monthly Notices of the Royal Astronomical Society5241224 to 2340035-8711https://doi.org/10.1093/mnras/stad19112009836National Science Foundation