Top panel: difference in the PM values for the Galactic longitude coordinate, |$\Delta \mu _{l} \cos b$|⁠, against the extinction |$A_{K_{\rm s}}^{\rm IRAC}$|⁠. Bottom panel: Same as top panel, but for the PM difference in the Galactic latitude coordinate, |$\Delta \mu _{b}$|⁠. The horizontal black line is located at |$\Delta \mu = 0$| in each Galactic coordinate. Purple dots show the mean PM difference in bind of 0.05 |$A_{K_{\rm s}}^{\rm IRAC}$|⁠.