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We revisit the stellar velocity distribution in the Galactic bulge/bar regionwith APOGEE DR16 and {\it Gaia} DR2, focusing in particular on the possiblehigh-velocity (HV) peaks and their physical origin. We fit the velocitydistributions with two different models, namely with Gauss-Hermite polynomialand Gaussian mixture model (GMM). The result of the fit using Gauss-Hermitepolynomials reveals a positive correlation between the mean velocity($\bar{V}$) and the "skewness" ($h_{3}$) of the velocity distribution, possiblycaused by the Galactic bar. The $n=2$ GMM fitting reveals a symmetriclongitudinal trend of $|\mu_{2}|$ and $\sigma_{2}$ (the mean velocity and thestandard deviation of the secondary component), which is inconsistent to the$x_{2}$ orbital family predictions. Cold secondary peaks could be seen at$|l|\sim6^\circ$. However, with the additional tangential information from {\itGaia}, we find that the HV stars in the bulge show similar patterns in theradial-tangential velocity distribution ($V_{\rm R}-V_{\rm T}$), regardless ofthe existence of a distinct cold HV peak. The observed $V_{\rm R}-V_{\rm T}$(or $V_{\rm GSR}-\mu_{l}$) distributions are consistent with the predictions ofa simple MW bar model. The chemical abundances and ages inferred from ASPCAPand CANNON suggest that the HV stars in the bulge/bar are generally as old as,if not older than, the other stars in the bulge/bar region.

Understanding the velocity distribution of the Galactic Bulge with APOGEE and Gaia