For Runs 1–3 (left to right), solar wind H⁺ test particle traces (injected near the front wall with v_i =U_e) and M_ms = 2 colored with the Y coordinate, i.e. the off-plane distance. The magnetosonic Mach numbers calculated separately for electron bulk fluid velocity U_e (magenta) and center-of-mass velocity v_tot (orange; holes in this contour are artifacts from visualization at grid refinenent interfaces) are shown at the M_ms = 2 contour, andfor the solar wind proton bulk velocity as background color on the XZ plane. The proton Mach number color scale is chosen so that M_ms = 2 is noted by white and true subsonic flow M_ms ≤ 1 by yellow to pink for a decreasing Mach number. For Run 1, is larger than 2 almost everywhere. The apparent lack of an SW cavity for Runs 2 and 3 is due to particles moving into and out of the plane of view. This is shown by the color of the traces.