Final snapshot of the fiducial run (a = 0.9375); t/t_g = 9000. The magnitude of the outgoing radial mass flux density ﹩\sqrt{-g}\rho {u}^{r}(\gt 0)﹩, where u^r is the radial component of the four-velocity, ﹩\sqrt{-g}={\rm{\Sigma }}\sin \theta ﹩ is the metric determinant, and ﹩{\rm{\Sigma }}\equiv {r}^{2}+{a}^{2}{\cos }^{2}\theta ﹩, is shown with a color-filled contour (the upper computational domain; 0 ≤ θ ≤ π/2). Contours with navy solid lines show ﹩{u}^{r}=0﹩, while “whiteout” regions indicate the magnitude of the ingoing radial mass flux density ﹩\sqrt{-g}\rho {u}^{r}(\lt 0)﹩. The jet stagnation surface is clearly displayed inside the PFD funnel (﹩{u}^{r}=0﹩). −u_t = 1 (Be ≈ 0) is shown with a magenta dashed line. Other components are identical to those in Figure 2.