The same as Figure 2, but zooming into 50 < x/(c/ω_pe) < 350 and the magnetic field is Lorentz-transformed to the upstream rest frame, where V₀ is the bulk velocity of the upstream plasma in the simulation frame, and ﹩{B}_{z}^{\prime} ={B}_{z}﹩ is conserved. All quantities are smoothed in 1 c/ω_pe, and the color range is tuned to make the upstream structure clear. Note that the magnetic field in the low-density region is saturated.