Vertical acceleration of dark matter (top panels) and gas (bottom panels). Black dot-dashed circles are situated at 20 kpc, illustrating the size of the stellar disk of the galaxy. The dark matter acceleration in the top three leftmost panels is dominated by the crossing of dark matter subhalos DM1119 and DM2595. The effect of gas at these times (bottom panels) is bimodal. The dark matter a_Z of the right block of panels is dominated by the satellite galaxy “Escarabajo”, which applies positive a_Z in the positive x – positive y region of the mesh.