Wake density evolution compared to the BH and gas velocity evolution for the Run0 simulation. The gas density is measured in a cylinder of 2 pc radius and 20 pc length just behind the BH, oriented along the BH velocity vector. In the measure of the gas effective velocity the gas within a sphere of radius 5 pc around the BH is excluded. The black dashed lines show the first BH output, 5 Myr after its injection and the last output in the supersonic regime respectively. In the supersonic regime density in the wake grows slowly and steadily, whereas, in the transonic regime, the density keeps increasing, but with large oscillations.