Example of a 3D trajectory of a plume rising above the disk according to Eqs. 1 and 2 and integrated over 140 Myr. Only one side of the plume is shown. The black circle depicts a circle in the disk plane with a radius of ∼5 kpc. The blue line corresponds to case (a), namely the source of the plume moves together with the gas and stars in the disk plane. The red curve is case (b), when the source of the plume, i.e., an area of active star formation, moves relative to the gas. At this distance from the GC, the difference between these two cases is not large.