Density profile along the symmetry axis of the jet for cases C, D and E and for the unperturbed atmosphere. All cases show an increased density at the head of the jet beam. The maximal z reach is inversely proportional to the opening angle. Case C (cylindrical case) keeps a near constant density. Cases D and E show a series of nodes with increased density. The position of the nodes depends on the opening angle: the wider the opening angle, the longer the internodal distance. The jet density in case C becomes higher than the ISM density from about z ≈ 12, whereas for the other two cases, it remains below the ISM density profile throughout the domain.