Three-dimensional simulations with the code RING. We show the projected shell column density at 60 kyr after the formation of the shell. The SN explodes at r_GC = 5 pc and θ_GC = 0° (top), 70° (middle), 90° (bottom) in an ambient medium of density n_out = 10⁴ cm⁻³, with M_SMBH = 4 × 10⁶ M_⊙ and the NSC as given in Sect. 2. The color bar gives the projected density in units of cm⁻². The meshed region shows the central region with a radius of 1 pc. The dashed line shows the reference circle with a radius of 5 pc and the cross gives the original position of the SN explosion.