2D axis-aligned slices at Y = 0 through the 3D computational domain showing colour-coded (from top to bottom) the atomic hydrogen number density, temperature, and number densities of the radioisotopes ²⁶Al, ⁵³Mn, ⁶⁰Fe, and ²⁴⁴Pu in the LB region at different times in the past, as extracted from our fiducial simulation. The overplotted symbols represent for the respective time the projected positions of the Sun (empty circle) and of the SN progenitor stars that have not exploded by then (filled circles). Projected trajectories are shown as thin solid lines. The inlay in the first-column panels shows a magnification of the boxed area with side length 100 pc.