Number density maps for the three models β4, β6, and PE (columns from left to right). In the top row, streamlines represent the velocity structure, and their colour represents the speed. Dashed white lines are column density contours for the values (from top to bottom) 10²⁰, 10²¹, 10²², and 2.5 · 10²² cm⁻². In the bottom row, dashed white lines are density contours for the values (from top to bottom) 10⁶, 5 · 10⁶, 10⁷, and 5 · 10⁷ cm⁻³.