What interaction primarily sculpts the intricate shapes seen in planetary nebulae?

Answer

The collision between the fast wind from the core and the previously ejected slow wind material

When the much faster wind (exceeding 1,000 km/s) catches up to the previously ejected, slower-moving material, the resulting shocks and compression waves sculpt the features seen in the nebula.

What interaction primarily sculpts the intricate shapes seen in planetary nebulae?
forcestarstellar evolutionastrophysicsplanetary nebula