Evolution of the internal structure of the mass-dominating particles, for the perfect sticking models at 5 AU, for the models with and without non-collisional compaction mechanisms. Aggregates start out as monomers in the top left corner, and grow towards larger sizes and porosities. Lines show individual simulations. Open symbols correspond to points where the mass dominating particles reach a = λ_mfp (°); t_s = t_η (◇); Ωt_s = α (▿); and Ωt_s = 1 (□). Filled symbols show peak mass and filling factor at the times of first: collisional compaction (⋆); gas-pressure compaction (◆); and self-gravity compaction (•).