Overview of density structures in a vertical cut through the non-circled star-symbol along the y = 0-axis in Fig. 3 for the nominal simulation run C1. The red circle marks the approximate Hill sphere. An approximate boundary of the CPD is the vertically integrated optical thin–thick transition, marked as τ = 1. Features arelabelled identically to the temperature plot (below) with letters as follows: classical spiral arm (a), midplane free-fall region (b), (midplane) accretion shock into the CPD (c), CPD spiral arm (d), vertical accretion shock (e), and accretion funnel from colliding flows (f).