Snapshot of the density wave propagating in the distance R ≈ 55R_eq in the converging 2D model of the isothermal outflowing disk (cf. the disk-forming density wave in 1D models in Kurfürst et al. 2014), calculated in the R-z (R-θ) plane. The elapsed time since the start of the simulation is approximately 80 days. The parameters of the critically rotating B0-type parent star are introduced in Table 1. The sonic point is beyond the displayed domain (R_s ≈ 5.5 × 10² R_eq). The model is calculated using the flaring grid whose prescription is given in Appendix A. The initial disk midplane density is determined by the stellar mass-loss rate Ṁ = 10⁻⁹ M_⊙ yr⁻¹ and the viscosity is parameterized as α = α₀ = 0.025 (Penna et al. 2013).