Simulation results for the disk gap at 10 au and δ = 10⁻⁴, where M_G ≈ 3 × 10⁻³M_⊕. (a) Radial profiles in one of the five simulations of the dust and gas surface densities as well as the dust-to-gas ratio at t₀ when planetesimal formation starts, (b) Pebble flux and the pressure support parameter η around the pressure bump from one of the five simulations, where the dashed lines denote negative values, (c) Time sequence of mass m and semi-major axis r of the planetesimals. Planetesimals that reach 10⁻² M_⊕ by the end are denoted with large dots. Each colour shows one of the five simulations, which ended from t₀ + 2.2 × 10⁴ to t₀ + 3.4 × 10⁴ yr. Further descriptions are provided in the text.