Zones of pile-up of pebbles and/or silicate dust around the snow line as a function of F_p/g and α_Dz(= α_Dr)∕α_acc (case of a variable Δx_subl; Eq. (74) in Sect. 3.4). The numbers in the parenthesis represent the maximum ρ_p ∕ρ_g (left) and ρ_d∕ρ_g (right) obtained from our full 1D simulations, respectively. The numbers below the parenthesis represent the rock fraction in the surface density of pebbles at the maximum ρ_p ∕ρ_g (when a runaway pile-up of silicate dust occurs, the fraction is not shown because the system would gravitationally collapse to form 100% rocky planetesimals). The runaway pile-up of pebbles (labeled as “Peb-RP”) or that of silicate dust (labeled as “Sil-RP”) occurs around the snow line, depending on the combinations of F_p/g and α_Dz(= α_Dr). The color contour shows an analytical prediction of the maximum ρ_d∕ρ_g just inside the snow line obtained from Paper I. The black dashed line indicates analytically derived critical F_p/g above whichthe “no-drift (ND)” takes place (labeled by “ND” for the results of 1D simulations in the panels) at the outer boundary (r = 5 au and τ_s,p = 0.125; Sect. 4.2). Drift-BKR and Diff-BKR onto the motions of pebbles and silicate dust are included with K = 1. Left and right panels: cases of α_acc = 10⁻² and α_acc = 10⁻³, respectively. In the case of α_acc = 10⁻², the runaway pile-up of silicate dust is inhibited because the required parameter regime is overlapped by the “no-drift” region (i.e., pebbles do not reach the snow line). In the case of α_acc = 10⁻³, the runaway pile-ups of both pebbles and silicate dust occur.