X-ray ionization rate ζ_X for the 2D disk structure. Top panel: model with only gas absorption. Bottom panel: model with gas absorption and scattering. The white solid contour line shows N_{⟨ H ⟩ ,rad} = 2 × 10²⁴ cm^-2, which corresponds roughly to the X-ray scattering surface. Below this surface ζ_X starts to be dominated by scattered X-ray photons. The white and red dashed lines show N_{⟨ H ⟩ ,ver} = 2 × 10²² cm^-2 and N_{⟨ H ⟩ ,ver} = 2 × 10²⁴ cm^-2, respectively.