Correlation between X(e⁻)and ζ₂ obtained from the 2D maps (line-of-sight averages) for models ℋ (outermost color scale) and ℒ (innermost color scale), combining different time snapshots (t = 30.7, 95.0, and 153.3 kyr). The solid and dashed lines correspond to power-law fits. The cross located at log₁₀(ζ_c) = −16.6 represents the median of the electron abundance (X(e⁻)) for the ℒ model, and the error bars are the 1σ of the data.