Cumulative probability distributions (CDFs) of τ_eff at redshift, z = 5.4 for a variety of parameter values. The left panel shows the variation of CDF for different mean photoionization rate (in 10⁻¹²/s, i.e., $⟨{\mathrm{\Gamma }}_{12}^{\mathrm{HI}}⟩$). The middle panel shows the CDF variation with effective mean free path (λ₀ in h⁻¹cMpc). The right panel shows the CDF variation with different reionization temperature increment (T_re).