Logarithmic grid maps (in the common logarithmic space of log₁₀) showing the X-conversion factors using the [CI] (1–0) (top) and the CO (1−0) (bottom), defined as the ratio of the PDF-averaged H₂ column density to the PDF-averaged brightness temperature multiplied by the line width. These panels show results of the A_V-PDF of m = 5 mag and σ_PDF = 0.4, corresponding to $\overline{A_{\mathrm{V}}}=5.42$ mag. Each column corresponds to different [O/H] ratios (left to right: −1.0 to 0.2 at a step of 0.2; see also Table 1 and Fig. 1). In all panels, the x-axis is the cosmic-ray ionization rate in the range of ζ_CR = 10⁻¹⁷−10⁻¹³ s⁻¹, and the y-axis is the FUV intensity in the range of χ/χ₀ = 10⁻¹−10³. The HI-to-H₂ transition at which the condition HI = 2H₂ is satisfied is shown as the solid red line. For ζ_CR−χ/χ₀ pairs smaller than those corresponding to the red line, the distribution is molecular (H₂ rich; colored partition), and otherwise, it is atomic (HI rich; white partition). For [O/H] = 0.0 and 0.2, the distribution is H₂ rich for the entire range of ζ_CR and χ/χ₀ we explored. The color bar shows the logarithm of the X-factor.