Difference in gas temperatures with respect to the fiducial model. White contours (solid lines) are gas temperatures of 300 K and 1000 K. The white dotted lines show the 300 K and 1000 K gas temperatures, and white dashed lines show A_v=1 of the reference model. Since the gas and dust densities are the same for each model, the location of the A_v=1 contour is the same in all panels. The center panel shows the actual gas temperature of the fiducial model, which is the same as panel e of Fig. 2. The text in each panel denotes Δ log₁₀(ɛ_C), Δ log₁₀(ɛ_O), and the C/O ratio.