Comparison of RADEX models with the HF observation. While green curve shows the HF observation, orange curve show the RADEX model we created with the temperature taken from Tauber et al. (1994). Red curve shows a second RADEX model where we use the temperature calculated by Meudon code. We run these models with the same input parameters except for the temperature to figure out the relative importance of the temperature. The temperature is warmer thanthe model predict in the deep cloud. Since we are unable extract the temperature profile near the surface from ¹²CO observations because CO is not formed, we have only focused on the decreasing profile of HF between A_v = 1.2−5.8, that is, gray-shaded region, for this comparison. The rest does not reflect proper calculation. See the text for detailed discussion.