The dust temperature and ISRF in Hi-GAL SDP fields
The Herschel infrared Galactic Plane Survey (Hi-GAL) maps our inner galaxy in 5 bands between 70 micron and 500 micron. And the thermal dust emission peak at far-infrared (FIR) wave range. We calculate spectral energy distributions (SEDs) of dust FIR emission using CLOUDY code. The pre-calculated SEDs were then used to minimize the chi-square between the observation and model prediction. Then we get the best estimate of hardness of the interstellar radiation field (ISRF) and the temperature of dust grains.