RADEX non-LTE modeling of the H₂CO line ratios to probe H₂ spatial-density (top) and kinetic temperature (bottom). The background color shows the modeled ratios on the density and temperature grid. Solid lines are the contours of modeled ratios corresponding to the observed values and dashed lines correspond to the uncertainties. Adopted value of column density for these contours is N = 10¹³ cm⁻². The effects of optical depths were monitored during the modeling and they are smaller than 0.3 and hence do not effect the results significantly.