Estimation of the spectral line broadening contribution from the unresolved velocity perturbations (which we denote as turbulence) and temperature perturbations. The Gaussian width corresponding to the thermal broadening contribution (dashed curve) is obtained from the average of temperature for the pixels along the line-of-sight crossing the cylinder. The Gaussian width corresponding to the turbulent broadening contribution (solid lines) is obtained from a Gaussian fit to the sum of multiple Gaussians, one for each pixel in the cylinder along the line-of-sight, with a fixed temporal averaged thermal broadening and shifted centre given by the line-of-sight velocity at that pixel.