Example of the component separation method for the case of the Hα emission. The left panel is the original Hα image smoothed to the resolution of the SPIRE 500 μm band, the central panel shows the SF regions detected by SExtractor using a threshold of 40, and the right panel corresponds to the diffuse emission. The white contours are included to facilitate the comparison between panels and they correspond to the boundaries of the SF regions. The emission from the SF component represents 41.7% of the total Hα emission.