H₂ column density (left), dust temperature (centre) maps, and dust temperature histogram of the map pixels with A_V > 3 mag (right) of the NGC 1333 star-forming region surrounding IRAS 2A as observed with the Herschel Space Observatory by the Gould Belt survey (André et al. 2010). The black contour in the maps depicts the 3 mag level. The red curve in the histogram depicts the Gaussian fit of the histogram around the histogram peak.