NH₃ (1,1) and (2,2) line width, gas pressure ratio, (1,1) main hyperfine component optical depth, kinetic temperature and column density plotted against the mass of the cores calculated from Herschel dust data. The filled points mark the reliable sample, the open points the candidate sample. The grey line indicates a linear fit for the two parameters for the whole sample, the black line for the reliable sample. The Pearson correlation coefficients are noted with the same colours.