Mean dust temperature versus the mean column density of the respective core. Sources are colour-coded by region, with solid filled cores denoting prestellar cores and hollow circles denoting the starless cores. The cross on the figure shows the mean errors for this population of cores. The solid green line shows the relation T = −3.5log₁₀ N(H₂) + 86.0. The dashed grey line is the relation T = −3.7log₁₀ N(H₂) + 15.9 found by Marsh et al. (2016) for cores in Taurus L1495.