Median candidate prestellar core mass plotted against background cloud column density (A_V units) is shown by the black triangles. The error bars represent the inter-quartile range of observed masses within each bin. The green dashed line depicts a linear fit to the median masses as a function of A_V,bg, given by M_med ∝ (0.2 ± 0.02) × A_V,bg. The blue dash-dotted line corresponds to a linear fit to the upper quartiles of median observed masses, while the magenta dotted line represents a linear fit to the lower quartiles.