Mass-radius relationship. Filled red traingles indicate 870 μm clumps with candidate YSOs projected inside the limits determined by Gaussclumps, while green open triangles indicate 870 μm starless clumps. Magenta open squares indicate the 250 μm clumps. The blue solid line shows the scaled mass-radius threshold for high-mass star formation determined by Kauffmann & Pillai (2010). The rescaled mass-radius relationship derived by Urquhart et al. (2013) is shown by the dotted black line. Upper and lower solid red lines show surface densities of 1 g cm^-2 and 0.024 g cm^-2, respectively. Dotted green lines indicate volume densities at 10³ cm^-3, 10⁴ cm^-3, 10⁵ cm^-3 , and 10⁶ cm^-3.