Mass distribution of identified clumps in G345.5+1.0, plotted as dN/dlog (M/M_⊙) versus mass, where dN/dlog (M/M_⊙) is approximated by the number of clumps ΔN within a logarithmic mass interval Δlog (M/M_⊙). Here, Δlog (M/M_⊙) is constant,  ~0.44. Error bars are estimated by . The arrow shows the clump mass limit,  ~2.9 M_⊙. The continuous line represents the mass distribution fit with dN/dlog (M/M_⊙) ∝ M^1 − α, where the spectral mass index α is 1.7 ± 0.1 for masses between  ~10 and 1.3 × 10³ M_⊙. The dashed line displays the spectral mass index for the stellar initial mass function (IMF) of the solar neighborhood for stellar masses greater than 0.5 M_⊙ (e.g. Kroupa 2002); the line is forced to pass through the peak of the clump mass distribution.