Morphological Comparison of Three Algorithms for ¹³CO Clump Detection in the Milky Way Imaging Scroll Painting

The objective evaluation of molecular clump detection algorithms is pivotal for unraveling the hierarchical structure of the interstellar medium and for revealing the physical processes that drive star formation. However, systematic comparisons of morphological differences and structural characterization capabilities among algorithms applied to real observational data are still lacking. We apply FellWalker, FacetClumps, and Dendrograms to ¹³CO (J=1-0) spectral data from three representative regions of the Milky Way Imaging Scroll Painting (MWISP): 15.25^\circ\leq l\leq18.25^\circ,\; 0^\circ\leq b\leq 1.5^\circ; 100^\circ\leq l\leq110^\circ;\;|b|\leq5.25^\circ; and 180^\circ\leq l\leq190^\circ,\;|b|\leq5.25^\circ. Using RJ-plots to classify the morphologies of ¹³CO clumps, we find that FacetClumps identifies a substantially higher fraction of centrally overdense, quasi-circular clumps in all three regions (all exceeding 85%), whereas FellWalker and Dendrograms detect a larger share of elongated structures, ranging from 20% to 40% of the detected clumps. A comparison based on C¹⁸O counterpart statistics in the M16 field shows that the centrally overdense, quasi-circular ¹³CO clumps found by FellWalker and FacetClumps contain C¹⁸O counterparts at rates of 77% and 91%, respectively. We further compute H_2 column densities for the ¹³CO clumps and examine their relation to compactness. We find that clumps with higher column densities tend to be more compact, and high-column-density ¹³CO clumps are more likely to have associated C¹⁸O counterparts.