Morphological Analysis of Dense ¹³CO&C¹⁸O Structure in the Milky Way Imaging Scroll Painting (10°≤l≤20°)

Dense molecular clumps are the sites of star formation, and their morphological characteristics are closely linked to the physical properties of the molecular gas. This study is based on data obtained with the Purple Mountain Observatory Delingha (PMODLH) 13.7 m telescope, covering the region with galactic longitudes (l) 10^\circ \leq l \leq 20° and galactic latitudes (b) |b| \leq 5°.25. We focus on the classification and morphological analysis of dense structures traced by ¹³CO (J=1−0) & C¹⁸O (J=1−0) emission lines. Using the FacetClumps algorithm, we detected molecular cores traced by the C¹⁸O spectral line data and manually verified them, resulting in a sample of 544 C¹⁸O cores. Approximately 5.97\% of the ¹³CO clumps in this region contain C¹⁸O cores. We categorized the ¹³CO clumps based on the presence or absence of C¹⁸O cores and found that those containing C¹⁸O cores have significantly higher peak intensities, fluxes, and angular areas compared to those without C¹⁸O cores. However, no significant differences in eccentricity or form factor were found between the two categories. Furthermore, a comparative analysis of form factor shows that the velocity-integrated intensity contours of C¹⁸O cores are notably closer to circular shapes than those of ¹³CO clumps.