2025ApJ...994..118M

We study the structure, kinematics, and star-forming activity of filamentary cloud F-NE associated with AGAL323.444+0.096 using ¹³CO (J = 2-1) molecular line and continuum data from the far-infrared to near-infrared. The cloud comprises two elongated subfilaments, F-NE-north and F-NE-south, each spanning 25 pc, with systemic velocities of -65.25 and -67.38 km s^–1, respectively. F-NE-north and F-NE-south seem to be merging by collision. They exhibit signatures of cloud-cloud collisions, including U-shaped and arc-like morphologies, complementary components, and bridge features, suggesting ongoing collisions. The interacting zones show enhanced column densities and elevated velocity dispersion, further supporting the collision scenario. All these features are consistent with the “fray and gather” model. Dense clumps and young stellar objects are predominantly concentrated in these collision regions, implying that filament merging and localized collisions drive the formation of massive dusty clumps capable of nurturing massive stars. These results demonstrate that filament merging by collision is crucial for both filament structural evolution and the formation of massive stars and clusters.