Oral Presentation

Turbulence-Regulated Fragmentation in Molecular Clouds: Linking Cloud-Scale Dynamics to Dense Structure in CHIMPS2

Author(s): Raffaele Rani (NTHU)

Presenter: Raffaele Rani (NTHU)

Understanding how turbulence regulates the formation of dense structures within molecular clouds is key to connecting galactic environment to star formation. While cloud-scale turbulent properties have been widely studied, large-sample statistical studies of their direct impact on internal fragmentation and star-forming substructures remain largely unexplored.

Using the CO Heterodyne Inner Milky Way Plane Survey 2 (CHIMPS2) of the Inner Galactic Plane, we combine a large, uniform catalogue of molecular clouds (5242) identified in $^{13}$CO($J = 3 \rightarrow 2$) with their associated dense substructures (clumps and cores; 17,328 sources), extracted via dendrogram-based segmentation. This enables a statistical comparison between global cloud properties—such as mass, velocity dispersion, and turbulent state—and the population of embedded dense structures.

We investigate how the number, size, and physical properties of clumps and cores vary as a function of cloud-scale turbulence, and explore whether more compressive environments are associated with enhanced fragmentation and star formation activity. In particular, we test whether variations in the turbulence mode (solenoidal versus compressive) are reflected in the abundance, physical properties, and evolutionary state of dense substructures within molecular clouds.

This work provides a new observational framework to link turbulence, cloud structure, and star formation efficiency across a wide range of Galactic environments. By combining CHIMPS2 with complementary infrared surveys, we will characterise the evolutionary state of dense substructures and assess how cloud-scale turbulence relates to their star-forming activity, offering new constraints on models of turbulence-regulated star formation.