Contributed Talk - Splinter Stars

Wednesday, 15 September 2021, 16:15   (virtual Stars)

Substructures of the molecular clouds: connecting theory and observation

Sara Rezaei Kh., Daniel Seifried, Juan D. Soler
Max Planck Institute for Astronomy (MPIA), University of Cologne, Max Planck Institute for Astronomy (MPIA)

The unprecedented astrometry from the Gaia satellite provides a key data set to study the structure of star-forming regions and its connection to the distribution of young stars. This is accompanied by an ever-growing number of simulations of molecular cloud formation and destruction. In this work, we connect our 3D dust mapping results based on Gaia observations and our numerical simulations concerning the shape of molecular clouds, which are embedded in their Galactic environment and are affected by stellar feedback. We present 3D dust maps for two of the most massive local molecular clouds, Orion A and California. Despite their apparent similarities on the plane of the sky, the first is an active star-forming region, whereas the latter is a much quieter cloud in terms of star formation. Their 3D density structure and young stellar associations can explain this dissimilar behaviour: Orion A is a filamentary structure shaped by stellar feedback. California, on the other hand, is a more sheet-like structure, in an earlier evolutionary stage. To extend this analysis, we compare these observational results with the simulations of molecular clouds in the SILCC-Zoom project. We demonstrate how sheet-like structures can form as a result of feedback from supernova explosions and explore the properties of these structures. We also show how denser filamentary substructures are formed within the sheet through gravitational collapse. Finally, we present synthetic observations of these simulations to explore further what can be learned from the 3D dust mapping of molecular clouds in terms of their density substructure and dynamics.