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| EPoS Contribution |
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Tracing turbulence properties, volume densities and star formation
Jan Orkisz Chalmers, Goeteborg, SE | |
| Star formation in molecular clouds is controlled by many parameters, including gravity, magnetic fields, stellar feedback, etc. The nature of turbulence also plays a key role: compressive motions, as opposed to solenoidal motions, can trigger the collapse of cores, or mark the expansion of Hii regions. The mechanisms that inject kinetic energy are often compressive in nature (self-gravity or feedback), but regardless, star formation remains a highly inefficient process. This raises the question of the importance of compressive motions in molecular clouds. We measure observationally in Orion B how the solenoidal/compressive momentum ratio varies depending on local properties, or with the considered densities traced by different molecular tracers. We also measure how this ratio correlates with the local star formation rate and the dense gas fraction. This shows that compressive motions are dominant only locally around active or future star forming regions. | |
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| Caption: Solenoidal forcing decreases towards the center of an active star- forming region (blue) and a cluster of starless cores (green), localized on the peak volume density map of the Orion B GMC. | |
| Collaborators: J. Kainulainen, Chalmers, FR J. Pety, IRAM, FR M. Gerin, ObsPM, FR E. Olivier, ENS, FR F. Levrier, ENS, FR A. Spilker, Chalmers, SE et al. |
Key publication
Suggested Session: Molecular Clouds |