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| EPoS Contribution |
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Multi-scale dynamics in star-forming regions: the interplay between gravity and turbulence
Alessio Traficante INAF-IAPS, Rome, IT | |
| In the multi-scale view of the star formation process the material flows from large molecular clouds down to clumps and cores. In this paradigm it is still unclear if it is gravity or turbulence that drives the observed supersonic non-thermal motions during the collapse, in particular in high-mass regions, and at which scales gravity becomes eventually dominant over the turbulence of the interstellar medium. This topic has been investigated by observing the dynamics of a carefully selected sample of 70 micron quiet clumps, chosen to cover a wide range of masses and surface densities, and compared with the dynamics of the parent filaments in which they are embedded. The dynamics at different scales and densities have been analyzed by combining observations of relatively low-density tracers (CO lines) at the filament scales, with high-density tracers (N2H+ (1-0) an HCO+ (1-0)) at the clump scales. We observe a continuous interplay between turbulence and gravity, where the former creates structures at all scales and the latter takes the lead when a critical value of the surface density is reached (namely, Σ ~ 0.1 g cm-2). In the densest filaments this transition can occur at the parsec, or even larger scales, leading to a global collapse of the whole region and most likely to the formation of the massive objects. This work will be further extended by looking at the dynamics in sub-parsec regions for a complete, muli-scale vision of the dynamics in star forming objects thanks to the ALMAGAL ALMA large program. | |
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| Caption: Velocity dispersion vs. radius relation obtained combining clumps and their parent filaments for ~25 objects, divided for different surface density (Σ) regimes of the identified clumps. Blue: clumps with Σ < 0.05 g cm-2; Green: clumps with 0.05 ≤ Σ ≤ 0.1 g cm-2; Red: clumps with Σ > 0.1 g cm-2. The plot shows an excess of velocity dispersion in the highest durface density clumps which is likely driven by the higher gravitational potential of these regions. | |
| Collaborators: G.A. Fuller, U Manchester, UK A. Duarte-Cabral, U Cardiff, UK D. Elia, IAPS-INAF, IT S. Molinari, IAPS-INAF, IT N. Peretto, U Cardiff, UK S. Schisano, IAPS-INAF, IT |
Key publication
Suggested Session: Turbulence & Cloud Dynamics |