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| EPoS Contribution |
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A Significant Role of Magnetic Field and Protostellar
Turbulence on the Formation and Evolution of Dense Cores
in Clustered vs. Distributed Star Formation
Fumitaka Nakamura National Astronomical Observatory of Japan, Japan | |
| We performed 3D MHD turbulent simulations of clustered and distributed star formation including protostellar outflow feedback, and extensively investigated the physical properties of the dense cores identified from the 3D density data cubes obtained from the simulation. We found that turbulent pressures generated by protostelar outflows greatly affect the dynamics of the cores in clustered star formation. Our simulations also indicate that the physical properties of the cores depend significantly on the magnetic field strength. In the presence of moderately strong magnetic field, the internal motions of the cores tend to be reduced and thus the cores tend not to be far from the virial equilibria when the density contrast between the core center and the envelope becomes large. The virial ratios (alpha) reasonably follow the relation of alpha = M^{-2/3}. In contrast, in the presence of weak magnetic field or no magnetic field, the cores tend to be far from virial equilibrium and the virial ratio-mass relation has a large dispersion. Such a feature is apparently inconsistent with observations, suggesting that at least moderately strong magnetic field is needed to reproduce the obsevational properties of dense cores even in cluster formation environments. The 3D magnetic field structures of the cores are often highly distorted by ambient turbulent field generated by protostellar outflows and does not show well-ordered (hour-glass) shape. In other words, the magnetic field structures of the cores are different from those of the distributed star formation environments, for which the strong magnetic field associated with the cores tend to be spatially well ordered. If time permits, we would like to present the observational results of nearby cluster forming clumps such as rho Oph for dense cores and for protostellar outflows and compare them with the numerical simulations. | |
| Collaborators: Z.-Y. Li, University of Virginia, USA R. Kawabe et al., Nobeyama Radio Observatory, Japan Y. Kitamura, JAXA/ISAS, Japan |
Key publication |