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| EPoS Contribution |
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The Core Mass Function in Molecular Clouds and Comparison with Observations
Telemachos Ch. Mouschovias University of Illinois at Urbana-Champaign, Urbana, IL, USA | |
| Since Salpeter obtained his well known result on the stellar Initial Mass Function (IMF), many mechanisms have been proposed that are capable of explaining at least the high-end slope of the IMF. More recently, observations of molecular clouds (MCs) have revealed an ("initial") Core Mass Function (CMF) very similar to the stellar IMF, implying that the fragmentation mechanism of MCs may also be responsible for determining the stellar IMF. Several mechanisms have also been proposed for explaining the CMF with varying degrees of success. We have revisited the problem analytically from first principles and considered the effects of gravity, magnetic support, ambipolar diffusion and, currently, rotation and magnetic braking. The results/predictions are in excellent quantitative agreement with existing observations of the CMF (e.g., in Orion) and can further be tested by upcoming Herschel observations. They are also robust in that they are not sensitive to the (very few) input free parameters of the problem, provided that these parameters remain within their observationally allowed range of values. Our results are dinstict from other predictions, e.g., based on supersonic/superAlfvenic turbulence, thereby allowing discriminative observational tests. In parallel to the analytical calculations, we have also obtained results using three-dimensional numerical simulations. Surprising predictions are made, not obtainable by analytical means, but also testable by existing and upcoming observations. | |
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| Caption: Predicted CMF (normalized to the initial thermal critical mass m_T,0 ) for P_ext=0.1 and tau_ni,0=0.162 (dashed line), 0.230 (solid line) and 0.325 (dotted line). The corresponding power-law exponents alpha are also shown. The data are from Nutter & Ward-Thompson (2007) and refer to starless cores in Orion, see also key reference. | |
| Collaborators: D. Christie, UIUC, USA M. Kunz, Oxford, UK |
Key publication
Suggested Session: Cores and Collapse, Herschel, Magnetic Fields |