Accretion and Diffusion Timescales in Sheets and Filaments

Abstract

A comparison of accretion and (turbulent) magnetic diffusion timescales for sheets and filaments demonstrates that dense star-forming clouds generally will -- under realistic conditions -- become supercritical due to mass accretion on timescales at least an order of magnitude shorter than ambipolar and/or turbulent diffusion timescales. Thus, ambipolar or turbulent diffusion -- while present -- is unlikely to control the formation of cores and stars.

12 pages, 6 figures, accepted by MNRAS

References in corpus (12)

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• Aspect Ratio Dependence of the Free-Fall Time for Non-Spherical Symmetries
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• On the gravitational content of molecular clouds and their cores
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Cited by in corpus (7)

• Radiation Magnetohydrodynamic Simulations of Protostellar Collapse: Non-Ideal Magnetohydrodynamic Effects and Early Formation of Circumstellar Disks
• Structure and Stability of Filamentary Clouds Supported by Lateral Magnetic Field
• The impact of magnetic fields on the chemical evolution of the supernova-driven ISM
• Stability of filaments in star-forming clouds and the formation of prestellar cores in them
• Structure, Dynamics and Deuterium Fractionation of Massive Pre-Stellar Cores
• Magnetic field measurement in TMC-1C using 22.3 GHz CCS Zeeman splitting
• Stellar feedback and triggered star formation in the prototypical bubble RCW 120