Protostars and Planets VI, Heidelberg, July 15-20, 2013
Rapid Growth of ISM Magnetic Fields via a Fast Turbulent Dynamo
Tricco, Terrence (Monash University)
Price, Daniel (Monash University)
Federrath, Christoph (Monash University)
We have performed Smoothed Particle Magnetohydrodynamics simulations of the fast dynamo amplification of magnetic fields from isothermal, driven Mach 10 turbulence. Such turbulence is found in molecular clouds, and it would be expected that any initially small seed magnetic field would be exponentially increased through the conversion of turbulent energy. Our simulations begin with magnetic energy that is 10 orders of magnitude smaller than the kinetic energy which exponentially increases until reaching equipartition. The growth rate is dependent upon the Prandtl number, the ratio of viscous to resistive dissipation, with our simulations producing higher growth rates with increasing resolution and lower numerical dissipation. Molecular clouds should have even higher Prandtl numbers and saturate even faster. We have also developed a new switch to reduce numerical dissipation from artificial resistivity which yields increased magnetic field growth rates. Our results are compared with results from grid based methods, finding agreement on the rate of magnetic field growth.
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