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Magnetic helicity fluxes and their effect on stellar dynamos

Published online by Cambridge University Press:  05 July 2012

Simon Candelaresi
Affiliation:
NORDITA, AlbaNova University Center, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden; and Department of Astronomy, Stockholm University, SE-10691 Stockholm, Sweden
Axel Brandenburg
Affiliation:
NORDITA, AlbaNova University Center, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden; and Department of Astronomy, Stockholm University, SE-10691 Stockholm, Sweden
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Abstract

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Magnetic helicity fluxes in turbulently driven α2 dynamos are studied to demonstrate their ability to alleviate catastrophic quenching. A one-dimensional mean-field formalism is used to achieve magnetic Reynolds numbers of the order of 105. We study both diffusive magnetic helicity fluxes through the mid-plane as well as those resulting from the recently proposed alternate dynamic quenching formalism. By adding shear we make a parameter scan for the critical values of the shear and forcing parameters for which dynamo action occurs. For this αΩ dynamo we find that the preferred mode is antisymmetric about the mid-plane. This is also verified in 3-D direct numerical simulations.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2012

References

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