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Dynamo in the Intra-Cluster Medium: Simulation of CGL-MHD Turbulent Dynamo

Published online by Cambridge University Press:  08 June 2011

R. Santos-Lima
Affiliation:
IAG, Universidade de São Paulo, Rua do Matão 1226, São Paulo 05508-090, Brazil email: [email protected]
E. M. de Gouveia Dal Pino
Affiliation:
IAG, Universidade de São Paulo, Rua do Matão 1226, São Paulo 05508-090, Brazil email: [email protected]
A. Lazarian
Affiliation:
Astronomy Department, University of Wisconsin, Madison, WI, USA
G. Kowal
Affiliation:
IAG, Universidade de São Paulo, Rua do Matão 1226, São Paulo 05508-090, Brazil email: [email protected]
D. Falceta-Gonçalves
Affiliation:
NAC, Universidade Cruzeiro do Sul, Rua Galvão Bueno 868, São Paulo 01506-000, Brazil
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Abstract

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The standard magnetohydrodynamic (MHD) description of the plasma in the hot, magnetized gas of the intra-cluster (ICM) medium is not adequate because it is weakly collisional. In such collisionless magnetized gas, the microscopic velocity distribution of the particles is not isotropic, giving rise to kinetic effects on the dynamical scales. These kinetic effects could be important in understanding the turbulence as well as the amplification and maintenance of the magnetic fields in the ICM. It is possible to formulate fluid models for collisonless or weakly collisional gas by introducing modifications in the MHD equations. These models are often referred as kinetic MHD (KMHD). Using a KMHD model based on the CGL-closure, which allows the adiabatic evolution of the two components of the pressure tensor (the parallel and perpendicular components with respect to the local magnetic field), we performed 3D numerical simulations of forced turbulence in order to study the amplification of an initially weak seed magnetic field. We found that the growth rate of the magnetic energy is comparable to that of the ordinary MHD turbulent dynamo, but the magnetic energy saturates in a level smaller than that of the MHD case. We also found that a necessary condition for the dynamo to operate is to impose constraints on the anisotropy of the pressure.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2011

References

Chew, G. F., Goldberger, M. L., & Low, F. E. 1956, Royal Society of London Proceedings Series A, 236, 112Google Scholar
Enßlin, T. A. & Vogt, C. 2006, A&A, 453, 447Google Scholar
Kowal, G., Falceta-Goncalves, D. A., & Lazarian, A. 2010, arXiv:1012.5125Google Scholar
Kulsrud, R. M. 1983, Basic Plasma Physics: Selected Chapters, Handbook of Plasma Physics, Volume 1, 1Google Scholar
Sharma, P., Hammett, G. W., Quataert, E., & Stone, J. M. 2006, ApJ, 637, 952CrossRefGoogle Scholar