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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Magnetic flux transport by turbulent reconnection in astrophysical flows

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Autor(es):
de Gouveia Dal Pino, E. M. [1] ; Leao, M. R. M. [1] ; Santos-Lima, R. [1] ; Guerrero, G. [2] ; Kowal, G. [1] ; Lazarian, A. [3]
Número total de Autores: 6
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-05508090 Sao Paulo - Brazil
[2] Stanford Univ, Hansen Expt Phys Lab, Stanford, CA 94305 - USA
[3] Univ Wisconsin, Dept Astron, Madison, WI 53706 - USA
Número total de Afiliações: 3
Tipo de documento: Artigo Científico
Fonte: PHYSICA SCRIPTA; v. 86, n. 1 JUL 2012.
Citações Web of Science: 7
Resumo

The role of magnetohydrodynamics (MHD) turbulence in astrophysical environments is still highly debated. An important question that permeates this debate is the transport of magnetic flux. This is particularly important, for instance, in the context of star formation. When clouds collapse gravitationally to form stars, there must be some magnetic flux transport. Otherwise, the newborn stars would have magnetic fields several orders of magnitude larger than the observed ones. Also, the magnetic flux that is dragged in the late stages of the formation of a star can remove all the rotational support from the accretion disc that grows around the protostar. The efficiency of the mechanism that is often invoked to allow transport of magnetic fields at different stages of star formation, namely ambipolar diffusion, has recently been put in check. We discuss here an alternative mechanism for magnetic flux transport which is based on turbulent fast magnetic reconnection. We review recent results from three-dimensional MHD numerical simulations that indicate that this mechanism is very efficient in decoupling and transporting magnetic flux from the inner denser regions to the outskirts of collapsing clouds at different stages of star formation. We discuss this mechanism also in the context of dynamo processes and speculate that it can play a role both in solar dynamo and in accretion disc dynamo processes. (AU)

Processo FAPESP: 07/04551-0 - Turbulência no meio intergaláctico e a origem e evolução dos campos magnéticos cósmicos
Beneficiário:Reinaldo Santos de Lima
Linha de fomento: Bolsas no Brasil - Doutorado Direto
Processo FAPESP: 06/50654-3 - Investigação de fenômenos de altas energias e plasmas astrofísicos: teoria, observação e simulações numéricas
Beneficiário:Elisabete Maria de Gouveia Dal Pino
Linha de fomento: Auxílio à Pesquisa - Temático