Elisabete M. de Gouveia Dal Pino, Márcia R. M. Leão, Reinaldo Santos-Lima, Gustavo Guerrero, Grzegorz Kowal, Alex Lazarian
The role of 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 new born 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 disk that grows
around the protostar. The efficiency of the mechanism which is often invoked to
allow the transport of magnetic fields in the different stages of star
formation, namely, the ambipolar diffusion, has been lately put in check. We
here discuss an alternative mechanism for magnetic flux transport which is
based on turbulent fast magnetic reconnection. We review recent results
obtained from 3D MHD numerical simulations that indicate that this mechanism is
very efficient for decoupling and transport magnetic flux from the inner denser
regions to the outskirts of collapsing clouds in the different stages of star
formation. We also discuss this mechanism in the context of dynamo processes
and speculate that it can play a role both in the solar dynamo and in accretion
disk dynamo processes.
View original:
http://arxiv.org/abs/1112.4871
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