Reconnection current sheet structure in a turbulent medium

Autor(es)

Vishniac, E. T. ^[1] ; Pillsworth, S. ^[2] ; Eyink, G. ^[3] ; Kowal, G. ^[4] ; Lazarian, A. ^[5] ; Murray, S. ^[6]

Afiliação do(s) autor(es)

^[1] Univ Saskatchewan, Dept Phys & Engn Phys, Saskatoon, SK S7N 5E2 - Canada

^[2] McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1 - Canada

^[3] Johns Hopkins Univ, Dept Appl Math & Stat, Baltimore, MD 21218 - USA

^[4] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-05508090 Sao Paulo - Brazil

^[5] Univ Wisconsin, Dept Astron, Madison, WI 53706 - USA

^[6] McMaster Univ, Dept Mech Engn, Hamilton, ON L8S 4M7 - Canada

• Tipo de documento: Artigo Científico
• Fonte: Nonlinear Processes in Geophysics; v. 19, n. 6, p. 605-610, 2012.
• Citações Web of Science: 7

Resumo

In the presence of turbulence, magnetic field lines lose their dynamical identity and particles entrained on field lines diffuse through space at a rate determined by the amplitude of the turbulence. In previous work (Lazarian and Vishniac, 1999; Kowal et al., 2009; Eyink et al., 2011) we showed that this leads to reconnection speeds which are independent of resistivity. In particular, in Kowal et al. (2009) we showed that numerical simulations were consistent with the predictions of this model. Here we examine the structure of the current sheet in simulations of turbulent reconnection. Laminar flows consistent with the Sweet-Parker reconnection model produce very thin and well ordered currents sheets. On the other hand, the simulations of Kowal et al. (2009) show a strongly disordered state even for relatively low levels of turbulence. Comparing data cubes with and without reconnection, we find that large scale field reversals are the cumulative effect of many individual eddies, each of which has magnetic properties which are not very different from turbulent eddies in a homogeneous background. This implies that the properties of stationary and homogeneous MHD turbulence are a reasonable guide to understanding turbulence during large scale magnetic reconnection events. In addition, dissipation and high energy particle acceleration during reconnection events take place over a macroscopic volume, rather than being confined to a narrow zone whose properties depend on microscopic transport coefficients. (AU)

• Processo FAPESP: 09/50053-8 - Magnetic reconnection and particle acceleration in astrophysical sources and diffuse media
• Beneficiário: Grzegorz Kowal
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado