Thursday, March 12, 2009 - 4:15pm
Alexander Lazarian (University of Wisconsin):
"Magnetic reconnection of weakly stochastic magnetic fields"
Abstract. I shall present a reconnection model for weakly stochastic magnetic field proposed in Lazarian & Vishniac (1999) and new 3D MHD simulations that support this model. The reconnection speed measured does not depend neither on Ohmic or anomalous resistivity, but only on the power input and injection scale of the turbulence. (Note that the turbulence is always driven weakly - with sub-Alfvenic velocities - and no small-scale reversals, that are appealed to in the ill-founded idea of turbulent diffusivity, are present.) I shall compare the theoretical and experimental scalings of the reconnection speed on the parameters of turbulence and the guide field. I shall discuss the implications of our model of reconnection for MHD simulations of interstellar medium, as well as the acceleration of cosmic rays, star formation and solar flares.