We demonstrate the feasibility of using a nonconforming nite element method on an unstructured grid in solving a magnetospheric physics problem. We use this approach to construct a global discrete model of the magnetic eld of the magnetosphere that includes the eeects of shielding currents at the outer boundary (the magnetopause). As in the approach of 17] the internal magnetospheric eld model ...

The kinematic induction equation of MHD is solved numerically in the case of the normal \111" ABC ow using a general staggered mesh method. Careful 3-D visualizations of the topology of the magnetic eld reveal that previous conclusions about the modes of operation of this type of kinematic dynamo must be revised. The two known windows of dynamo action at low and high magnetic Reynolds number , ...

We explore the importance of magnetic-field-oriented thermal conduction in the interaction of supernova remnant (SNR) shocks with radiative gas clouds and in determining the mass and energy exchange between the clouds and the hot surrounding medium. We perform 2.5D MHD simulations of a shock impacting on an isolated gas cloud, including anisotropic thermal conduction and radiative cooling; we c...

We consider the classic MHD turbulent dynamo operating in a thin, Keplerian accretion disk powered by turbulent viscous stress. The character of the turbulence is encapsulated into two constant parameters: the Shakura-Sunyaev dimensionless viscosity, SS , and the Coriolis number, = 2 corr. The dependence of the total electromotive force on SS and is derived and the dynamo-generated magnetic eld...

The generation of magnetic elds by a battery, operating in an ion-electron plasma around a Kerr black hole, is studied in the 3+1 split of the Kerr metric. It is found that the gravitomagnetic contributions to the electron partial pressure are able to drive currents. The strength of the equilibrium magnetic eld should be higher than for the classical Biermann battery, which is found to operate ...

We reanalyze the e ect of magnetic elds in BBN, incorporating several features which were omitted in previous analyses. We nd that the e ects of coherent magnetic elds on the weak interaction rates and the electron thermodynamic functions ( e, Pe, and d e=dT ) are unimportant in comparison to the contribution of the magnetic eld energy density in BBN. In consequence the e ect of including magne...

If the current sheet between adjacent twisted magnetic °ux tubes is suf̄ciently thin, the electron °ow velocity becomes comparable to the Alfv¶en velocity and can destabilize collisionless Alfv¶en waves. The threshold for instability in force-free plasmas is calculated for both inertial and kinetic Alfv¶en wave regimes. When there is strong magnetic shear, unstable kinetic Alfv¶en waves can reso...

Previous work on the emission from isolated old neutron stars (IONSs) accreting from the interstellar medium (ISM) has focused on gravitational captureÈi.e., Bondi accretion. We propose a new class of sources that accrete via magnetic interaction with the ISM. While for the Bondi mechanism the accretion rate decreases with increasing neutron star velocity, in magnetic accretors (MAGACs) M0 Bond...

We consider an ion whose motion is con®ned to a plane perpendicular to a constant magnetic ®eld. A harmonic trapping ®eld is applied within the plane of the ion’s motion, together with some unspeci®ed irradiating probe beam. By determining the dynamics of the ion we show that the particle theory is formally equivalent to that of a coupled massive ...1‡ 2†-dimensional vector Boson ®eld. The ®eld...

Single crystal Y3Fe5O12 (YIG) lm was grown onto (111) oriented gadolinium gallium garnet (GGG) substrate by the liquid phase epitaxy (PLD) technique. The X-ray di raction measurements showed that epitaxial growth of the lm along its (111) axis. The surface characteristic was investigated by atomic force microscopy (AFM) measurement. The magnetic eld sensor consisted of a rectangular shape with ...