English
Related papers

Related papers: Alfven Wave Mode Conversion in Neutron Star Magnet…

200 papers

Alfv\'en waves may be generated via mode conversion from fast magneto-acoustic waves near their reflection level in the solar atmosphere, with implications both for coronal oscillations and for active region helio-seismology. In active…

Solar and Stellar Astrophysics · Physics 2015-05-28 Paul S. Cally , Shelley C. Hansen

We study the conversion of fast magneto-acoustic waves to Alfven waves by means of 2.5D numerical simulations in a sunspot-like magnetic configuration. A fast, essentially acoustic, wave of a given frequency and wave number is generated…

Solar and Stellar Astrophysics · Physics 2015-06-03 Elena Khomenko , Paul Cally

In this paper, results of 2.5-dimensional magnetohydrodynamical simulations are reported for the magnetic reconnection of non-perfectly antiparallel magnetic fields. The magnetic field has a component perpendicular to the computational…

Solar and Stellar Astrophysics · Physics 2015-05-18 Hiromitsu Kigure , Kunio Takahashi , Kazunari Shibata , Takaaki Yokoyama , Satoshi Nozawa

We study the coupling of magneto-acoustic waves to Alven waves using 2.5D numerical simulations. In our experiment, a fast magnetoacoustic wave of a given frequency and wavenumber is generated below the surface. The magnetic field in the…

Solar and Stellar Astrophysics · Physics 2015-05-20 Elena Khomenko , Paul Cally

We present an one-dimensional numerical study of Alfven waves propagating along a radial magnetic field. Neglecting losses, any spherical Alfven wave, no matter how small its initial amplitude is, becomes nonlinear at sufficiently large…

Astrophysics · Physics 2009-10-30 Ulf Torkelsson , G. Christopher Boynton

The interaction of a weakly nonlinear Alfv\'enic pulse with an Alfv\'en speed inhomogeneity in the direction perpendicular to the magnetic field is investigated. Identically to the phase mixing experienced by a harmonic Alfv\'en wave, sharp…

Astrophysics · Physics 2009-11-07 D. Tsiklauri , T. D. Arber , V. M. Nakariakov

Context: MHD waves and magnetic null points are both prevalent in many astrophysical plasmas, including the solar atmosphere. Interaction between waves and null points has been implicated as a possible mechanism for localised heating…

Solar and Stellar Astrophysics · Physics 2015-06-16 J. O. Thurgood , J. A. McLaughlin

The conversion of fast waves to the Alfven mode in a realistic sunspot atmosphere is studied through three-dimensional numerical simulations. An upward propagating fast acoustic wave is excited in the high-beta region of the model. The new…

Solar and Stellar Astrophysics · Physics 2015-06-11 T. Felipe

Recently it was found that helical magnetized flows efficiently amplify Alfv\'en waves (Rogava et al. 2003, A&A, v.399, p.421). This robust and manifold nonmodal effect was found to involve regimes of transient algebraic growth (for purely…

Astrophysics · Physics 2009-11-07 Andria Rogava , Gianluigi Bodo , Silvano Massalgia , Zaza Osmanov

Using the energy variational method of magneto-solid-mechanical theory of a perfectly conducting elastic medium threaded by magnetic field, the frequency spectrum of Lorentz-force-driven global torsional nodeless vibrations of a neutron…

Solar and Stellar Astrophysics · Physics 2015-05-13 S. I. Bastrukov , H. -K. Chang , I. V. Molodtsova , E. H. Wu , G. -T. Chen , S. -H. Lan

Highly dynamic magnetospheric perturbations in neutron star environments can naturally account for the features observed in Gamma-ray Burst spectra. The source distribution, however, appears to be extragalactic. Although noncatastrophic…

Astrophysics · Physics 2009-10-22 M. Fatuzzo , F. Melia

We study the propagation and transmission of Alfven waves in the context of cylindrical geometry. This approximates the polar cap region of aligned pulsar with strong magnetic fields. Non-propagating region appears in the presence of…

Astrophysics · Physics 2009-11-10 Yasufumi Kojima , Taishi Okita

This paper is devoted to the study of the gravitational instability of a medium permeated by a uniform magnetic field along which a circularly polarized Alfven wave propagates. We concentrate on the case of perturbations purely transverse…

Astrophysics · Physics 2009-11-07 Adriana Gazol , Thierry Passot

This paper explores small-scale departures from force-free electrodynamics around a rotating neutron star, extending our treatment of resistive instability in a quantizing magnetic field. A secondary, Cerenkov instability is identified:…

High Energy Astrophysical Phenomena · Physics 2022-09-28 Christopher Thompson

Rockets and satellites have previously observed small-scale Alfv\'en waves inside large-scale downward field-aligned currents and numerical simulations have associated their formation with self-consistent magnetosphere-ionosphere coupling.…

Space Physics · Physics 2013-04-05 Alexander J. B. Russell , Andrew N. Wright

Using advanced numerical magneto-hydrodynamic simulations of the magnetised solar photosphere, including non-grey radiative transport and a non-ideal equation of state, we analyse plasma motions in photospheric magnetic vortices. We…

Solar and Stellar Astrophysics · Physics 2015-06-17 S. Shelyag , P. S. Cally , A. Reid , M. Mathioudakis

Large-amplitude Alfv\'en waves are ubiquitous in space plasmas and a main component of magnetohydrodynamic (MHD) turbulence in the heliosphere. As pump waves they are prone to parametric instability by which they can generate cyclotron and…

Plasma Physics · Physics 2012-01-16 Eckart Marsch , Daniel Verscharen

Magnetars exhibit a variety of transient high-energy phenomena in the form of bursts, outbursts, and giant flares. It is a common belief that these events originate in the sudden release of magnetic energy due to the rearrangement of a…

High Energy Astrophysical Phenomena · Physics 2023-03-22 Petros Stefanou , Jose A. Pons , Pablo Cerdá-Durán

Numerical simulations of force-free, degenerate (ffde)pulsar and black hole magnetospheres are often based on 1-D characteristics. In particular, the plasma wave polarizations that can be propagated along the 1-D characteristics determine…

Astrophysics · Physics 2009-11-10 Brian Punsly

Aims: Propagation and energy transfer of torsional Alfv\'en waves in solar magnetic flux tubes of axial symmetry is studied. Methods: An analytical model of a solar magnetic flux tube of axial symmetry is developed by specifying a magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-20 K. Murawski , A. Solov'ev , Z. E. Musielak , A. K. Srivastava , J. Kraskiewicz