English
Related papers

Related papers: Triggering magnetar outbursts in 3D force-free sim…

200 papers

The X-ray spectra observed in the persistent emission of magnetars are evidence for the existence of a magnetosphere. The high-energy part of the spectra is explained by resonant cyclotron upscattering of soft thermal photons in a twisted…

High Energy Astrophysical Phenomena · Physics 2011-09-28 Daniele Viganò , Jose A. Pons , Juan A. Miralles

The sharp magnetic discontinuities which naturally appear in solar magnetic flux tubes driven by turbulent photospheric motions are associated with intense currents. \citet{Par83} proposed that these currents can become unstable to a…

Astrophysics · Physics 2009-11-10 Kaspar Arzner , Loukas Vlahos

Magnetohydrodynamic (MHD) instabilities can play an important role in the structure and dynamics of the pulsar magnetosphere. We consider the instabilitycaused by differential rotation that is suggested by many theoretical models. Stability…

High Energy Astrophysical Phenomena · Physics 2015-06-04 V. Urpin

We perform force-free simulations for a neutron star orbiting a black hole, aiming at clarifying the main magnetosphere properties of such binaries towards their innermost stable circular orbits. Several configurations are explored, varying…

High Energy Astrophysical Phenomena · Physics 2021-09-08 Federico Carrasco , Masaru Shibata , Oscar Reula

We perform direct numerical simulations of the equations of magnetohydrodynamics with external random forcing and in the presence of gravity. The domain is divided into two parts: a lower layer where the forcing is helical and an upper…

Solar and Stellar Astrophysics · Physics 2014-10-20 Dhrubaditya Mitra , A. Brandenburg , N. Kleeorin , I. Rogachevskii

X-ray observations of many clusters of galaxies reveal the presence of edges in surface brightness and temperature, known as "cold fronts". In relaxed clusters with cool cores, these edges have been interpreted as evidence for the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 J. A. ZuHone , M. Markevitch , D. Lee

Magnetic field strengths inferred for relativistic outflows including gamma-ray bursts (GRB) and active galactic nuclei (AGN) are larger than naively expected by orders of magnitude. We present three-dimensional relativistic…

Astrophysics · Physics 2009-11-13 Weiqun Zhang , Andrew MacFadyen , Peng Wang

Flaring release of magnetic energy in solar corona is only possible if the magnetic field deviates from a potential one. We show that the linear MHD modes excited on top of the non-potential magnetic field possess a nonzero kinetic…

Solar and Stellar Astrophysics · Physics 2015-06-12 Gregory D. Fleishman , Igor N. Toptygin

We have performed a three-dimensional magnetohydrodynamic simulation to study the emergence of a twisted magnetic flux tube from -20,000 km of the solar convection zone to the corona through the photosphere and the chromosphere. The middle…

Solar and Stellar Astrophysics · Physics 2015-06-03 S. Toriumi , T. Yokoyama

We present results of three-dimensional (3D), radiation-magnetohydrodynamics (MHD) simulations of core-collapse supernovae in full general relativity (GR) with spectral neutrino transport. In order to study the effects of progenitor's…

High Energy Astrophysical Phenomena · Physics 2020-06-24 Takami Kuroda , Almudena Arcones , Tomoya Takiwaki , Kei Kotake

Solar flares occur due to the sudden release of energy stored in active-region magnetic fields. To date, the pre-cursors to flaring are still not fully understood, although there is evidence that flaring is related to changes in the…

Solar and Stellar Astrophysics · Physics 2012-02-01 Sophie A. Murray , D. Shaun Bloomfield , Peter T. Gallagher

Using a rotating flat layer heated from below as an example, we consider effects which lead to stabilizing an exponentially growing magnetic field in magnetostrophic convection in transition from the kinematic dynamo to the full non-linear…

Fluid Dynamics · Physics 2015-05-18 P. Hejda , M. Reshetnyak

Solar energetic events are caused by the release of magnetic energy accumulated in the solar atmosphere. To understand their initiating physical mechanisms, the dynamics of the coronal magnetic fields must be studied. Unfortunately, the…

Solar and Stellar Astrophysics · Physics 2024-08-14 Yeongmin Kang , Takafumi Kaneko , K. D. Leka , Kanya Kusano

Direct detection of spontaneous spin fluctuations, or "magnetization noise", is emerging as a powerful means of revealing and studying magnetic excitations in both natural and artificial frustrated magnets. Depending on the lattice and…

Mesoscale and Nanoscale Physics · Physics 2023-11-15 M. Goryca , X. Zhang , J. Ramberger , J. D. Watts , C. Nisoli , C. Leighton , P. Schiffer , S. A. Crooker

Twisted magnetic fields are frequently seen to emerge above the visible surface of the Sun. This emergence is usually associated with the rise of buoyant magnetic flux structures. Here we ask how magnetic fields from a turbulent large-scale…

Solar and Stellar Astrophysics · Physics 2010-11-22 J. Warnecke , A. Brandenburg

The diffusion of astrophysical magnetic fields in conducting fluids in the presence of turbulence depends on whether magnetic fields can change their topology via reconnection in highly conducting media. Recent progress in understanding…

Astrophysics of Galaxies · Physics 2012-12-17 R. Santos-Lima , A. Lazarian , E. M. de Gouveia Dal Pino , J. Cho

Crustquake events may be connected with both rapid spin-up `glitches' within the regular slowdown of neutron stars, and high-energy magnetar flares. We argue that magnetic field decay builds up stresses in a neutron star's crust, as the…

High Energy Astrophysical Phenomena · Physics 2015-06-23 S. K. Lander , N. Andersson , D. Antonopoulou , A. L. Watts

Abstract: Assuming that the numerical diffusivity triggered by violations of the force-free electrodynamics constraints is a proxy for the physical resistivity, we examine its impact on the overall dynamics of force-free aligned pulsar…

High Energy Astrophysical Phenomena · Physics 2021-10-13 J. F. Mahlmann , M. A. Aloy

Axisymmetric magnetohydrodynamic (MHD) simulations have been applied to investigate the interrelation of a central stellar magnetosphere and stellar wind with a surrounding magnetized disk outflow and how the overall formation of a large…

Astrophysics · Physics 2011-02-11 Christian Fendt

Magnetic helicity fluxes in turbulently driven alpha^2 dynamos are studied to demonstrate their ability to alleviate catastrophic quenching. A one-dimensional mean-field formalism is used to achieve magnetic Reynolds numbers of the order of…

Solar and Stellar Astrophysics · Physics 2012-07-17 Simon Candelaresi , Axel Brandenburg
‹ Prev 1 3 4 5 6 7 10 Next ›