Magnetic energy release near accreting black holes

1994 ◽  
Vol 68 (1-4) ◽  
pp. 309-320 ◽  
Author(s):  
Roeland F. Van Oss
Keyword(s):  
Black Holes ◽  
Energy Release ◽  
Magnetic Energy ◽  
Magnetic Energy Release

Magnetic Energy Release and Transients in the Solar Flare of 2000 July 14

2001 ◽  
Vol 550 (1) ◽  
pp. L105-L108 ◽  
Author(s):  
A. G. Kosovichev ◽  
V. V. Zharkova
Keyword(s):  
Solar Flare ◽  
Energy Release ◽  
Magnetic Energy ◽  
Magnetic Energy Release

scholarly journals Magnetic Energy Release in Dynamic Fan Reconnection Models

1999 ◽  
Vol 510 (2) ◽  
pp. 1045-1052 ◽  
Author(s):  
I. J. D. Craig ◽  
A. N. McClymont
Keyword(s):  
Energy Release ◽  
Magnetic Energy ◽  
Magnetic Energy Release

scholarly journals Large polar caps for twisted magnetosphere of magnetars

2019 ◽  
Author(s):  
H Tong
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Energy Release ◽  
Open Field ◽  
Magnetic Energy ◽  
Hot Spot ◽  
Open Field Line ◽  
Field Lines ◽  
The Magnetic Field ◽  
Magnetic Energy Release

Abstract The magnetic field of magnetars may be twisted compared with that of normal pulsars. Previous works mainly discussed magnetic energy release in the closed field line regions of magnetars. For a twisted magnetic field, the field lines will inflate in the radial direction. Similar to normal pulsars, the idea of light cylinder radius is introduced. More field lines will cross the light cylinder and become open for a twisted magnetic field. Therefore, magnetars may have a large polar cap, which may correspond to the hot spot during outburst. Particle flow in the open field line regions will result in the untwisting of the magnetic field. Magnetic energy release in the open field line regions can be calculated. The model calculations can catch the general trend of magnetar outburst: decreasing X-ray luminosity, shrinking hot spot etc. For magnetic energy release in the open field line regions, the geometry will be the same for different outburst in one magnetar.

Turbulent impulsive magnetic energy release from electron scale reconnection

2007 ◽  
Vol 14 (1) ◽  
pp. 012902 ◽  
Author(s):  
W. Horton ◽  
J.-H. Kim ◽  
F. Militello ◽  
M. Ottaviani
Keyword(s):  
Energy Release ◽  
Magnetic Energy ◽  
Magnetic Energy Release

Fast Magnetic Reconnection by Turbulence with High Landquist Number

2020 ◽  
Author(s):  
Liping Yang ◽  
Hui Li ◽  
Fan Guo ◽  
Xiancan Li ◽  
Shengtai Li ◽  
...  
Keyword(s):  
Magnetic Reconnection ◽  
Energy Release ◽  
Magnetic Energy ◽  
Three Dimensional ◽  
Turbulent Plasma ◽  
Turbulence Level ◽  
Reconnection Rate ◽  
Numerical Studies ◽  
Large Opening ◽  
Magnetic Energy Release

<p>We report detailed numerical studies of magnetic reconnection in high-Lundquist-number, turbulent plasma by means of a three-dimensional (3D) resistive magnetohydrodynamics model. It is found that although turbulence is pre-existing, magnetic fields still restructure themselves to shape many X-points with evident mean inflow/outflow as well as the hierarchically generated magnetic flux ropes (plasmoids in 2D) with twist field lines. Moreover, the turbulence facilitates magnetic reconnections, and makes the normalized global reconnection rate reach ∼ 0.02 − 0.1, corresponding to turbulence level from very low to high and magnetic energy release from feeble to violent. The rate is nearly independent on the Lundquist number, and thus the fast turbulent reconnection occurs. A stochastic separation of the reconnected magnetic field lines with large opening angles follows a super-diffusion, indicating the broadening of outflow regions owing to the turbulence. These findings manifest that with the high Lundquist numbers (S ≥ 10^4), the 3D reconnection is turbulent and fast.</p>

scholarly journals Magnetic energy release: flares and coronal mass ejections

2009 ◽  
Vol 5 (S264) ◽  
pp. 257-266 ◽  
Author(s):  
Cristina H. Mandrini
Keyword(s):  
Magnetic Field ◽  
Energy Release ◽  
Coronal Mass Ejections ◽  
Magnetic Energy ◽  
Radiative Energy ◽  
Electromagnetic Spectrum ◽  
Combined Analysis ◽  
Magnetic Field Topology ◽  
The Magnetic Field ◽  
Magnetic Energy Release

AbstractFree energy stored in the magnetic field is the source that powers solar and stellar activity at all temporal and spatial scales. The energy released during transient atmospheric events is contained in current-carrying magnetic fields that have emerged twisted and may be further stressed via motions in the lower atmospheric layers (i.e. loop-footpoint motions). Magnetic reconnection is thought to be the mechanism through which the stored magnetic energy is transformed into kinetic energy of accelerated particles and mass flows, and radiative energy along the whole electromagnetic spectrum. This mechanism works efficiently at scale lengths much below the spatial resolution of even the highest resolution solar instruments; however, it may imply a large-scale restructuring of the magnetic field inferred indirectly from the combined analysis of observations and models of the magnetic field topology. The aftermath of magnetic energy release includes events ranging from nanoflares, which are below our detection limit, to powerful flares, which may be accompanied by the ejection of large amounts of plasma and magnetic field (so called coronal mass ejections, CMEs), depending on the amount of total available free magnetic energy, the magnetic flux density distribution, the magnetic field configuration, etc. We describe key observational signatures of flares and CMEs on the Sun, their magnetic field topology, and discuss how the combined analysis of solar and interplanetary observations can be used to constrain the flare/CME ejection mechanism.

scholarly journals Dynamical Magnetic Energy Release of Current Loops in the Corona: Effects of Toroidal Forces

1989 ◽  
Vol 104 (2) ◽  
pp. 293-296
Author(s):  
James Chen
Keyword(s):  
Energy Dissipation ◽  
Simple Model ◽  
Range Of Motion ◽  
Energy Release ◽  
Magnetic Energy ◽  
Current Loop ◽  
Magnetic Current ◽  
Wide Range ◽  
A Current ◽  
Magnetic Energy Release

AbstractWe discuss a mechanism whereby a current loop embedded in plasmas such as the solar and stellar coronae can dissipate magnetic energy without resistive effects or reconnection. This mechanism arises from the motion of magnetic/current structures driven by “toroidal forces”. Using a simple model loop, we show that it can exhibit a wide range of motion with correspondingly wide range of magnetic energy dissipation rates. For example, a loop with ~20G can attain expansion velocities of ~1200km s–1 under solar coronal conditions, dissipating ~1032erg in a few tens of minutes.

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