scholarly journals Pulsar Electrodynamics — Pulsars and Puzzlers —

1996 ◽  
Vol 160 ◽  
pp. 409-416
Author(s):  
Shinpei Shibata
Keyword(s):  
Magnetic Field ◽  
Pair Creation ◽  
Gap Model ◽  
Pulsar Magnetosphere ◽  
Wind Model ◽  
Gedanken Experiment ◽  
Basic Understanding ◽  
Free Parameters ◽  
Pulsar Wind ◽  
Field Lines

AbstractA gedanken experiment presented here provides basic understanding of how the pulsar magnetosphere operates. We discuss current issues about the electric-field acceleration along magnetic field lines and subsequent pair creation, and also about the pulsar wind problem. It is stressed that any local model, such as the inner gap model, the outer gap model and the pulsar wind model, must have free parameters to link it to other part of the magnetosphere.

scholarly journals Electron Outflow in Axisymmetric Pulsar Magnetospheres

1985 ◽  
Vol 38 (5) ◽  
pp. 749 ◽  
Author(s):  
RR Burman
Keyword(s):  
Magnetic Field ◽  
Pulsar Magnetosphere ◽  
Poloidal Magnetic Field ◽  
Light Cylinder ◽  
Field Lines ◽  
Limiting Surface

Mestel et al. (1985) have recently introduced an axisymmetric pulsar magnetosphere model in which electrons leave the star with speeds that are non-negligible, but not highly relativistic, and flow with moderate acceleration, and with poloidal motion that is closely tied to the poloidal magnetic field lines, before reaching a limiting surface, near which rapid acceleration occurs. This paper presents an analysis of flows which either encounter the limiting surface beyond the light cylinder or do not meet it at all.

scholarly journals Distorted Dipole Magnetic Fields

1996 ◽  
Vol 160 ◽  
pp. 433-434
Author(s):  
Ron Burman
Keyword(s):  
Magnetic Field ◽  
Numerical Technique ◽  
Dipole Approximation ◽  
Pulsar Magnetosphere ◽  
Poloidal Magnetic Field ◽  
Numerical Work ◽  
Plasma Drift ◽  
Field Lines ◽  
Limiting Surface ◽  
The Magnetic Field

Mestel et al. (1985; MRΩ2) introduced an axisymmetric pulsar magnetosphere model in which electrons leave the star with non-negligible speeds and flow with moderate acceleration, and with poloidal motion that is closely tied to poloidal magnetic field lines, before reachingSL, a limiting surface near which rapid acceleration occurs. As well as these Class I flows, there exist Class II flows which do not encounter a region of rapid acceleration (Burman 1984, 1985b). The formalism introduced by MRΩ2to describe the moderately accelerated flows can be interpreted in terms of a plasma drift across the magnetic field, following injection along it (Burman 1985a).The MRΩ2formalism fully incorporates the toroidal magnetic field generated by the poloidal flow. The general formalism leaves the poloidal magnetic field unspecified, but, in the detailed development of MRΩ2, and in my papers, that field was taken to be the dipolar field of the star.Numerical work by Fitzpatrick & Mestel (1988a,b) suggested that the dipole approximation is inadequate. They developed a numerical technique for incorporating the modification to the poloidal magnetic field that is generated by the toroidal motions throughout the magnetosphere. They based their treatment on the hypothesis that those motions are such as to cancel the dipole field of the star, leaving a sextupole poloidal magnetic field at large distances.

Electron Outflow in Pulsar Magnetospheres

1984 ◽  
Vol 5 (4) ◽  
pp. 467-469 ◽  
Author(s):  
R. R. Burman
Keyword(s):  
Magnetic Field ◽  
Pulsar Magnetosphere ◽  
Field Lines ◽  
Limiting Surface

Mestel, Wang and Westfold (1984; ‘MWW’) have recently introduced a pulsar magnetosphere model in which electrons leave the star with non-negligible, but not highly-relativistic, speeds, and flow with moderate acceleration along magnetic field lines before reaching a limiting surface, near which rapid acceleration occurs. Such moderately accelerated flows are analysed here. A second class of flows, which do not encounter a region of rapid acceleration, is found.

scholarly journals Electron Outflow in Axisymmetric Pulsar Magnetospheres. II

1987 ◽  
Vol 40 (5) ◽  
pp. 687
Author(s):  
RR Burman
Keyword(s):  
Magnetic Field ◽  
Axial Magnetic Field ◽  
Lorentz Factor ◽  
Surface Flow ◽  
Stellar Surface ◽  
Extended Version ◽  
Pulsar Magnetosphere ◽  
Poloidal Magnetic Field ◽  
Field Lines ◽  
Limiting Surface

Tn the axisymmetric pulsar magnetosphere model of Mestel et al. (1985), electrons, following injection with non-negligible speeds from the stellar surface, flow with moderate acceleration, and with poloidal motion that is closely tied to poloidal magnetic field lines, before reaching a limiting surface, near which rapid acceleration occurs. The present paper continues an analysis of flows which either encounter the limiting surface beyond the light cylinder (between the cones of zero axial magnetic field), or do not meet it at all. The formalism introduced by Mestel et aL for the description of the outflow is applied in an extended version which fully incorporates Yo, the emission Lorentz factor of the particles. This treatment removes the singularity of Yo at the stellar poles that occurred in the earlier work: because of a nonuniformity in taking the limit of nonrelativistic injection, full incorporation of Yo acts to keep it finite.

scholarly journals Coronal Loop Mapping to Infer the Best Magnetic Field Models for Active Region Prominences

2013 ◽  
Vol 8 (S300) ◽  
pp. 416-417
Author(s):  
G. Allen Gary ◽  
Qiang Hu ◽  
Jong Kwan Lee
Keyword(s):  
Magnetic Field ◽  
Coronal Loop ◽  
Field Model ◽  
Three Dimensional ◽  
Coronal Loops ◽  
Magnetic Field Model ◽  
Free Parameters ◽  
Field Lines ◽  
Fitness Parameter ◽  
The Magnetic Field

AbstractThis article comments on the results of a new, rapid, and flexible manual method to map on-disk individual coronal loops of a two-dimensional EUV image into the three-dimensional coronal loops. The method by Gary, Hu, and Lee (2013) employs cubic Bézier splines to map coronal loops using only four free parameters per loop. A set of 2D splines for coronal loops is transformed to the best 3D pseudo-magnetic field lines for a particular coronal model. The results restrict the magnetic field models derived from extrapolations of magnetograms to those admissible and inadmissible via a fitness parameter. This method uses the minimization of the misalignment angles between the magnetic field model and the best set of 3D field lines that match a set of closed coronal loops. We comment on the implication of the fitness parameter in connection with the magnetic free energy and comment on extensions of our earlier work by considering the issues of employing open coronal loops or employing partial coronal loop.

scholarly journals Curvature radiation in rotating pulsar magnetosphere

2012 ◽  
Vol 8 (S291) ◽  
pp. 552-554
Author(s):  
P. F. Wang ◽  
C. Wang ◽  
J. L. Han
Keyword(s):  
Magnetic Field ◽  
Circular Polarization ◽  
Field Line ◽  
Pulsar Magnetosphere ◽  
Curvature Radiation ◽  
Line Region ◽  
Open Field Line ◽  
Polarized Emission ◽  
Field Lines ◽  
Relativistic Particles

AbstractWe investigate the curvature radiation from relativistic particles streaming along magnetic field lines and co-rotating with a pulsar. The co-rotation affects the trajectories of the particles and hence the emission properties, especially the polarization. For three density models in the form of core, cone and patches, we calculate the polarized emission at a given height and also the integrated emission for the whole open field line region, and try to explain the generation of circular polarization.

scholarly journals Equilibrium of the Return-Current Sheet and Structure of the Pulsar Magnetosphere

1992 ◽  
Vol 128 ◽  
pp. 112-113
Author(s):  
Yu. E. Lyubarskii
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Neutron Stars ◽  
Current Sheet ◽  
Equilibrium Condition ◽  
Pulsar Magnetosphere ◽  
Field Lines ◽  
Current Flows ◽  
Magnetic Poles ◽  
Open Magnetic Field

Pulsars are generally identified with rotating, magnetized neutron stars. According to Goldreich and Julian (1969), an induced electric field creates the electric current which flows out of the magnetic poles and fills the magnetosphere with plasma. The current flows along the open magnetic field lines and returns along the boundary between the closed and open parts of the magnetosphere (Scharlemann and Wagoner 1973). The boundary shape is determined by the equilibrium condition for the current sheet.

scholarly journals On the thermal effects on radio waves propagating in the pulsar magnetosphere

2021 ◽  
Vol 87 (1) ◽  
Author(s):  
A. G. Mikhaylenko ◽  
V. S. Beskin ◽  
Ya. N. Istomin
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Thermal Effects ◽  
Electromagnetic Waves ◽  
Radio Waves ◽  
Pulsar Magnetosphere ◽  
Dispersion Properties ◽  
Field Lines

Thermal effects on the properties of four electromagnetic waves propagating in the pulsar magnetosphere are analysed. It is shown that thermal effects change only quantitatively the dispersion properties of superluminal ordinary O-mode freely escaping the pulsar magnetosphere; whereas properties of the extraordinary X-mode remain unchanged. The research shows that for two subluminal waves propagating along magnetic field lines thermal effects result in essential absorption. However, this attenuation occurs at considerable distances from the neutron star, and there is no doubt of their existence.

Stochastic magnetic field lines diffusion in a toroidal configuration (Tokamak)

2000 ◽  
Vol 12 (2) ◽  
pp. 145-153 ◽  
Author(s):  
R. Tabet ◽  
H. Imrane ◽  
D. Saifaoui ◽  
A. Dezairi ◽  
F. Miskane
Keyword(s):  
Magnetic Field ◽  
Field Lines ◽  
Stochastic Magnetic Field

Exact nonlinear wave solutions of the incompressible magnetohydrodynamic equations in a sheared magnetic field

1990 ◽  
Vol 44 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Hiromitsu Hamabata
Keyword(s):  
Magnetic Field ◽  
Incompressible Fluid ◽  
Large Amplitude ◽  
Uniform Magnetic Field ◽  
Magnetohydrodynamic Equations ◽  
Wave Solutions ◽  
Field Lines ◽  
Incompressible Magnetohydrodynamic Equations ◽  
Physical Quantities ◽  
Nonlinear Wave Solutions

Exact wave solutions of the nonlinear jnagnetohydrodynamic equations for a highly conducting incompressible fluid are obtained for the cases where the physical quantities are independent of one Cartesian co-ordina.te and for where they vary three-dimensionally but both the streamlines and magnetic field lines lie in parallel planes. It is shown that there is a class of exact wave solutions with large amplitude propagating in a straight but non-uniform magnetic field with constant or non-uniform velocity.

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