Pulsar magnetospheres

Kennel, C. F.; Fujimura, F. S.; Pellat, R.

doi:10.1007/bf00172211

Cited by 10 publications

(11 citation statements)

References 3 publications

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“…This view is obviously related to previous pictures of the mag netosphere, especially those of Sturrock (1971) and of Kennel et al (1979). So far as I know, however, the essential point here is new, except for a brief mention in Paper I.…”

Section: Boundary Conditions For Polar Flowsupporting

confidence: 65%

The Slot Gap Model of Pulsars

Arons¹

1981

Symp. - Int. Astron. Union

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A general picture of pulsar magnetospheres is outlined which suggests polar current flow should proceed within a magnetic flux tube with conducting boundaries. The dynamics of this current flow is considered, including the effect of formation of pair plasma on the potential. A slot gap surrounding the stream of pair plasma is described, and the electric fields and J·E work done in the gap are calculated. The inapplicability of curvature emission to the formation of γ-ray pulses is discussed. The dynamics of pair plasma flow is described, including electrostatic trapping of low energy positrons, polar cap bombardment and heating, and the emission of soft X-rays from the cap. The relation of this current flow and polar cap heating to the formation of fluctuations on the radio subpulse time scale is also described. The importance of the boundary layer between the pair plasma and the slot gap is illustrated by calculations of the boundary layer structure and microscopic instability, which show that this region may be the source of pulsar emission.I will describe a number of quantitative results and qualitative aspects of work in progress on the “slot gap” model for the emission regions of a pulsar, proposed by Arons and Scharlemann (1979, hereafter AS) and by Arons (1979b, hereafter I). The results and ideas concern the dynamics and emission physics of relativistic plasma and current flow along the polar field lines of an isolated, rotating magnetized neutron star with the axis of its dipole moment oblique to the rotation axis - a pulsar. The quantitative modelling is confined to the physics within a polar flux tube and is therefore “local”. Full detail will be given in papers now being written. However, development of this type of model requires the use of boundary conditions which follow from a qualitative view of the whole magnetosphere. Because this view involves some qualitative ideas not widely discussed in the literature, I describe it briefly.

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Section: Boundary Conditions For Polar Flowsupporting

confidence: 65%

The Slot Gap Model of Pulsars

Arons¹

1981

Symp. - Int. Astron. Union

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“…Pair production in the magnetosphere is the key process to determine which regime is to be applied and nothing forbids us from switching from one regime to another during plasma transport towards the nebula. Kennel, Fujimura & Pellat (1979) give orders of magnitude for the properties of these waves and winds. We briefly discuss the evolution of the ideas concerning pulsar magnetospheres which led to these three alternatives.…”

Section: Orders Of Magnitudementioning

confidence: 99%

Theory of pulsar magnetosphere and wind

Pétri

2016

J. Plasma Phys.

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Neutron stars are fascinating astrophysical objects immersed in strong gravitational and electromagnetic fields, at the edge of our current theories. These stars manifest themselves mostly as pulsars, emitting a timely very stable and regular electromagnetic signal. Even though discovered almost fifty years ago, they still remain mysterious compact stellar objects. In this review, we summarize the most fundamental theoretical aspects of neutron star magnetospheres and winds. The main competing models explaining their radiative properties like multi-wavelength pulse shapes and spectra and the underlying physical processes such as pair creation and radiation mechanisms are scrutinized. A global but still rather qualitative picture slowly emerges thanks to recent advances in numerical simulations on the largest scales. However considerations about pulsar magnetospheres remain speculative. For instance, the exact composition of the magnetospheric plasma is not yet known. Is it solely filled with a mixture of e ± leptons or does it contain a non-negligible fraction of protons and/or ions? Is it almost entirely filled or mostly empty except for some small anecdotal plasma filled regions? Answers to these questions will strongly direct the description of the magnetosphere to seemingly contradictory results leading sometimes to inconsistencies. Nevertheless, accounts are given as to the latest developments in the theory of pulsar magnetospheres and winds, the existence of a possible electrosphere and physical insight obtained from related observational signatures of multi-wavelength pulsed emission.

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“…[1][2][3][4][5][6][7][8][9][10][11] The short lifetimes of such electron-positron plasmas, coupled to extremely strong magnetic fields, make for rather uncommon phenomena. On the other hand, experiments on electron-positron plasmas have been performed in rather demanding circumstances, given the ready annihilation of the electrons and the positrons.…”

Section: Introductionmentioning

confidence: 99%

Existence of bulk acoustic modes in pair plasmas

Verheest

2006

Physics of Plasmas

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In view of applications to electron-positron and fullerene pair plasmas, a thorough discussion is given of the dispersion of linear electrostatic waves, before finding the parameter ranges in which stationary nonlinear electrostatic modes can exist, when there is a thermodynamic asymmetry between both constituents. Arguments for such an asymmetry can be found in the observed dispersion in fullerene pair plasma experiments, but point to small asymmetries. The existence of solitary modes is first discussed in general terms for various polytropic pressure-density relations, showing that the solitons are always compressive in both pair components. For large thermal asymmetries, there is at most a doubling of the densities, but small asymmetries lead to weakly nonlinear amplitudes, described by familiar Korteweg-de Vries solitons. Observations of an intermediate wave in the theoretical gap between the acoustic and Langmuir branches of the linear dispersion diagram might be accounted for, at least partially, by a train of weak solitons, as the difference between weak solitary modes and linear harmonic waves is rather difficult to ascertain experimentally.

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Pulsar magnetospheres

Cited by 10 publications

References 3 publications

The Slot Gap Model of Pulsars

The Slot Gap Model of Pulsars

Theory of pulsar magnetosphere and wind

Existence of bulk acoustic modes in pair plasmas

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