Pulsed radiation from neutron star winds

Kirk, J. G.; Skjæraasen, O.; Gallant, Y. A.

doi:10.1051/0004-6361:20020599

Cited by 94 publications

(103 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the latter case extracting the pulsed component from the total data would be misleading. Possibly the wind model by Kirk et al (2002) offers an example for a source of radiation which produces fixed position angle at all phases except from those at which the peaks occur. In the model, high-energy radiation is emitted at large distances from the star (10−100R lc ) at current sheets, which separate "layers" of the toroidal magnetic field.…”

Section: Discussionmentioning

confidence: 99%

Relativistic Effects and Polarization in Three High‐Energy Pulsar Models

Dyks

Harding

Rudak

2004

ApJ

211

292

View full text Add to dashboard Cite

We present the influence of the special relativistic effects of aberration and light travel time delay on pulsar high-energy lightcurves and polarization characteristics predicted by three models: the two-pole caustic model, the outer gap model, and the polar cap model. Position angle curves and degree of polarization are calculated for the models and compared with the optical data on the Crab pulsar. The relative positions of peaks in gamma-ray and radio lightcurves are discussed in detail for the models. We find that the two-pole caustic model can reproduce qualitatively the optical polarization characteristics of the Crab pulsar -fast swings of the position angle and minima in polarization degree associated with both peaks. The anticorrelation between the observed flux and the polarization degree (observed in the optical band also for B0656+14) naturally results from the caustic nature of the peaks which are produced in the model due to the superposition of radiation from many different altitudes, ie. polarized at different angles. The two-pole caustic model also provides an acceptable interpretation of the main features in the Crab's radio profile. Neither the outer gap model nor the polar cap model are able to reproduce the optical polarization data on the Crab. Although the outer gap model is very successful in reproducing the relative positions of gamma-ray and radio peaks in pulse profiles, it can reproduce the high-energy lightcurves only when photon emission from regions very close to the light cylinder is included.

show abstract

Section: Discussionmentioning

confidence: 99%

Relativistic Effects and Polarization in Three High‐Energy Pulsar Models

Dyks

Harding

Rudak

2004

ApJ

211

292

View full text Add to dashboard Cite

show abstract

“…Explaining pulsation by such a mechanism was already suggested at the beginning era of pulsar theory as proposed by Michel (1971) and . These ideas have been reinvestigated more recently by Kirk et al (2002). These studies showed that the striped wind is a possible site for generation of incoherent high-energy radiation, going from optical up to gamma rays.…”

Section: J Pétrimentioning

confidence: 99%

Theory of pulsar magnetosphere and wind

Pétri

2016

J. Plasma Phys.

View full text Add to dashboard Cite

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.

show abstract

“…We use an explicit asymptotic solution for the large-scale field structure related to the oblique split monopole and valid for the case of an ultrarelativistic plasma (Bogovalov 1999). Due to relativistic beaming effects, it has already been shown that this model gives rise to pulsed emission (Kirk et al 2002) and can satisfactorily fit the optical polarization data from, for instance, the Crab pulsar (Pétri & Kirk 2005).…”

Section: Introductionmentioning

confidence: 82%

High-energy pulses and phase-resolved spectra by inverse Compton emission in the pulsar striped wind

Pétri

2009

A&A

View full text Add to dashboard Cite

Context. Although discovered 40 years ago, the emission mechanism responsible for the observed pulsar radiation remains unclear. However, high-energy pulsed emission is usually explained in the framework of either the polar cap or the outer gap model. Here we explore an alternative model based on the striped wind. Aims. The purpose of this work is to study the pulsed component, the light-curves as well as the spectra of the high-energy emission, above 10 MeV, emanating from the striped wind model. Gamma rays are produced by scattering off the soft cosmic microwave background photons on the ultrarelativistic leptons flowing in the current sheets. Methods. We compute the time-dependent inverse Compton emissivity of the wind, in the Thomson regime, by performing threedimensional numerical integration in space over the whole striped wind. The phase-dependent spectral variability is then calculated as well as the change in pulse shape when going from the lowest to the highest energies. Results. Several light curves and spectra of inverse Compton radiation with phase resolved dependence are presented. We apply our model to the well-known gamma-ray pulsar Geminga. We are able to fit the EGRET spectra between 10 MeV and 10 GeV as well as the light curve above 100 MeV with good accuracy. Conclusions. In the striped wind model, the pulses are a direct consequence of the relativistic beaming effect. It is a simple geometrical model able to explain the very high-energy variability of the phase-resolved spectrum as well as the shape of the associated pulses. Future comparisons with observations at the highest energies and possibly polarization measurements will be important to discriminate between existing models.

show abstract

Pulsed radiation from neutron star winds

Cited by 94 publications

References 23 publications

Relativistic Effects and Polarization in Three High‐Energy Pulsar Models

Relativistic Effects and Polarization in Three High‐Energy Pulsar Models

Theory of pulsar magnetosphere and wind

High-energy pulses and phase-resolved spectra by inverse Compton emission in the pulsar striped wind

Contact Info

Product

Resources

About