Gamma-ray spectra from a polar-cap model of pulsars

AbstractWithin the framework of a single polar cap model we calculate the energy dependence of phase separation between two peaks in the gamma-ray lightcurve of the Vela pulsar. Results are confronted with EGRET data (Kanbach 1999).

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Pulse profiles and spectra of gamma ray pulsars in the polar cap model

Advances in Space Research ◽

10.1016/s0273-1177(97)00811-9 ◽

1998 ◽

Vol 21 (1-2) ◽

pp. 251-254 ◽

Cited By ~ 12

Author(s):

Alice K Harding ◽

Joseph K Daugherty

Keyword(s):

Gamma Ray ◽

Polar Cap ◽

Cap Model

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HINTS ON PULSAR ELECTROMAGNETIC ENERGY LOSSES FROM COSMIC-RAY POSITRON OBSERVATIONS

International Journal of Modern Physics A ◽

10.1142/s0217751x05029964 ◽

2005 ◽

Vol 20 (29) ◽

pp. 6735-6738 ◽

Cited By ~ 1

Author(s):

CATIA GRIMANI

Keyword(s):

Gamma Ray ◽

Cosmic Ray ◽

High Energy ◽

Electromagnetic Energy ◽

Energy Losses ◽

Gap Model ◽

Polar Cap ◽

Preliminary Results ◽

Positron Flux ◽

Cap Model

We present preliminary results of the estimate of isolated pulsar contribution to the positron and electron interstellar fluxes when a polar cap model is assumed. Pulsars of all ages outside their host remnants have been considered. Cosmic-ray positron observations above a few GeV seem to indicate that an outer gap model is favoured over a polar cap model when the contribution of young pulsars only is taken into account. Here we show that pulsars with ages ranging between 10 kyr and 600 kyr, escaped from their remnants, give a contribution to the interstellar positron flux larger than that proposed in literature for the whole sample of pulsars younger than 10 kyr. Consequently, this result also indicates that outer gap electromagnetic energy losses overcome those at the polar cap. Future, low error e+/(e+ + e-) ratio observations as well as high energy pulsed gamma-ray measurements will allow us to verify this possibility.

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The influence of small-scale magnetic field on the heating of J0250+5854 polar cap

Journal of Physics Conference Series ◽

10.1088/1742-6596/2103/1/012034 ◽

2021 ◽

Vol 2103 (1) ◽

pp. 012034

Author(s):

D P Barsukov ◽

A A Matevosyan ◽

I K Morozov ◽

A N Popov ◽

M V Vorontsov

Keyword(s):

Magnetic Field ◽

Steady State ◽

Bound State ◽

Small Scale ◽

Polar Cap ◽

Electron Positron ◽

Curvature Radiation ◽

Cap Model ◽

Star Surface ◽

Primary Electrons

Abstract The influence of surface small-scale magnetic field on the heating of PSR J0250+5854 polar cap is considered. It is assumed that the polar cap is heated only by reverse positrons accelerated in pulsar diode. It is supposed that pulsar diode is located near the star surface (polar cap model) and operates in the steady state space charge-limited flow regime. The reverse positron current is calculated in the framework of two models: rapid and gradually screening. To calculate the production rate of electron-positron pairs we take into account only the curvature radiation of primary electrons and its absorption in magnetic field. It is assumed that some fraction of electron-positron pairs may be created in bound state that can later be photoionized by thermal photons from star surface.

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Magnetic field distribution in polar CAP models of gamma-ray bursters

The Astrophysical Journal ◽

10.1086/169076 ◽

1990 ◽

Vol 359 ◽

pp. 438

Author(s):

Z. Bagoly ◽

P. Meszaros ◽

S. M. Matz

Keyword(s):

Magnetic Field ◽

Field Distribution ◽

Gamma Ray ◽

Magnetic Field Distribution ◽

Polar Cap

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Full Polar Cap Cascade Scenario: Gamma‐Ray and X‐Ray Luminosities from Spin‐powered Pulsars

The Astrophysical Journal ◽

10.1086/308598 ◽

2000 ◽

Vol 532 (2) ◽

pp. 1150-1171 ◽

Cited By ~ 147

Author(s):

Bing Zhang ◽

Alice K. Harding

Keyword(s):

Gamma Ray ◽

Polar Cap ◽

X Ray

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Quiescent Magnetar Emission: Resonant Compton Upscattering

Symposium - International Astronomical Union ◽

10.1017/s0074180900181136 ◽

2004 ◽

Vol 218 ◽

pp. 267-270

Author(s):

Matthew G. Baring

Keyword(s):

Compton Scattering ◽

Gamma Ray ◽

Stellar Surface ◽

X Rays ◽

Polar Cap ◽

Inverse Compton Scattering ◽

Strong Fields ◽

Inverse Compton ◽

Gamma Ray Emission

A principal candidate for quiescent non-thermal gamma-ray emission from magnetars is resonant inverse Compton scattering in the strong fields of their magnetospheres. This paper outlines expectations for such emission, formed from non-thermal electrons accelerated in a pulsar-like polar cap potential upscattering thermal X-rays from the hot stellar surface. The resultant spectra are found to be strikingly flat, with fluxes and strong pulsation that could be detectable by GLAST.

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