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Title: Generation of pulsed emission from rotating neutron stars by plasma streaming instabilities. [Mechanisms, electron-positron beam, magnetosphere, collective effects]

Abstract

Collective effects caused by a high energy electron-positron beam traversing a low energy electron-positron plasma are investigated for a range of parameters appropriate to pulsar magnetospheres. The different instabilities that can result from such a particle distribution and the resultant instabilities that may be of importance along the open magnetic field lines inside the star's rotational speed of light cylinders are identified. The analysis suggests that two instabilities may be of importance in the production of pulsed emission. If the initial particle distribution is of a two-stream type then there exists an electrostatic instability and an associated transverse wave provided the cyclotron frequency is much larger than the plasma frequency. The group velocity is along the ambient magnetic field and it is suggested that the observed radio pulses from pulsars may be caused by the focusing of these transverse waves along the open field lines extending from a pulsar's polar cap to the light cylinder. A second instability associated with the ordinary mode and sometimes referred to as the Weibel instability may also be important in pulsar magnetospheres. Although independent of the exact shape of the particle distribution a requirement for the ordinary mode to become unstable is that themore » particle energy density exceed the magnetic tension B/sup 2//4..pi... This instability generates a magnetic field component perpendicular to the ambient magnetic field and scatters particles in pitch angle. The resultant synchrotron emission provides a plausible physical basis for the origin of optical, x-ray and ..gamma..-ray pulses from the Crab pulsar. Evolution of a synchrotron spectrum produced by this mechanism suggests that only in very young pulsars would optical pulses exist at intensities that could be detected observationally.« less

Authors:
Publication Date:
Research Org.:
Maryland Univ., Baltimore (USA)
OSTI Identifier:
7221632
Resource Type:
Thesis/Dissertation
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CRAB NEBULA; EMISSION SPECTRA; NEUTRON STARS; PULSARS; KINETICS; MAGNETOSPHERE; PLASMA INSTABILITY; ROTATION; SYNCHROTRON RADIATION; BREMSSTRAHLUNG; COSMIC RADIO SOURCES; EARTH ATMOSPHERE; ELECTROMAGNETIC RADIATION; INSTABILITY; MOTION; NEBULAE; RADIATIONS; SPECTRA; STARS; SUPERNOVA REMNANTS; 640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar, Radio & X-Ray Sources; 640103 - Astrophysics & Cosmology- Quasi-Stellar, Radio, & X-Ray Sources- (-1987)

Citation Formats

Hardee, P E. Generation of pulsed emission from rotating neutron stars by plasma streaming instabilities. [Mechanisms, electron-positron beam, magnetosphere, collective effects]. United States: N. p., 1976. Web.
Hardee, P E. Generation of pulsed emission from rotating neutron stars by plasma streaming instabilities. [Mechanisms, electron-positron beam, magnetosphere, collective effects]. United States.
Hardee, P E. 1976. "Generation of pulsed emission from rotating neutron stars by plasma streaming instabilities. [Mechanisms, electron-positron beam, magnetosphere, collective effects]". United States.
@article{osti_7221632,
title = {Generation of pulsed emission from rotating neutron stars by plasma streaming instabilities. [Mechanisms, electron-positron beam, magnetosphere, collective effects]},
author = {Hardee, P E},
abstractNote = {Collective effects caused by a high energy electron-positron beam traversing a low energy electron-positron plasma are investigated for a range of parameters appropriate to pulsar magnetospheres. The different instabilities that can result from such a particle distribution and the resultant instabilities that may be of importance along the open magnetic field lines inside the star's rotational speed of light cylinders are identified. The analysis suggests that two instabilities may be of importance in the production of pulsed emission. If the initial particle distribution is of a two-stream type then there exists an electrostatic instability and an associated transverse wave provided the cyclotron frequency is much larger than the plasma frequency. The group velocity is along the ambient magnetic field and it is suggested that the observed radio pulses from pulsars may be caused by the focusing of these transverse waves along the open field lines extending from a pulsar's polar cap to the light cylinder. A second instability associated with the ordinary mode and sometimes referred to as the Weibel instability may also be important in pulsar magnetospheres. Although independent of the exact shape of the particle distribution a requirement for the ordinary mode to become unstable is that the particle energy density exceed the magnetic tension B/sup 2//4..pi... This instability generates a magnetic field component perpendicular to the ambient magnetic field and scatters particles in pitch angle. The resultant synchrotron emission provides a plausible physical basis for the origin of optical, x-ray and ..gamma..-ray pulses from the Crab pulsar. Evolution of a synchrotron spectrum produced by this mechanism suggests that only in very young pulsars would optical pulses exist at intensities that could be detected observationally.},
doi = {},
url = {https://www.osti.gov/biblio/7221632}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Jan 01 00:00:00 EST 1976},
month = {Thu Jan 01 00:00:00 EST 1976}
}

Thesis/Dissertation:
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