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1997 Fiscal Year Final Research Report Summary

THREE DIMENSIONAL STUDY ON PULSAR MAGNETOSPHERE WHICH CREATES ELECTRON-POSITRON PAIRS

Research Project

Project/Area Number 08454047
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Astronomy
Research InstitutionYAMAGATA UNIVERSITY

Principal Investigator

SHIBATA Shinpei  FACULTY OF SCIENCE YAMAGATA UNIVERSITY,Associate Professor, 理学部, 助教授 (90187401)

Project Period (FY) 1996 – 1997
Keywordsparticle acceleration / QED (Quantum electrodynamics) / magnetosphere / pulsar / X-ray / gamma-ray / special porpouse computer / plasma
Research Abstract

Mechanism of particle acceleration in the pulsar magnetosphere is mostly studied in the axisymmetric case because analysis in non-axisymmetric case, i.e., in the case that the magnetic axis is inclined to the rotation axis, is tremendously difficult. This project callenges to this non-aligned case. Note the real pulsar system is indeed non-aligned completely three dimensional system. Although we have to deal with large numerical calculation, we overcome this problem by using a special porpouse computer. The use of a special porpouse computer makes this project distinctive to other works.
(1) In the first step, we analytically study the formation of the field-aligned electric field, which accelerate particles on the polar caps. There are two kind of magnetic field lines : the field lines curving toward the rotation axis and those curving away the rotation axis. It was proposed that acceleration takes place only on the 'toward field lines'. However, I showed that particle acceleration takes place regardless of field line curvature if the current density is larger than a critical value. This acceleration is shown to be strong enough to cause electron-positron pair creation cascade. (Shibata 1997)
(2) In the non-aligned case, there is an effect of the displacement current on the field structure. The convection current also contribute to the field structure. Including the both effects, we calculate the field structure of the perpendicular rotator in the force-free case. (Mestel and Shibata, 1998 in preparation)
(3) I developed a particle-code for the three-dimensional magnetospheric model on the special porpouse computer Harp-3 (2.2Gflops). Hape-3 was original made for gravitationary interacting particles, but we use it for Coulomb interaction. This code will be used to study a electrosphere in which pair creation takes place. This is an important step for the future calculation for particle simulation of the magnetosphere with pair discharge.

  • Research Products

    (12 results)

All Other

All Publications (12 results)

  • [Publications] S., Shibata: "The field-aligned Accelerator in the Pulsar Magnetoshpere" Monthly Notices of Royal Astronomical Society. 287. 262-270 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y., Saito 他: "Detection of Magnetospheric Emission from PSR B1821-24" Astrophycal Journal. 477. L37-L40 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] S., Shibata 他: "X-ray Nebula around the Gamma-ray Pulsar PSR1055-52" Astrophysical Journal. 483. 843-848 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] S., Shibata 他: "On the Electric-Field Screening by electron-positron pairs" Monthly Notices of Royal Astronamical Society. (印刷中). (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M., Takahashi & S., Shibata: "Trans-fast MHD winds in a Pulsar Magnetosphere" Publication of Astronamical Society of Japan. (印刷中). (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] N., Shibazaki 他編: "Neutron Stars and Pulsars" ユニバーサル アカデミープレス, 650 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] S.Shibata: "The field-aligned Accelerator in the Pulsar Magnetosphere" Monthly Notices Roy.Astron.Soc.287. 262-270 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Saito et al.: "Detection of Magnetospheric Emission form PSR B1821-24" Astrophysical Journal. 477. L37-L40 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] S.Shibata et al.: "X-ray Nebula around the Gammaray Pulsar PSR 1055-52" Astrophysical Journal. 483. 843-848 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] S.Shibata et al.: "On the Electric-Field Screening by electron-positron pairs" Monthly Notices Roy.Astron.Soc.(in press).

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] M.Takahashi and S.Shibata: "Trans-fast MHD winds in a Pulsar Magnetosphere" Publication of Astron.Soc.of Japan. (in press).

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] N.Shibazaki et al.: "Neutron Stars and Pulsars". Universal Academy Press Tokyo, Japan, 600 (1998)

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 1999-03-16  

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