1994 Fiscal Year Final Research Report Summary
A STUDY ON MECHANISM AND STRUCTURE OF RELATIVISTIC STELLAR WIND FROM ROTATING MAGNETOSPHERES
| Project/Area Number |
05640301
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Astronomy
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| Research Institution | DEPARTMENT OF PHYSICS,YAMAGATA UNIVERSITY |
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Principal Investigator |
SHIBATA Shinpei YAMAGATA UNIVERSITY,DEPARTMENT OF PHYSICS,ASSISTANT PROFESSOR, 理学部, 助手 (90187401)
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| Project Period (FY) |
1993 – 1994
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| Keywords | MAGNETOHYDRODYNAMICS / RELATIVITY / PLASMA ACCELERATION / PULSAR / NEUTRON STAR / SUPER MAGNETOSONIC FLOW |
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| Research Abstract |
The main aim of this project is to clarify the effeciency of acceleration of the relativistic plasma outflow which is ejected from the rotating strongly magnetized objects in space. The efficiency is defined by how much fraction of the electromagnetic energy flux, which is dominant at the root of the stellar wind, is converted into plasma kinetic energy.
At the fisrt year of this project, we approximately solved the magnetic field structure, which is believed to govern the efficiency. This is done by solving the so-called 'Grad-Shafranov' equation. We have obtained the field structure which is like the diple near the star and gradually modifed to the radial-alike open structure.
At the second year, the field-aligned equation is solved under the obtained field structure in orger to get the efficiency. The field-aligned solution is chosed so that it start from the plasma source, passes throught the Alfven-critical point, and then passes throught the fast-critical point. It has been known that if the field structure is perfectly radial and the plasma is cold, then the fast-critical point is at infinity, and the efficiency is quite small. Contrarily, under the field structure we obtained in this project, we find that the fast-critical point moved inward to near the light cylinder, and very hight efficiency is obtained.
Observationary, the relativistic wind from the Crab pulsar shows a high efficiency so our theory may account for this observational result.
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Research Products
(6 results)
