1991 Fiscal Year Final Research Report Summary
Global Magnetic Fields of Galaxies and Models for the Galactic Centers
| Project/Area Number |
01460009
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Astronomy
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| Research Institution | Faculty of Science, Nagoya University |
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Principal Investigator |
FUJIMOTO Mitsuaki Department of Physics, Nagoya University Professor, 理学部, 教授 (70022580)
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| Co-Investigator(Kenkyū-buntansha) |
SAWA Takefumi Faculty of Education, Aichi University of Education Associate Professor, 教育学部, 助教授 (90111864)
HANAWA Tomoyuki Department of Physics, Nagoya University Research Associate, 理学部, 助手 (50172953)
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| Project Period (FY) |
1989 – 1991
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| Keywords | Galactic Magnetic Field / Accretion Disk / Parker Instability / Galactic Nucleus / Rotating Gaseous Body / Globular Cluster |
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| Research Abstract |
A variety of violent phenomena of the universe and galaxies are due mostly to the coupling among their self-gravity, rotation and magnetic fields. The present research project has been conducted on the basis of this idea, and obtained the following restilts.
1. We have found bisymmetric spiral (BSS) and axisymmetric spiral (ASS) configuration of galactic magnetic fields by applying the IF-araday rotation effect on polarized radio emission. A tlieoretical reproduction of the BSS fields is successfully conducted by introducing the turbulent diffusion and dynamo production of magnetic fields in differentially-rotating disks. According to tlie results, we predicted the halo magnetic field structure of disk galaxies, the magneto-gravitaional interaction between the BSS fields and spiral density waves, and then found a relation between the BSS seed-fields and tlie possible existence of large-scale cosmic magnetic fields.
2. Local analyses are made for a combined effect of Parker's and Jean's instability of magnetized interstellar gas under rotation. We have discussed tlie formation of giant i-nolectilar clouds, and filaments of interstellar gas in the vicinity of star formation regions.
3. We have developed a tecliiiique to display on computer screen the astronomical data that we have obtained numerically. Our motivation is to visualize the digital data so much as possible that we can learn from them intuitively the basic principle. (1) We have visualized tlie hydromagnetic process of the formation of giant molecular clouds and gaseous filaments in star forming regions. (2) We have built a bird's-eye view of galactic magnetic fields and predicted tlie predominant existence of poloidal components in the galactic halo.
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