1987 Fiscal Year Final Research Report Summary
Research on Star Formation and Associated Gas DynamicalPhenomena
| Project/Area Number |
60302015
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| Research Category |
Grant-in-Aid for Co-operative Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
Astronomy
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| Research Institution | Kyoto University |
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Principal Investigator |
NAKANO Takenori Faculty of Science, Kyoto University, 理学部, 助教授 (30027346)
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| Co-Investigator(Kenkyū-buntansha) |
MIYAMA Shoken M. Faculty of Science, Kyoto University, 理学部, 助手 (00166191)
FUKUI Yasuo Faculty of Science, Nagoya University, 理学部, 助教授 (30135298)
IKEUCHI Satoru Tokyo Astronomical Observatory, University of Tokyo, 東京天文台, 助教授 (90025461)
KAIFU Norio Tokyo Astronomical Observatory, University of Tokyo, 東京天文台, 助教授 (50011630)
UCHIDA Yutaka Faculty of Science, University of Tokyo, 理学部, 教授 (90012814)
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| Project Period (FY) |
1985 – 1987
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| Keywords | star formation / Protostars / Infrared objects / Bipolar molecular flows / Molecular clouds / 回転ガス雲 / 磁気星間雲 / 銀河磁場 |
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| Research Abstract |
1. Equilibrium structure of rotating interstellar clouds has been investigated and the maximum mass of the cloud in equilibrium has been determined. 2. The stability of rotating clouds has been investigated by following the dynamical evolution of the cloud starting from the equilibrium state and it has been found that the cloud is unstble when the ratio of the semi-major axes exceeds about 4. 3. The dissipation processes of magnetic fields in the interstellar clouds have been investigated and it has been found that the magnetic field is well frozen to the gas at the density n_H 10^<11>cm^<-3>, decouples from the gas at n_H 5x10^<11>cm^<-3>, and recovers the coupling when the temperature T exceeds about 1000K. Therefore, most of the initial magnetic flux of the cloud is lost between the states of n_H 5x10^<11>cm^<-3> and T 1000K. 4. It has been shown that the steady magnetic field is maintained in the spiral galaxy if the effect of turbulent diffusion of magnetic fields is taken into account. 5. By computer simulations of the phenomena around a contracting magnetized cloud with rotation, the bipolar flows similar to the observed ones in the star-forming regions have been found to occur. 6. The propagation of the stellar wind from a star surrounded by a gaseous disk has been investigated intending to derive a bipolar flow. 7. It has been found by the observations of some bipolar molecular flow sources that the flow has a rotational motion and has a shell structure and the central object is accompanied with a rotating disk. 8. Twenty-one bipolar flow objects have been newly found by the survey of some star-forming regions.
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