| Project/Area Number |
03640391
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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 |
Space and upper atmospheric physics
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| Research Institution | University of Tokyo |
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Principal Investigator |
NAKAGAWA Yositsugu Univ. of Tokyo, Faculty of Science, Research Associate., 理学部, 助手 (30172282)
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| Co-Investigator(Kenkyū-buntansha) |
SEKIYA Minoru Teikyo Univ., Dept. of Mechanical and Precision System, Instructor., 理工学部, 講師 (60202420)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1992: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1991: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | solar system origin / primitive solar nebula / solar nebula / protoplanetary disks / dust opacity / shear instability / T Tauri stars / gravitational instability / 原始惑星系円盤 / ダスト / Tタウリ型星 / 太陽系 / ガスーダスト円盤 |
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| Research Abstract |
For these two years we studied formation and evolution of the solar nebula. Our research consists of the following these studies: (i) Over-reflection and over-transmission of non-axisymmetric waves in differentially rotating disks with self-gravity, (ii) Formation and early evolution of the solar nebula, (iii) Effect of particle growth on opacity curves of protoplanetary disks around T Tauri stars. We give brief summaries of these studies below.
Study(i): We quantitatively clarified phenomena of over-reflection and over-transmission of non- axisymmetric waves in differentially rotating disks and found that the self-gravity of the disks enhances these phenomena quite efficiently. These phenomena are considered as one of excitation mechanism of turbulence, and turbulence causes early evolution of the solar nebula.
Study(ii): We numerically simulated the processes of formation and early evolution of the solar nebula. We obtained radial temperature distribution in the solar nebula which is consistent with observation of protoplanetary disks around T Tauri stars. The temperature distribution is kept by surface heating due to infall gas and by viscous heating in the nebula. We also found that in the gas infall phase the solar nebula becomes gravitationally unstable at a radial distance comparable to the size of the present solar system.
Study(iii): We showed that dust growth in protoplanetary disks can quite naturally explain the diffrences in opacity between dust in protoplanetary disks and interstellar dust. We also showed that the opacity of grown dust gives an estimate of disk mass consistent with nominal solar nebula models.
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