| Project/Area Number |
05640312
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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 | The University of Tokyo |
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Principal Investigator |
SUTO Yasushi The University of Tokyo, Graduate School of Science, Associate Professor, 大学院・理学系研究所, 助教授 (20206569)
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| Co-Investigator(Kenkyū-buntansha) |
ITOH Makoto Kyoto University, Educational Center for Information Processing, Research Associ, 情報処理教育センター, 助手 (00243080)
YAMADA Shoichi The University of Tokyo, Graduate School of Science, Research Associate, 大学院・理学系研究所, 助手 (80251403)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1994: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1993: ¥900,000 (Direct Cost: ¥900,000)
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| Keywords | Proto-galaxy / Clusters of galaxies / Observational cosmology / Numerical simulation / Supernova / 粒子法 |
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| Research Abstract |
The prinicpal goal of the present project is to develop a cosmological hydrodynamic code which is indispensible in quantitatively examining the evolution of proto-galaxies and proto-clusters, and to construct a theoretical model which can approach the above problem in a analytical and complementary manner. To be more specific, the results of our research are summarized as follows :
(1) We have written up a cosmological code which is based on the smoothed particle hydrodynamic method and can properly take into account the gas-radiative processes.
(2) We have derived analytical expressions for formation and destruction rates of gravitationally bound objects. Combining with the nonlinear spherical model, we computed the thermal bremsstrahlung spectrum emitted from individual proto-clusters of galaxies, and then made theoretical predictions of the cosmic X-ray background flux and spectrum due to the clusters of galaxies.
(3) While the recent discovery of the Cepheid variables in the Virgo clu
… More
ster galaxies puts additional support for the Hubble constant H_0 - 80km/sec/Mpc, a relatively lower value H_0 - 50km/sec/Mpc is suggested by other distance indicators. In order to explore an idea that locally determined H_0 is significantly different from its global average, we considered a model of a locally open universe embedded in the spatially flat universe. We found analytic expressions for the lower limit on the global Hubble constant, and the upper limit on the age of the universe with a given value for the Hubble constant in the local universe.
We calculated the gravitational wave form from a rotationally collapsing supernova core. Comparing the results for various angular momentum distributions, we found that LIGO can detect such a signal provided that a rotating supernova occurs in our galaxy. On the other hand, we have developed a new general relativistic hydrodynamics code in which spherical symmetry is assumed and fully implicit scheme is adopted. We think this code is useful to study the delayd mechanism. Less
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