2005 Fiscal Year Final Research Report Summary
Theoretical study for the fundamental physical processes of the star formation in proto-galactic clouds and the formation of cosmological first luminous objects.
| Project/Area Number |
14540227
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Astronomy
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| Research Institution | Niigata University |
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Principal Investigator |
NISHI Ryoichi Niigata University, Institute of Science and Technology, Associate Professor -> 新潟大学, 自然科学系, 助教授 (80252419)
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| Project Period (FY) |
2002 – 2005
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| Keywords | galaxy formation / star formation / primordial gas / cosmology |
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| Research Abstract |
We investigated on the formation process of early cosmological luminous objects and discussed them for the observational corroboration of physical scenarios. Firstly, we studied the star formation process in the primordial gas, and estimate the emission line luminosities of H_2 and HD molecules, which are important because they are expected to characterize the primordial star formation process. For the formation process of the first generation stars, HD is not important. But for the star formation in the massive proto-galactic clouds, HD plays important roles as coolant. LiH molecule never plays important role. Secondly, we studied the evolution of the filamentary clouds, which is formed via the fragmentation process of the proto-galactic clouds and important for the formation of the star forming core. In the collapse and the fragmentation processes, the fraction of the dark matter component is very significant. Considering the filaments formed in the gravitational potential well, it is impossible to collapse enough before fragmentation. Thus, efficient star formation is expected to be impossible. We also estimated the emission line luminosities of H_2 and HD molecules for the filaments without dark matter, which are the mother objects of the star formation cores. Finally, estimating the primordial star formation rate in the proto-galactic clouds, we discuss the observational possibility of the formation process of early cosmological luminous objects. Because of the redshift effects, it is important to observe mid-infrared radiation. Thus, SPICA (Space Infrared Telescope for Cosmology and Astrophysics) has the best chance for the observational corroboration in the next generation facilities. If the star formation rate in the primordial gas is as large as the star forming rate of the usual star burst galaxies, SPICA can observe the primordial molecular lines from the first forming process of early cosmological luminous objects.
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Research Products
(7 results)
