1997 Fiscal Year Final Research Report Summary
Cosmic Chemical Evolution Based on the Hierarchical Galaxy Formation Scenario
| Project/Area Number |
08640336
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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 | National Astronomical Observatory |
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Principal Investigator |
TSUJIMOTO Takuji Astrometry and Celestial Mecahanics Division, 位置天文・天体力学研究系, 助手 (10270456)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Supernova / Initial Mass Function |
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| Research Abstract |
Oxygen to iron abundance ratios of metal-poor stars provide information on nucleosynthesis yields from massive stars which end in Type II supernova explosions. Using a standard model of chemical evolution of the Galaxy we have reproduced the solar neighborhood abundance data and estimated the oxygen and iron yields of genuine SN II origin. The estimated yields are compared with the theoretical yields to derive the relation between the lower and upper mass limits in each generation of stars and the IMF slope. Independently of this relation, we furthermore derive the relation between the lower mass linit and the IMF slope from the stellar mass to light ratio in the solar neighborhood. These independent relations unambiguously determine the upper mass limit of m<@D2u@>D2=50(]SY.+-。[)10 M<@D2(]SY.sun.[)@>D2 and the IMF slope index of 1.3-1.6 above 1 M<@D2(]SY.sun.[)@>D2. This upper mass limit corresponds to the mass beyond which stars end as black holes without ejecting processed matter into the interstellar medium. we also find that the IMF slope index below 0.5 M<@D2(]SY.sun.[)@>D2 cannot be much shallower than 0.8.
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Research Products
(4 results)
