2003 Fiscal Year Final Research Report Summary
Link between protoplanetary materials and interstellar dust
| Project/Area Number |
13440059
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Astronomy
|
|---|
| Research Institution | Nagoya University |
|---|
Principal Investigator |
YAMAMOTO Tetsuo Nagoya Univ., Dept.Earth & Planet, Professor, 大学院・環境学研究科, 教授 (10126196)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KOZAWA Takeshi Hokkaido Univ., Dept.Earth & Planet, Professor, 大学院・理学圏研究科, 教授 (90263368)
WATANABE Sei'ichiro Nagoya Univ., Dept.Earth & Planet, Professor, 大学院・環境学研究科, 助教授 (50230967)
HIRAYAMA Yasuhiro Nagoya Univ., Dept.Earth & Planet, Professor, 大学院・環境学研究科, 助教授 (30252224)
|
|---|
| Project Period (FY) |
2001 – 2003
|
| Keywords | Nucleation / cosmic dust / interstellar matter / meteorites / planets / protoplanetary materials / material evolution in space |
|---|
| Research Abstract |
The carrier of the 21-micron-band observed in the post-AGB stars is examined. We analyze the infrared spectra of the TiC clusters measured by von Helden et al. (2000, Science, 288, 313) and determine the absorption efficiency Q in the 21-micron-band. Using the Q, we estimate the Ti/Si abundance ratios needed to realize the flux ratios of the 21-and 11-micron emissions observed in the infrared spectra of the post-AGB stars exhibiting both 21-and 11-micron emissions. In view of the nature of the TiC condensation that TiC grains are quickly mantled by graphite, we calculate the emission spectra of the graphite-coated TiC grains and other possible types of core-mantle grains, and compare with the observed spectra. Both of the abundance and condensation considerations strongly suggest that TiC is an implausible carrier of the observed infrared 21-micron feature around carbon-rich post-AGB stars.
The following relevant study has also been carried out :
(1) Laboratory spectrosocpic study of molecular clusters,
(2) Review of the role of dust in formation of the planets
|
