SUMMARY OF PROPOSAL 51021
OSAKA UNIVERSITY, GRADUATE SCHOOL OF SCIENCE
OSAKA JAPAN 560
TOYONAKA
1-1, MACHIKANEYAMA
Tel: 06-850-5478 Fax: 06-850-5539
Medium: 2.5GB8MM
Subject: STARS
OBSERVATIONAL STUDY OF "COSMIC ABUNDANCE"
ABSTRACT
The metal abundance of stars and SNRs derived from ASCA observation is generally smaller than the so-called "cosmic abundance". We are trying to study this mysterious problem. On early type stars, a simple analysis of ASCA data, assuming a thin thermal plasma model, leads to a poor metal abundance. However, if resonance scattering makes the effective optical depth for the absorption sufficiently large, ASCA data are consistent with the "cosmic abundance". This assumption is based on the three O-stars data by ASCA, whose abundances derived by the simple analysis are surprisingly similar. This arguments on the resonance scattering should be confirmed by more samples of early type stars.
CO-INVESTIGATORS
| CO-I NAME | INSTITUTE | COUNTRY |
|---|
| KEN'ICHI TORII | OSAKA UNIVERSITY | JAPAN |
| SHOUKO TANAKA | OSAKA UNIVERSITY | JAPAN |
| KUMI YOSHITA | OSAKA UNIVERSITY | JAPAN |
TARGETS
| TARGET NAME | PRI | RA | DEC | TIME | TC | OFF | GIS | SIS CNT | OBS |
|---|
| 1)15 MON | 2 | 100.2442 | 9.8957 | 40 ks | N | Y | P | 0.30000 | 1 |
| 2)9 SGR | 2 | 270.9679 | -24.3607 | 40 ks | N | Y | P | 0.10000 | 1 |