1999 Fiscal Year Final Research Report Summary
X-ray spectroscopic study for the evolution of hot plasmas in galaxies and clusters of galaxies
| Project/Area Number |
08404010
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Astronomy
|
|---|
| Research Institution | TOKYO METOROPOLITAN UNIVERSITY |
|---|
Principal Investigator |
OHASHI Takaya Tokyo Metropolitan University, Dpt. of Physics, Professor, 理学研究科, 教授 (70183027)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
ISHISAKI Yoshitaka Tokyo Metropolitan University, Dpt. of Physics, Research Associate, 理学研究科, 助手 (10285091)
YAMASAKI Noriko Tokyo Metropolitan University, Dpt. of Physics, Research Associate, 理学研究科, 助手 (20254146)
MASAI Kuniaki Tokyo Metropolitan University, Dpt. of Physics, Associate Professor, 理学研究科, 助教授 (80181626)
|
|---|
| Project Period (FY) |
1996 – 1999
|
| Keywords | X-ray astronomy / galaxies / clusters of galaxies / hot plasmas / a detector of X-ray |
|---|
| Research Abstract |
The purpose of this research was to understand the formation and evolution process of hot gas in elliptical galaxies and in clusters of galaxies based on X-ray spectroscopic observations mainly from ASCA, and also to develop X-ray detectors with an energy resolution better than 10 eV for new X-ray mission including ASTRO-E. Theoretical study of the plasma processes was also carried out because of its close connection in understanding the X-ray spectral data. Main achievements in the individual research area are summarized as follows.
1. ASCA observations: Spatial distributions of temperature and metal abundance were obtained for near-by bright clusters. Large scale abundance gradient indicated metal production in galaxies, and presence of hot regions in the clusters outskirts showed recent occurrence of mergers with subclusters. Metallicity in elliptical galaxies were determined to be about 1 solar, and greatly extended X-ray emission was discovered around bright galaxies.
2. Theoretical study: Fe-L emission process has been examined and there exists and uncertainty of 30% in the abundance determination. Emission process from recombining plasmas were studied in detail and spectral difference from collisionally ionizing plasmas were compared.
3. Hardware development: Calibrations of microcalorimeters on-board ASTRO-E were carried out and various detector properties were examined and included in the response function. Development of transition edge sensors for a future X-ray mission was carried out. Thermal properties of Mo-Au bilayers were studied, and a readout system of SQUID signals cooled in a dilution refrigerator has been developed.
|
Research Products
(12 results)
