Studies of Accretion Flow onto a Neutron Star
Grant-in-Aid for General Scientific Research (B)
|Allocation Type||Single-year Grants |
|Research Institution||Rikkyo University |
HOSHI Reiun Rikkyo University, Department of Physics, Professor, 理学部, 教授 (70062601)
INOUE Hajime Institute of Space and Astronautical Science, Associate Professor, 助教授 (40092142)
SHIBAZAKI Noriaki Rikkyo University, Department of Physics, Associate Professor, 理学部, 助教授 (50206124)
満田 和久 宇宙科学研究所, 助手 (80183961)
|Project Period (FY)
1989 – 1990
Completed (Fiscal Year 1990)
|Budget Amount *help
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1990: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1989: ¥1,900,000 (Direct Cost: ¥1,900,000)
|Keywords||QPO / X-Ray Star / Mass Accretion|
We have studied the energy spectral properties and quasi-periodic oscillations (QPO) of X-ray intensities especially from the low mass binary X-ray stars. We have proceeded an investigation performing an intimate interplay between theory and observation. We have obtained the following important results from Ginga observations :
(1) a discovery of noncorrelated variation in power between the horizontal branch QPO and the low frequency noise
(2) detectins of QPOs from X-ray pulsars Cen X-3 and 4U 1626-67
(3) a discovery of a shallow and broad absorption feature in the 7-20 keV range of the energy spectrum of 4U 1608-522
(4) a detection of 2-6 Hz QPOs from X-ray transient GS 1124-68
The main results of theoretical studies are summarized as follows :
(1) Conducting a shot noise simulation, we found that the plasma clump-magnetic field interaction used in the beat frequency model cannot explain the observed fact (1).
(2) QPO of X-ray pulsars may be interpreted as a beat frequency intensity modulation.
(3) A shallow broad absorption structure in the energy spectra may be due to the reflection of a part of X-rays from the neutron star surface in the outer part of the disk.
(4) The low frequency QPOs as observed from GS 1124-68 may be due to the waves excited in the accretion disk.
Our studies here provided us with an important basis to understand the accretion flow onto a neutron star. More studies should be done to elucidate the detailed properties of the accretion flow.
Report (3 results)
Research Products (88 results)