1996 Fiscal Year Final Research Report Summary
Theory of Active Galactic Nuclei
| Project/Area Number |
06452024
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | TOKYO METROPOLITAN UNIVERSITY |
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Principal Investigator |
TAKAHARA Fumio Faculty of Science, TOKYO METROPOLITAN UNIVERSITY,Professor, 理学部, 教授 (20154891)
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| Co-Investigator(Kenkyū-buntansha) |
MASAI Kuniaki Faculty of Science, TOKYO METROPOLITAN UNIVERSITY,Assistant Professor, 理学部, 助教授 (80181626)
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| Project Period (FY) |
1994 – 1996
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| Keywords | Active Galaxies / Relativistic Jets / Particle Acceleration / Gamma-Ray Astronomy / X-Ray Astronomy / Radiative Transfer / Accretion Disks / Black Holes |
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| Research Abstract |
1) We have developed the numerical code which self-consistently solves the vertical structure of and emission spectrum from accretion disks. Numerical results are compared with observations of soft X-ray excess and UV bump of active galactic nuclei. We showed that observations are reproduced for nearly Eddington accretion. We also showed that hard X-ray emission is explained by a hot corona.
2) We showed that gamma-ray emission from blazars is successfully interpreted in terms inverse Compton scattering. We determined electron spectrum consistent with shock acceleration theory, estmated physical quantities of the jets. We argued that energy density of particles dominates that of magnetic fields and that jet plasma most likely consists of electron-positron pairs. Gamma-ray emission was shown to occur at the distance of 100 to 1000 Schwarzschild radii from the central black hole. These results give an important clue to the bulk acceleration mechanism of jets.
3) We studied diffusive particle acceleration by shock waves, especially oblique shocks by the Monte Carlo method. We have shown that acceleration time scale is significantly shortened compared with parallel shocks.
4) We studied atomic and plasma processes which are important in diagnosing the physical states of hot gas in active galactic nuclei. We have applied them to various astrophysical objects.
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