1997 Fiscal Year Final Research Report Summary
Formation and Structure of High-z quasars
| Project/Area Number |
08640329
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | KYOTO UNIVERSITY |
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Principal Investigator |
MINESHIGE Shin KYOTO UNIVERSITY,Graduate School of Science Associate Prefessor, 大学院・理学研究科, 助教授 (70229780)
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| Co-Investigator(Kenkyū-buntansha) |
UMEMURA Masayuki University of Tsukuba, School of Physics Associate Professor, 物理学系, 助教授 (70183754)
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| Project Period (FY) |
1996 – 1997
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| Keywords | quasar / black hole / accretion disks / radiation drag / gravitational instunility / self-similar solutious |
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| Research Abstract |
According to the standard scenario for structural formation, rotating dark-matter disks with mass of about 10^7 solar masses are expected to form at high red-shifts (z-several hundreds). Whether such disks would evolve to quasars depend on later disk evolution. To discuss the disk evolution under the influence of viscosity and selt-gravity, we have seeked for self-similar solutions and could find them. We have also examined how Compton drag due to background radiation affect viscous disk evolution, finding that drag and viscosity actually reinforce each other, thereby rapid disk collapse being promoted. Now the possibility to form a proto-quasar black hole by such a massive self-gravitating disk has become realistic.
We have also found a novel method to observationally resolve the central structure of high redshift quasars. This is to use the so-called gravitational microlensing ; namely, when stars pass by the image of a quasar, radiation from a tiny portion will selectively be amplified. We have in fact apply this method to Einstein Cross (Q02237), finding that emission properties of the disk around a putative black hole will be resolved on spatial scales down to several Schwarzschild radii. We now await until such observations will be performed.
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