1993 Fiscal Year Final Research Report Summary
Mass supply to active galactic nuclei by self-gravitational instability of gas
| Project/Area Number |
04640261
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Astronomy
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| Research Institution | Hokkaido University |
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Principal Investigator |
HABE Asao Hokkaido University, Dept.Science ; Lecturer, 理学部, 講師 (90180926)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Active Galaxies / Mass Supply to AGN / Self-gravitational Instability / Massive Black Hole / Star Burst Galaxies / Bar Structure in a Galaxy / Numerical Hydrodynamics / the inner Lindblad resonance |
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| Research Abstract |
It is proposed that huge energy released in active galactic nuclei comes from gravitational energy of gas accreting into massive black hole. However, since gas distributes mainly outside a galactic center, angular momentum transfer from gas is needed to supply gas from the outside galactic center to the galactic center. Similar mass supply mechanism is needed in nuclear starburst galaxies.
In this research, I study the effects of weak bar potential and self-gravity of fas on the gas motion in galactic central region to show that angular momentum transfer by these effects is very effect.
In the first year, I study self-gravitational gas motion in a fixed galaxy potential with weak bar component by numerical hydrodynamics. I got the numerical results that, after gas is accumulated into the radius of the inner Lindblad resonance, gas clumps are formed by self-gravitational instablility and gas supply into the galactic center due to the energy loss and angular momentum loss by collisions between these clumps.
In the second year, I extend the study to the two-component model of self-gravitational gas and stars, since self-gravity of gas can not be neglected for stellar system. Initially I assumed self-consistent, weak bar potential of a stellar system and study gas and stellar motion. Our numerical results show that, after gas is accumulated by the inner Lindblad resonance, central mass concentration changes the stellar structure and weak barred structure become weaker by the gas and stellar interaction. These results indicate that, when sufficient gas concentrates into the galactic center, it is gard to detect bar structure.
I have already published some parts of this study as scientific papers and I prepare to submit a paper for the other part.
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