銀河中心の巨大ブラックホールのまわりのガス円盤の進化

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When a central massive black hole exists in a galaxy, the additional inner Lindblad resonance (ILR) exists inside the usual ILR.We call this resonance as the nuclear Lindblad resonance. We study the gas dynamics in a weakly barred potential with a massive black hole by using 2D numerical simulations in order to investigate the effect of the nuclear Lindblad resonance caused by a central massive black hole in a galaxy, and to clarify a role of the nuclear Lindblad resonance in triggering the gas fueling to nuclear starburst regions or AGNs.Our numerical results show that strong trailing spiral shocks are formed in the nuclear Lindblad resonance region and the gas in the shock region is rapidly fueled into central region and make a nuclear gas ring. As a results, a large amount of the gas concentrates in the nuclear region beyond the ILR radius in a dynamical time scale and a gas ring is formed. During the gas accumulation process, the strong shocks are created. These strong shocks can trigger burst star formations.The size occupied by gas before accumulation depends on the mass of black hole or pattern speed of bar. We study the linear stability of the finally formed gas ring and find that the the gas ring is easy to be gravitational unstable. In this case, we can expect fragmentation of the gas ring and further concentration of gas into the black hole.