EFFICIENT MERGER OF BINARY SUPERMASSIVE BLACK HOLES IN NON- AXISYMMETRIC GALAXIES

Binary supermassive black holes form naturally in galaxy mergers, but their long-term evolution is uncertain. In spherical galaxies, N-body simulations show that binary evolution stalls at separations much too large for significant emission of gravitational waves (the “final pars ec problem”). Here, we follow the long-term evolution of a massive binary in more realistic, triaxial and rota ting galaxy models. We find that the binary does not stall. The binary hardening rates that we observe are suffici ent to allow complete coalescence of binary SBHs in 10 Gyr or less, even in the absence of collisional loss-con e refilling or gas-dynamical torques, thus providing a potential solution to the final parsec problem. Subject headings:

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