1. Observational Evidence of a Centi-parsec Supermassive Black Hole Binary Existing in the Nearby Galaxy M81.
- Author
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Jiang, Wu, Shen, Zhiqiang, Martí-Vidal, Ivan, Yan, Zhen, Huang, Lei, Gold, Roman, Li, Ya-Ping, Xie, Fuguo, and Kawaguchi, Noriyuki
- Subjects
SUPERMASSIVE black holes ,BINARY black holes ,X-ray binaries ,ACTIVE galactic nuclei ,VERY long baseline interferometry ,BLACK holes ,ACCRETION (Astrophysics) - Abstract
Studying a centi-parsec supermassive black hole binary (SMBHB) would allow us to explore a new parameter space in active galactic nuclei, and these objects are also potential sources of gravitational waves. We report evidence that an SMBHB with an orbital period of ∼30 yr may be resident in the nearby galactic nucleus M81. This orbital period and the known mass of M81 imply an orbital separation of ∼0.02 pc. The jet emanating from the primary black hole showed a short period of jet wobbling at ∼16.7 yr, superposing a long-term precession at a timescale of several hundred years. Periodic radio and X-ray outbursts were also found two times per orbital period, which could be explained by a double-peaked mass accretion rate variation per binary orbit. If confirmed, M81 would be one of the closest SMBHB candidates, providing a rare opportunity to study the final parsec problem. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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