A VERY CLOSE BINARY BLACK HOLE IN A GIANT ELLIPTICAL GALAXY 3C 66B AND ITS BLACK HOLE MERGER
- National Astronomical Observatory of Japan, 2-2-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
- Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602 (Japan)
- Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1193 (Japan)
Recent observational results provide possible evidence that binary black holes (BBHs) exist in the center of giant galaxies and may merge to form a supermassive black hole in the process of their evolution. We first detected a periodic flux variation on a cycle of 93 {+-} 1 days from the 3 mm monitor observations of a giant elliptical galaxy 3C 66B for which an orbital motion with a period of 1.05 {+-} 0.03 yr had been already observed. The detected signal period being shorter than the orbital period can be explained by taking into consideration the Doppler-shifted modulation due to the orbital motion of a BBH. Assuming that the BBH has a circular orbit and that the jet axis is parallel to the binary angular momentum, our observational results demonstrate the presence of a very close BBH that has a binary orbit with an orbital period of 1.05 {+-} 0.03 yr, an orbital radius of (3.9 {+-} 1.0) x 10{sup -3} pc, an orbital separation of (6.1{sup +1.0} {sub -0.9}) x 10{sup -3} pc, a larger black hole mass of (1.2{sup +0.5} {sub -0.2}) x 10{sup 9} M {sub sun}, and a smaller black hole mass of (7.0{sup +4.7} {sub -6.4}) x 10{sup 8} M {sub sun}. The BBH decay time of (5.1{sup +60.5} {sub -2.5}) x 10{sup 2} yr provides evidence for the occurrence of black hole mergers. This Letter will demonstrate the interesting possibility of black hole collisions to form a supermassive black hole in the process of evolution, one of the most spectacular natural phenomena in the universe.
- OSTI ID:
- 21452639
- Journal Information:
- Astrophysical Journal Letters, Vol. 724, Issue 2; Other Information: DOI: 10.1088/2041-8205/724/2/L166; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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