Orbital Motion in the Radio Galaxy 3C 66B: Evidence for a Supermassive Black Hole Binary
Hiroshi Sudou,1*
Satoru Iguchi,2
Yasuhiro Murata,3
Yoshiaki Taniguchi1
Supermassive black hole binaries may exist in the centers of active galactic nuclei such as quasars and radio galaxies, and mergers between galaxies may result in the formation of supermassive binaries during the course of galactic evolution. Using the very-long-baseline interferometer, we imaged the radio galaxy 3C 66B at radio frequencies and found that the unresolved radio core of 3C 66B shows well-defined elliptical motions with a period of 1.05 ± 0.03 years, which provides a direct detection of a supermassive black hole binary.
1 Astronomical Institute, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
2 National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588, Japan.
3 Institute of Space and Astronautical Science, Sagamihara, Kanagawa 229-8510, Japan.
* Present address: Faculty of Engineering, Gifu University, Gifu 501-1193, Japan.
To whom correspondence should be addressed. E-mail: sudou{at}cc.gifu-u.ac.jp
