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.
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
