An international team of astronomers used the state-of-the-art capability of VERA, a Japanese network of radio telescopes operated by NAOJ, to uncover valuable clues about how rapidly growing “young” supermassive black holes form, grow, and possibly evolve into more powerful quasars.
Observations by the East Asian VLBI Network have revealed periodic motions in the jet emanating from the center of the elliptical galaxy M87−specifically, a precessional motion with a cycle of approximately 11 years and a lateral wobble with a cycle of about 0.9 years. An international research team from Kogakuin University, the National Astronomical Observatory of Japan (NAOJ), Bunkyo University, the Korea Astronomy and Space Science Institute (KASI), Central China Normal University, Nagoya City University, and Kyung Hee University hypothesized that these periodicities could be caused by the orbital motion of a second black hole revolving around the supermassive black hole at the center of M87. They theoretically derived the possible mass range of this hypothetical secondary black hole. Recently, the NANOGrav collaboration suggested that gravitational waves emitted by supermassive black hole binaries may have been detected as a “gravitational wave background” permeating the universe. Motivated by this, the research team focused on M87 as a promising candidate to explore this phenomenon. Their findings offer important guidance for future observational strategies aimed at directly testing the existence of supermassive black hole binaries.
We have signed a memorandum of understanding (MOU) for an international VLBI network that will combine approximately 20 radio telescopes in the East Asian region in Japan, South Korea, and China to achieve resolution equivalent to a giant radio telescope with a maximum diameter of 5,500 km.