July 18, 2017
Keio University
A research team from Keio University, led by Shunya Takekawa (a third-year student in the Doctoral Programs at the Graduate School of Science and Technology and a JSPS Research Fellow) and Professor Tomoharu Oka of the Department of Physics, Faculty of Science and Technology, conducted detailed radio spectroscopic observations of molecular gas around Sagittarius A* (Sgr A*), the central nucleus of the Milky Way galaxy. As a result, they discovered two small molecular clouds with unusual velocities at a position about 20 light-years away from Sgr A*. These peculiar molecular clouds have enormous kinetic energy, but no celestial objects that could be their energy source are found. This suggests that these peculiar molecular clouds were formed by an isolated black hole without a close companion star plunging into a giant molecular cloud at high speed. This is an important result indicating that a large number of "rogue black holes" are flying around the central supermassive black hole.
The results of this research were published in the July 1 issue of the American astrophysics journal "The Astrophysical Journal Letters."
Please see below for the full press release.