2018/03/29
Keio University
A research team led by Shiho Tsujimoto (a second-year master's student at the Graduate School of Science and Technology) and Professor Tomoharu Oka of the Department of Physics, Faculty of Science and Technology, Keio University, has discovered a peculiar molecular cloud with an unusually large velocity width in the center of the Milky Way Galaxy, approximately 30,000 light-years from the solar system. The peculiar molecular cloud is about 50 light-years in size and contains at least five expanding shell-like structures within it. This is thought to be evidence of a massive explosion that occurred here about 100,000 years ago. The energy of the explosion is equivalent to about 10 supernova explosions, and it is presumed that a supermassive star cluster of several hundred thousand solar masses is hidden here. Within such massive star clusters in the galactic center, it is believed that "intermediate-mass" black holes are formed through repeated mergers of stars and black holes. The supermassive star cluster found this time is considered a candidate for a "cradle" of such intermediate-mass black holes, and this marks the second discovery of its kind in the Milky Way Galaxy, following the star cluster discovered by the same team in 2012.
The results of this research were published in the American scientific journal "The Astrophysical Journal" on March 28.
Please see below for the full press release.