A team of researchers has identified an isolated "Tadpole" molecular cloud near Sagittarius A* at the galactic nucleus of the Milky Way. The discovery was made by Miyuki Kaneko, a 2nd Year Master’s student in the Graduate School of Science and Technology at Keio University, and Professor Tomoharu Oka who works in the Department of Physics at the Faculty of Science and Technology at the same school. Researchers from the National Astronomical Observatory of Japan and Kanagawa University also contributed to the study. The molecular cloud they discovered is shaped like an arc in space and its radial velocity clearly varies monotonically along this arc. The researchers were able to replicate this spatial-velocity behavior by using a Keplerian orbit modeled around a point-like massive object (point mass) estimated to have a mass 100,000 times that of the Sun. Examinations of other wavelengths did not reveal any luminous counterpart, meaning that this point mass is not a high-density stellar cluster. At this point in time, the most likely explanation is that the point mass is an intermediate-mass black hole. This object may be the most convincing candidate for an intermediate-mass black hole among any that have been discovered from molecular gas kinematics.
This paper was published in the January 10 issue of The Astrophysical Journal, an American academic journal that specializes in astrophysics research.