Indication of Another Intermediate-mass Black Hole in the Galactic Center

Shunya Takekawa, Tomoharu Oka, Yuhei Iwata, Shiho Tsujimoto, Mariko Nomura

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)


We report the discovery of molecular gas streams orbiting around an invisible massive object in the central region of our Galaxy, based on the high-resolution molecular line observations with the Atacama Large Millimeter/submillimeter Array. The morphology and kinematics of these streams can be reproduced well through two Keplerian orbits around a single point mass of (3.2 ± 0.6) ×10 4 M o . We also found ionized gas toward the inner part of the orbiting gas, indicating dissociative shock and/or photoionization. Our results provide new circumstantial evidences for a wandering intermediate-mass black hole in the Galactic center, suggesting also that high-velocity compact clouds can be probes of quiescent black holes that abound in our Galaxy.

Original languageEnglish
Article numberL1
JournalAstrophysical Journal Letters
Issue number1
Publication statusPublished - 2019 Jan 20


  • Galaxy: center
  • ISM: clouds
  • ISM: molecules
  • submillimeter: ISM

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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