A high-velocity molecular cloud near the center of the Galaxy

Oka Tomoharu, Glenn J. White, Tetsuo Hasegawa, Fumio Sato, Masato Tsuboi, Atsushi Miyazaki

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


We report the detection of a peculiar molecular cloud, CO 0.02-0.02, lying about 5′ Galactic east from the center of the Galaxy. 12CO images taken with Nobeyama Radio Observatory (NRO) 45 m telescope showed that it is relatively compact (∼3 × 4 pc2) as well as having a very large velocity width (ΔV ≥ 100 km s-1). The cloud has a virial mass about 1 order of magnitude larger than the LTE mass, 9 × 104 M, indicating the cloud is apparently gravitationally unbound. New observations with the James Clerk Maxwell Telescope 15 m and the NRO 45 m telescopes show that CO 0.02-0.02 is very bright in the CO (J = 3-2) and in the HCN and HCO+ (J = 1-0) lines. It appears that the environment may have an unusually high density and temperature, which may be related to the very broad CO line width. We propose that CO 0.02 -0.02 may have been accelerated, heated, and compressed in a series of supernovae shocks that have occurred within the last (3-5) × 104 yr.

Original languageEnglish
Pages (from-to)249-255
Number of pages7
JournalAstrophysical Journal
Issue number1 PART 1
Publication statusPublished - 1999 Apr 10
Externally publishedYes


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

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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