Detection of Another Molecular Bubble in the Galactic Center

Shiho Tsujimoto, Tomoharu Oka, Shunya Takekawa, Masaya Yamada, Sekito Tokuyama, Yuhei Iwata, Justin A. Roll

Research output: Contribution to journalArticle

Abstract

The l = -1°2 region in the Galactic center has a high CO J = 3-2/J = 1-0 intensity ratio and extremely broad velocity width. This paper reports the detection of five expanding shells in the l = -1°2 region based on the Co J = 1-0, 13CO J = 1-0, CO J = 3-2, and SiO J = 8-7 line data sets obtained with the Nobeyama Radio Observatory 45 m telescope and James Clerk Maxwell Telescope. The kinetic energy and expansion time of the expanding shells are estimated to be 1048.350.8 erg and 104.75.0 yr, respectively. The origin of these expanding shells is discussed. The total kinetic energy of 1051 erg and the typical expansion time of ∼105yr correspond to multiple supernova explosions at a rate of 10-5-10-4 yr-1. This indicates that the l = -1°2 region may be a molecular bubble associated with an embedded massive star cluster, although the absence of an infrared counterpart makes this interpretation somewhat controversial. The expansion time of the shells increases as the Galactic longitude decreases, suggesting that the massive star cluster is moving from Galactic west to east with respect to the interacting molecular gas. We propose a model wherein the cluster is moving along the innermost x1 orbit and the interacting gas collides with it from the Galactic eastern side.

Original languageEnglish
Article number91
JournalAstrophysical Journal
Volume856
Issue number2
DOIs
Publication statusPublished - 2018 Apr 1

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Keywords

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

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Tsujimoto, S., Oka, T., Takekawa, S., Yamada, M., Tokuyama, S., Iwata, Y., & Roll, J. A. (2018). Detection of Another Molecular Bubble in the Galactic Center. Astrophysical Journal, 856(2), [91]. https://doi.org/10.3847/1538-4357/aab36b