The 200-pc Molecular Cylinder in the Galactic Centre

Abstract

Analyzing the 3D structure of the molecular gas distribution in the central 200 pc region of the Galaxy, we show that the expanding molecular ring (EMR, also known as the parallelogram) and the central molecular zone (CMZ) exhibit quite different distributions and kinematics. The EMR composes a bipolar vertical cylinder with the total length as long as $\sim 170$ pc and shows large non-circular velocities. On the contrary, the CMZ is distributed in a nearly rigid-body rotating ring and arms tightly concentrated near the galactic plane with full thickness less than $\sim 30$ pc. Furthermore, the mass and density ratios of the EMR to CMZ are as small as $\sim 0.13$ and $0.04$, respectively. We discuss the origins of the EMR and CMZ based on the bar and explosion models. We suggest that the EMR's large vertical extent can be explained by a cylindrical shock wave model driven by an explosive activity in the Galactic Centre.

arXiv commentMNRAS to appear, 9 pages, 13 figures, 1 table

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Cited by in corpus (14)

• The Galactic Centre Chimney
• Distributed star formation throughout the Galactic Center cloud Sgr B2
• The Galactic center chimneys: The base of the multiphase outflow of the Milky Way
• Three-Dimensional Structure of the Central Molecular Zone
• Evolution of Molecular Clouds in the Superwind Galaxy NGC 1808 Probed by ALMA Observations
• Asymmetric eROSITA bubbles as the evidence of a circumgalactic medium wind
• The Central 300 pc of the Galaxy probed by infrared spectra of H3+ and CO: II. Expansion and morphology of the warm diffuse gas
• Towards a three-dimensional distribution of the molecular clouds in the Galactic Centre
• Giant HI Hole inside the 3-kpc Ring and the North Polar Spur - The Galactic Crater -
• Star Formation in Extreme Environments: A 200 pc High Velocity Gas Stream in the Galactic Centre
• The Interstellar Medium toward the Galactic Center Source 2MASS J17470898-2829561
• The Central 300 pc of the Galaxy Probed by Infrared Spectra of H${}_3^{+}$ and CO: III. Locations of Sgr B2 and Star $\iota$
• Feedback between Sgr A and B : AGN-Starburst Connection in the Galactic Centre
• One-kpc Expanding Cylinder of HI-Gas around the Galactic Center