Giant HI Hole inside the 3-kpc Ring and the North Polar Spur - The Galactic Crater -

Abstract

Applying a newly developed tangent-circle method (TCM), we derive a volume density map of HI gas in the inner Galaxy as a function of galacto-centric distance $R$ and height $Z$. The HI hole around the Galactic Center (GC) is shown to have a crater-shaped wall, which coincides with the brightest ridge of the North Polar Spur and emanates from the 3-kpc expanding ring. The crater structure is explained by sweeping of the halo gas by a shock-wave from the GC. The unperturbed HI halo outside 3 kpc is shown to be in hydrostatic equilibrium, obeying the sech${}^{2}Z/h$ density law with a scale height $h\sim 450$ pc.

6 pages, 7 figures, 1 table, PASJ Letters accepted

References in corpus (3)

• Giant Gamma-ray Bubbles from Fermi-LAT: AGN Activity or Bipolar Galactic Wind?
• Nuclear Outflow of the Milky Way: Studying the Kinematics and Spatial Extent of the Northern Fermi Bubble
• The 200-pc Molecular Cylinder in the Galactic Centre

Cited by in corpus (8)

• The Star Formation Rate of the Milky Way as seen by Herschel
• A model for a dark matter core at the galactic center
• The volumetric star formation law in the Milky Way
• Interaction of the Galactic-Centre Super Bubbles with the Gaseous Disc
• Diagnostics of Gaseous Halo of the Milky Way by a Shock Wave from the Galactic Centre
• Morphological Evidence for the eROSITA Bubbles Being Giant and Distant Structures
• CO Emission Delineating the Interface between the Milky Way Nuclear Wind Cavity and the Gaseous Disk
• One-kpc Expanding Cylinder of HI-Gas around the Galactic Center