Interaction of the Galactic-Centre Super Bubbles with the Gaseous Disc

Abstract

The interaction of Galactic-Centre (GC) super bubbles (GSB) with the gaseous disc and halo of the Milky Way is investigated using radio continuum, X-ray, HI and CO line surveys. The radio North Polar Spur (NPS) constitutes the brightest eastern ridge of GSB, brightening towards the galactic plane and reaching $l=22°,b=+2°$ at the sharpest end, where it intersects the tangential direction of the 3-kpc expanding ring and crater. Examination of the spur ridges reveals that the entire GSB, including the NPS and its counter spurs, constitutes a GC-symmetrical $\Omega /$\rotatebox[origin=c]{180}{$\Omega$} shape. The thickness and gas density of the HI and CO discs are shown to increase sharply from the inside (lower longitude) to the outside of the 3-kpc crater. Formation of crater is explained by the sweeping of the upper layer of disc gas by the shock wave from the GC by the explosion $\sim 10$ My ago with the emitted energy of several $10^{55}$ ergs. Based on the discussion, a unified view on the structure and formation mechanism of GSB is presented.

Accepted for MNRAS, 12 pages, 13 figures

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Cited by in corpus (10)

• The small-scale dynamo in a multiphase supernova-driven medium
• Molecular Gas within the Milky Way's Nuclear Wind
• A magnetised Galactic halo from inner Galaxy outflows
• North Polar Spur: gaseous plume(s) from star-forming regions at $\sim$3-5 kpc from Galactic Center?
• CO Emission Delineating the Interface between the Milky Way Nuclear Wind Cavity and the Gaseous Disk
• Discovery of non-equilibrium ionization plasma associated with the North Polar Spur and Loop I
• Morphological Evidence for the eROSITA Bubbles Being Giant and Distant Structures
• One-kpc Expanding Cylinder of HI-Gas around the Galactic Center
• On the Hα faintness of the North Polar Spur
• Diffuse Hot Plasma in the Interstellar Medium and Galactic Outflows