On the Hα faintness of the North Polar Spur

Abstract

The ratio of H$\alpha$ intensity to 1.4 GHz radio continuum intensity in the North Polar Spur (NPS) is measured to be $\lesssim 50$, two orders of magnitude smaller than the values of $\sim 10^4$ observed in the typical shell-type old supernova remnants, Cygnus Loop and S147. The extremely low H$\alpha$-to-radio intensity ratio favours the Galactic-Centre explosion model for NPS, which postulates a giant shock wave at a distance of several kilo parsecs in the hot and low-density Galactic halo with low hydrogen recombination rate, over the local supernova(e) remnant model.

arXiv commentAccepted for MNRAS, 8 pages, 8 figures

References in corpus (29)

• A Hipparcos census of the nearby OB associations
• A Quantitative Comparison of SMC, LMC, and Milky Way UV to NIR Extinction Curves
• The Wisconsin H-Alpha Mapper Northern Sky Survey
• The Large-scale Bipolar Wind in the Galactic Center
• Detection of large-scale X-ray bubbles in the Milky Way halo
• Very Extended X-ray and H-alpha Emission in M82: Implications for the Superwind Phenomenon
• Updated Gaia-2MASS 3D maps of Galactic interstellar dust
• Dark matter in the Milky Way, II. the HI gas distribution as a tracer of the gravitational potential
• The radio emission from the Galaxy at 22 MHz
• A New Model For The Loop-I (The North Polar Spur) Region
• Suzaku observations of the diffuse x-ray emission across the fermi bubbles' edges
• Tightly Correlated X-ray/H$\alpha$ Emitting Filaments in the Superbubble and Large-Scale Superwind of NGC 3079
• Spatially resolved optical IFU spectroscopy of the inner superwind of NGC 253
• X-ray and Gamma-ray Observations of the Fermi Bubbles and NPS/Loop I Structures
• Radio spectral properties and the magnetic field of the SNR S147
• Radio emission from the Cygnus Loop and its spectral characteristics
• The North Polar Spur and Aquila Rift
• Mapping the three-dimensional dust extinction toward the supernova remnant S147 - the S147 dust cloud
• Kompaneets Model Fitting of the Orion-Eridanus Superbubble II: Thinking Outside of Barnard's Loop
• Galactic-Center Hyper-Shell Model for the North Polar Spurs
• The Plasma Structure of the Southwestern Region of the Cygnus Loop with the XMM-Newton Observatory
• Interaction of the Galactic-Centre Super Bubbles with the Gaseous Disc
• Origin of Galactic Spurs: New Insight from Radio/X-ray All-sky Maps
• A Distance Estimate to the Cygnus Loop Based on the Distances to Two Stars Located Within the Remnant
• Bipolar hypershell models of the extended hot interstellar medium in spiral galaxies
• Interaction of the Loop I Supershell with the Local Hot Bubble
• Discovery of non-equilibrium ionization plasma associated with the North Polar Spur and Loop I
• Three-Dimensional Aquila Rift: Magnetized HI Arch Anchored by Molecular Complex
• One-kpc Expanding Cylinder of HI-Gas around the Galactic Center

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