Cosmic-ray driven outflow from the galactic center and the origin of magnetized radio filaments

Abstract

Radio, X-ray and infrared observations of the inner few hundred pc of the Galactic center have highlighted two characteristics to the ISM. The cosmic ray ionization rate derived from molecular ions such as H${}_3^{+}$, is at least two to three orders of magnitudes higher than in the Galactic disk. The other is bipolar X-ray and radio emission away from the Galactic plane. These features are consistent with a scenario in which high cosmic ray pressure drives large-scale winds away from the Galactic plane. The interaction of such a wind with stellar wind bubbles may explain the energetic nonthermal radio filaments found throughout the Galactic center. Some of the implications of this scenario is the removal of gas driven by outflowing winds, acting as a feedback to reduce the star formation rate in the central molecular zone (CMZ), and the distortion of azimuthal magnetic field lines in the CMZ to vertical direction away from the plane. The combined effects of the wind and vertical magnetic field can explain why most magnetized filaments run perpendicular to the Galactic plane. This proposed picture suggests our Milky Way nucleus has recently experienced starburst or black hole activity, as recent radio and X-ray observations indicate.

6 pages, 2 figures, MNRAS, in press

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Cited by in corpus (22)

• The 1.28 GHz MeerKAT Galactic Center Mosaic
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• High-energy particles and radiation in star-forming regions
• Probing Cosmic Ray Transport with Radio Synchrotron Harps in the Galactic Center
• The Galactic center chimneys: The base of the multiphase outflow of the Milky Way
• Statistical Properties of the Population of the Galactic Center Filaments: The Spectral Index and Equipartition Magnetic Field
• Constraining the population of isolated massive stars within the Central Molecular Zone
• The Population of the Galactic Center Filaments: Position Angle Distribution Reveal a Degree-scale Collimated Outflow from Sgr A* along the Galactic Plane
• A Supernova-driven, Magnetically-collimated Outflow as the Origin of the Galactic Center Radio Bubbles
• Populations of Magnetized Filaments in the Intracluster Medium and the Galactic Center
• Chandra large-scale mapping of the Galactic center: Probing high-energy structures around the central molecular zone
• The Central 300 pc of the Galaxy probed by infrared spectra of H3+ and CO: II. Expansion and morphology of the warm diffuse gas
• Statistical Properties of the Population of the Galactic Center Filaments II: The Spacing Between Filaments
• Galactic Centre Threads as Nuclear MHD Waves
• The population of Galactic centre filaments III: candidate radio and stellar sources
• Nonthermal filaments from the tidal destruction of clouds in the Galactic center
• G0.173-0.42: an X-ray and radio magnetized filament near the galactic center
• Supernova-remnant origin of the Galactic-Centre filaments
• A VLA Study of Newly-Discovered Southern Latitude Non-Thermal Filaments in the Galactic Center: Radio Continuum Total-intensity and Spectral Index Properties
• Feedback between Sgr A and B : AGN-Starburst Connection in the Galactic Centre
• SOFIA/HAWC+ Far-Infrared Polarimetric Large Area CMZ Exploration Survey. V. The Magnetic Field Strength and Morphology in the Sagittarius C Complex
• The SARAO MeerKAT Galactic Plane Survey filamentary source catalogue