X-ray Observation of a Magnetized Hot Gas Outflow in the Galactic Center Region

Abstract

We report the discovery of a $1^{\circ }$ scale X-ray plume in the northern Galactic Center (GC) region observed with Suzaku. The plume is located at ($l$, $b$) $\sim$ ($0\mbox{$.\!\!^\circ$}2$, $0\mbox{$.\!\!^\circ$}6$), east of the radio lobe reported by previous studies. No significant X-ray excesses are found inside or to the west of the radio lobe. The spectrum of the plume exhibits strong emission lines from highly ionized Mg, Si, and S that is reproduced by a thin thermal plasma model with $kT\sim 0.7$ keV and solar metallicity. There is no signature of non-equilibrium ionization. The unabsorbed surface brightness is $3\times 10^{-14}$ erg cm${}^{-2}$ s${}^{-1}$ arcmin${}^{-2}$ in the 1.5-3.0 keV band. Strong interstellar absorption in the soft X-ray band indicates that the plume is not a foreground source but is at the GC distance, giving a physical size of $\sim$100 pc, a density of 0.1 cm${}^{-3}$, thermal pressure of $1\times 10^{-10}$ erg cm${}^{-3}$, mass of 600 $M_{\odot }$ and thermal energy of $7\times 10^{50}$ erg. From the apparent association with a polarized radio emission, we propose that the X-ray plume is a magnetized hot gas outflow from the GC.

9 pages, accepted for publication in ApJ

References in corpus (5)

• Giant Gamma-ray Bubbles from Fermi-LAT: AGN Activity or Bipolar Galactic Wind?
• The Spectrum and Morphology of the Fermi Bubbles
• Spatial distribution of interstellar gas in the innermost 3 kpc of our Galaxy
• The Chandra COSMOS legacy survey: Energy Spectrum of the Cosmic X-ray Background and constraints on undetected populations
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Cited by in corpus (14)

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• The Galactic center chimneys: The base of the multiphase outflow of the Milky Way
• Cosmic-ray driven outflow from the galactic center and the origin of magnetized radio filaments
• A Supernova-driven, Magnetically-collimated Outflow as the Origin of the Galactic Center Radio Bubbles
• Chandra large-scale mapping of the Galactic center: Probing high-energy structures around the central molecular zone
• Galactic Centre Threads as Nuclear MHD Waves
• A mean density of $112M_{\odot }\mathrm{p}{\mathrm{c}}^{-3}$ for Central Molecular Zone clumps -- Evidences for shear-enabled pressure equilibrium in the Galactic Center
• Supernova-remnant origin of the Galactic-Centre filaments
• Cold molecular gas in the hot nuclear wind of the Milky Way
• Sources and Radiations of the Fermi Bubbles
• Evidence for powerful winds and the associated reverse shock as the origin of the Fermi bubbles
• High Energy Emission from the Galactic Center