2019ApJ...875...32N

We report the discovery of a 1° scale X-ray plume in the northern Galactic Center (GC) region observed with Suzaku. The plume is located at (l, b) ∼ (0.°2, 0.°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 are reproduced by a thin thermal plasma model with kT ∼ 0.7 keV and solar metallicity. There is no signature of non-equilibrium ionization. The unabsorbed surface brightness is 3 x 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 ∼100 pc, density of 0.1 cm^–3, thermal pressure of 1 x 10^–10 erg cm^–3, mass of 600 M_☉, and thermal energy of 7 x 10⁵⁰ 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.