The Astrophysical Journal Letters (Jan 2024)

X-Rays from a Central “Exhaust Vent” of the Galactic Center Chimney

  • Scott C. Mackey,
  • Mark R. Morris,
  • Gabriele Ponti,
  • Konstantina Anastasopoulou,
  • Samaresh Mondal

DOI
https://doi.org/10.3847/2041-8213/ad3248
Journal volume & issue
Vol. 966, no. 2
p. L32

Abstract

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Using deep archival observations from the Chandra X-ray Observatory, we present an analysis of linear X-ray-emitting features located within the southern portion of the Galactic center chimney and oriented orthogonal to the Galactic plane, centered at coordinates l = 0.°08, b = −1.°42. The surface brightness and hardness ratio patterns are suggestive of a cylindrical morphology, which may have been produced by a plasma outflow channel extending from the Galactic center. Our fits of the feature’s spectra favor a complex two-component model consisting of thermal and recombining plasma components, possibly a sign of shock compression or heating of the interstellar medium by outflowing material. Assuming a recombining plasma scenario, we further estimate the cooling timescale of this plasma to be on the order of a few hundred to thousands of years, leading us to speculate that a sequence of accretion events onto the Galactic black hole may be a plausible quasi-continuous energy source to sustain the observed morphology.

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