X-rays from a Central "Exhaust Vent" of the Galactic Center Chimney

TL;DR

This study analyzes X-ray features in the Galactic center chimney, suggesting a plasma outflow from the center with complex thermal components and a potential link to accretion events onto the Galactic Black Hole.

Contribution

It provides the first detailed spectral analysis of linear X-ray features in the Galactic center chimney, proposing a plasma outflow model with complex thermal components.

Findings

Evidence of a plasma outflow channel from the Galactic center.

Spectral fits favor a two-component thermal and recombining plasma model.

Estimated plasma cooling timescale of a few hundred to thousands of years.

Abstract

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 deg, b = -1.42 deg. 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.