A Three Parsec-Scale Jet-Driven Outflow from Sgr A*

TL;DR

This paper presents high-resolution radio images revealing a faint, linear, jet-like outflow from Sgr A* that interacts with surrounding gas, influencing the Galactic center's environment and X-ray emission.

Contribution

It reports the discovery of a parsec-scale jet from Sgr A* and characterizes its properties and interactions with nearby gas, a novel observation of jet activity at the Galactic center.

Findings

Detection of a linear jet structure centered on Sgr A*

Interaction of the jet with surrounding ionized and molecular gas

Estimated jet kinetic luminosity of ~1.2x10^{41} erg/s

Abstract

The compact radio source Sgr A* is coincident with a 4 million solar mass black hole at the dynamical center of the Galaxy and is surrounded by dense orbiting ionized and molecular gas. We present high resolution radio continuum images of the central 3' and report a faint continuous linear structure centered on Sgr A* with a PA~60 degrees. The extension of this feature appears to be terminated symmetrically by two linearly polarized structures at 8.4 GHz, ~75" from Sgr A*. A number of weak blobs of radio emission with X-ray counterparts are detected along the axis of the linear structure. The linear structure is best characterized by a mildly relativistic jet from Sgr A* with an outflow rate 10^-6 solar mass per year. The near and far-sides of the jet are interacting with orbiting ionized and molecular gas over the last 1-3 hundred years and are responsible for a 2" hole, the "minicavity", characterized by disturbed kinematics, enhanced FeII/III line emission, and diffuse X-ray gas. The estimated kinetic luminosity of the outflow is ~1.2x10^{41} erg/s, so the interaction with the bar may be responsible for the Galactic center X-ray flash inferred to be responsible for much of the fluorescent Fe Kalpha line emission from the inner 100pc of the Galaxy.