The Rate of Gas Accretion onto Black Holes Drives Jet Velocity

TL;DR

This study demonstrates a positive correlation between black hole accretion rates and jet velocities, revealing how accretion influences jet dynamics and feedback into the environment.

Contribution

It provides the first quantitative analysis linking accretion rates to jet velocities and supports the spine-sheath jet model.

Findings

Higher accretion rates correlate with faster jet knots.

Jet velocity depends on polar angle, supporting the spine-sheath model.

Accretion influences black hole feedback mechanisms.

Abstract

Accreting black holes are observed to launch relativistic, collimated jets of matter and radiation. In some sources, discrete ejections have been detected with highly relativistic velocities. These particular sources typically have very high mass accretion rates, while sources lower knot velocities are predominantly associated with black holes with relatively low mass accretion rates. We quantify this behavior by examining knot velocity with respect to X-ray luminosity, a proxy for mass accretion rate onto the black hole. We find a positive correlation between the mass-scaled X-ray luminosity and jet knot velocity. In addition, we find evidence that the jet velocity is also a function of polar angle, supporting the "spine-sheath" model of jet production. Our results reveal a fundamental aspect of how accretion shapes mechanical feedback from black holes into their host environments.