Cold gas removal from the centre of a galaxy by a low-luminosity jet

TL;DR

This study demonstrates that low-luminosity radio jets can drive massive molecular outflows in galaxy centers, influencing galaxy evolution by removing gas and providing a new perspective on AGN feedback mechanisms.

Contribution

It provides the first spatially-resolved evidence linking low-luminosity jets to molecular outflows in galaxy centers, highlighting their role in galaxy evolution.

Findings

Detected a massive molecular outflow coinciding with a low-luminosity jet.

The outflow carries about 75% of the central gas.

Jet power is sufficient to drive the observed outflow.

Abstract

The energy emitted by active galactic nuclei (AGN) may provide a self-regulating process (AGN feedback) that shapes the evolution of galaxies. This is believed to operate along two modes: on galactic scales by clearing the interstellar medium via outflows, and on circumgalactic scales by preventing the cooling and accretion of gas onto the host galaxy. Radio jets associated with radiatively-inefficient AGN are known to contribute to the latter mode of feedback. However, such jets could also play a role on circum-nuclear and galactic scales, blurring the distinction between the two modes. We have discovered a spatially-resolved, massive molecular outflow, carrying $\sim75\%$ of the gas in the central region of the host galaxy of a radiatively-inefficient AGN. The outflow coincides with the radio jet 540 pc offset from the core, unambiguously pointing to the jet as the driver of this phenomenon. The modest luminosity of the radio source ($L\rm_{1.4 GHz}=2.1 \times 10\rm^{23}~\rm W~\rm Hz^{-1}$) confirms predictions of simulations that jets of low-luminosity radio sources carry enough power to drive such outflows. Including kpc-scale feedback from such sources -- comprising of the majority of the radio AGN population -- in cosmological simulations may assist in resolving some of their limitations.