HST imaging of the dusty filaments and nucleus swirl in NGC4696 at the centre of the Centaurus Cluster

TL;DR

This study uses high-resolution HST imaging to analyze the detailed structure and magnetic properties of dusty filaments and gas flows in the central galaxy of the Centaurus cluster, revealing their role in AGN feedback and accretion.

Contribution

It provides the first detailed imaging of magnetic, dusty, molecular filaments at the Bondi radius in a galaxy cluster core, highlighting their magnetic nature and dynamics.

Findings

Filaments are about 60pc wide and are dragged by AGN activity.

Magnetic fields are in pressure equilibrium with hot gas.

Cold gas filaments swirl within the Bondi radius, indicating magnetic influence.

Abstract

Narrow-band HST imaging has resolved the detailed internal structure of the 10 kpc diameter H alpha+[NII] emission line nebulosity in NGC4696, the central galaxy in the nearby Centaurus cluster, showing that the dusty, molecular, filaments have a width of about 60pc. Optical morphology and velocity measurements indicate that the filaments are dragged out by the bubbling action of the radio source as part of the AGN feedback cycle. Using the drag force we find that the magnetic field in the filaments is in approximate pressure equipartition with the hot gas. The filamentary nature of the cold gas continues inward, swirling around and within the Bondi accretion radius of the central black hole, revealing the magnetic nature of the gas flows in massive elliptical galaxies. HST imaging resolves the magnetic, dusty, molecular filaments at the centre of the Centaurus cluster to a swirl around and within the Bondi radius.