Supermassive black holes 'cook' their own meals with hot gas, finds study of enormous galaxy clusters

The most massive black holes in the Universe can generate their own meals, according to a study of enormous galaxy clusters.

Astronomers made the discovery by looking the centres of galaxy clusters, which are huge groupings of galaxies gravitationally held together.

At the centre of galaxy clusters lie the most massive galaxies in the Universe, which host supermassive black holes billions of times the mass of our Sun.

Astronomers know that jets of material shoot outwards from supermassive black holes when they feed on cosmic material.

But this new study shows evidence that these outbursts could be providing further source of food for the black holes.

Making the discovery

This international study, led by the University of Santiago de Chile, was carried out using NASA’s Chandra X-ray Observatory and ESO's Very Large Telescope (VLT) to observe seven clusters of galaxies.

The images here show two of the galaxy clusters in the study, the Perseus Cluster and the Centaurus Cluster.

Chandra x-ray data in blue shows filaments of hot gas, while optical data from the VLT shows cooler filaments in red.

The astronomers found that outbursts from the black holes are causing hot gas to cool and form narrow filaments of warm gas.

Some of this warm gas then gets sucked back into the black holes, causing another jet outburst.

This outburst causes more gas to cool, feeding the black holes and continuing the cycle.

The study also found that, in regions where the hot gas is brighter, the warm gas is also brighter: further evidence that correlates with a previous theory on how this process could play out.

Explaining the images

The images seen here are 'composite' images, meaning they were produced using more than one set of data.

They each show a galaxy cluster containing a central supermassive black hole surrounded by filaments of gas.

In each image, the central white dots are black holes. Purple patches represent hot x-ray gas, while pink veins are filaments of warm gas.

Jets from the black holes are hitting this hot x-ray gas, which then cools to become 'warm', and some of this warm gas flows back into the black hole.

This work was led by Valeria Olivares from the University of Santiago de Chile, was published on 27 January 2025 in Nature Astronomy and is available online.