The universe’s most massive black holes fuel themselves by cooling gas around them, astronomers have found. Using data from NASA’s Chandra X-ray Observatory and the Very Large Telescope (VLT) in Chile, researchers have demonstrated how black hole outbursts trigger a self-sustaining feeding process.
The study, published in Nature Astronomy and led by Valeria Olivares from the University of Santiago de Chile, examined seven galaxy clusters. At the centres of these clusters lie enormous black holes, weighing millions to billions of times the Sun’s mass. These black holes feed on surrounding gas, releasing powerful jets that cool the gas and form filaments.
The research found that outbursts from black holes cool hot gas, forming narrow filaments of warm gas visible as glowing threads. Turbulence in the gas plays a key role in this cooling process. Some of the warm gas flows back into the black hole, fuelling more outbursts and continuing the cycle.
One key discovery was that the brightness of hot gas is linked to the brightness of warm gas in the clusters’ centres. When the hot gas shines brighter, the warm gas glows more intensely, confirming how black holes feed on surrounding gas.
Two galaxy clusters – Perseus and Centaurus – offer a striking visual of this phenomenon.
Perseus Cluster: The hot gas appears bluish-purple with solid pink filaments, while surrounding galaxies shine brightly.
Centaurus Cluster: The gas has a softer, diffused look, with filaments showing delicate, feathery textures.
Both clusters display central black holes surrounded by glowing filaments of gas, a visual representation of the self-sustaining feeding mechanism.
The study noted similarities between the gas filaments in galaxy clusters and the tails of “jellyfish galaxies,” where gas is stripped as galaxies move through their surroundings. This unexpected connection suggests a shared process across different cosmic phenomena.
The research brought together experts from Chile, the US, Australia, Canada, and Italy, leveraging advanced tools like the VLT’s MUSE (Multi Unit Spectroscopic Explorer) instrument to create 3D views of the universe. NASA’s Chandra programme, managed from Alabama, provided the X-ray data critical to this discovery.
