How do supermassive black holes 'feed' themselves?

By UdeMnouvelles Jul 14th, 2026

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In 5 seconds Canadian astronomers led by an Université de Montréal professor Julie Hlavacek-Larrondo employ the James Webb Space Telescope to reveal that black holes may be the ultimate "cosmic recyclers."

An image of elliptical galaxy NGC4696 located at the center of the Centaurus Cluster taken by the Hubble Space Telescope. This image shows dusty filaments surrounding the center of the galaxy.
Photo : NASA, ESA/Hubble, A. Fabian

Using the James Webb Space Telescope (JWST), astronomers led by Université de Montréal professor Julie Hlavacek-Larrondo have captured one of the clearest views yet of how a supermassive black hole sustains itself, helping elucidate a longstanding mystery of astrophysics. The results were published in The Astrophysical Journal Letters.

Self-regulating black holes

Nearly every large galaxy in the Universe has a supermassive black hole (SMBH) at its centre that's millions or even billions of times more massive than the Sun. When these black holes are actively pulling in surrounding material, they switch on like cosmic engines, blasting powerful jets of energy outward that can sculpt the entire galaxy around them, slowing down the birth of new stars and influencing how the galaxy grows over time. Astronomers call these types of black holes active galactic nuclei (AGN).

Despite extensive research, a puzzle has stumped scientists for years. If an AGN’s jets heat up the surrounding gas, it should, in principle, shut off the black hole's 'food supply,' the energy that feeds it. So how does it keep growing?

The leading hypothesis is that the gas eventually cools back down, condenses into long thin streamers called filaments, and falls back toward the galaxy's centre. The SMBH feeds the process that feeds the SMBH; it is self-regulating.

Despite decades of searching, directly observing how these filaments actually connect to the black hole has remained very difficult. That connection, a sort of missing link, is exactly what the new UdeM-led study reveals.

A swirl becomes a spinning disk

The researchers pointed JWST at galaxy NGC 4696, the central galaxy of the Centaurus Cluster, a dense group of galaxies located about 145 million light-years from Earth and one of the best laboratories for studying AGN mechanisms.

Previous images from the Hubble Space Telescope had shown a curious S-shaped swirl of gas near the galaxy's central black hole, but Hubble could only capture a snapshot of where the gas sat, not how it was moving.

With nearly eight hours of observing time using JWST's NIRSpec instrument, the research team produced detailed maps of the gas's motion deep inside the black hole's sphere of influence, at a resolution sharp enough to pick out features roughly 30 light-years wide — a tiny slice of a galaxy that's hundreds of thousands of light-years wide.

A close-up of the center of galaxy NGC4696 around its supermassive black hole. The background greyscale imaging comes from the Hubble Space Telescope. The overlaid coloured map shows the distribution of gas falling into the black hole as traced by the Paschen α line using the James Webb Space Telescope NIRSpec instrument. An S-shaped swirl can be seen in the gas.
Photo : NASA/ESA/CSA/STScI/J. Hlavacek-Larrondo, et al. 2026

These maps showed that the S-shaped swirl is actually a spinning disk of gas wrapped around the SMBH, nearly 800 light-years across, with material whipping around at up to 600 kilometres per second. And critically, that disk appears physically connected to one of the large infalling filaments stretching outward into the galaxy. The observations showed gas flowing along the filament, pouring into the disk, and from the disk falling onto the SMBH.

"What JWST is revealing is that black holes may be the ultimate cosmic recyclers,” said Hlavacek-Larrondo, the study's lead author. “They release enormous amounts of energy that heat their surroundings, yet that same gas can later cool into thin filaments that fall back inward and feed the black hole again. We are finally seeing this self-sustaining cycle in action."

Julie Hlavacek-Larrondo, a professor at Université de Montréal, is the lead author of this study.
Photo : Sylvie Li, Shoot Studio

Closing the loop

The study helps astronomers paint a better picture of the full feeding cycle of a SMBH.

Jets from the black hole pump energy into the galaxy's surrounding gas. That gas eventually cools, becomes unstable, and collapses into long filaments, some only a few hundred light-years wide but stretching thousands of light-years long.

Magnetic forces slow the gas’s rotation as it falls, steering it inward. It accumulates into a spinning disk around the black hole. The disk feeds the black hole. The black hole fires its jets. And the cycle begins again.

These findings have sparked a broad new observational effort for galaxy NGC 4696 and similar systems, with approved JWST programs and complementary campaigns using facilities around the globe. Altogether, the scientists say the new data will help improve their understanding of how black holes feed themselves and regulate galaxy growth across the Universe.

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