Bizarre "Infinity Galaxy" Could Hold the Secrets of Supermassive Black Holes

Yahoo

19-07-2025

Astronomers using data collected by the James Webb Space Telescope have discovered a spectacular cosmic object they're calling the "Infinity Galaxy."
The site of an epic head-on collision between two galaxies, it could harbor the secrets to how the heaviest black holes in the universe, the supermassive black holes found at the hearts of galaxies, are born and reach their unbelievable masses — masses extreme enough to organize trillions of stars around them.
"Everything is unusual about this galaxy. Not only does it look very strange, but it also has this supermassive black hole that's pulling a lot of material in," Pieter van Dokkum, lead author of a new study published in the Astrophysical Journal Letters, said in a statement about the work.
"As an unexpected bonus, it turns out that both galaxy nuclei also have an active supermassive black hole," van Dokkum added. "So, this system has three confirmed active black holes: two very massive ones in both of the galaxy nuclei, and the one in between them that might have formed there."
The singularity-studded object was found by searching through public data collected in the COSMOS-Web survey, which is designed to document the evolution of galaxies, with data gathered on 800,000 realms and counting.
In an image taken with the Webb, two bright spots represent the nuclei of each of the two colliding galaxies, both surrounded by their own ring of stars. This lends it the shape of an infinity symbol, hence its memorable name.
What's most striking, though, is what appears between them, revealed in follow-up observations: an enormous supermassive black hole swimming in a sea of ionized gas. It's estimated to contain a mass equivalent to a million times that of our own Sun — and it's still actively growing.
"It likely didn't just arrive there, but instead it formed there. And pretty recently," van Dokkum said. "We think we're witnessing the birth of a supermassive black hole — something that has never been seen before."
This could be some of the most compelling evidence yet of black holes forming by directly collapsing into a singularity from a huge, heavy cloud of gas.
The origins of supermassive black holes are one of the great mysteries of cosmology. They undeniably exist, forming the heart of the largest galaxies, including our own Milky Way — but how they form and gain such unbelievable heft is still hotly debated; the heaviest black holes may weigh hundreds of billions of solar masses.
The most well-known way that black holes are born is through the collapse of a very massive star that explodes in a supernova. This might spawn a black hole with several to a hundred times the mass of the Sun, maybe even a thousand. Then, give one of these stellar-mass black holes hundreds of millions to billions of years to devour matter that falls into it, or merge with other black holes, and it might reach a supermassive stature.
Astronomers, however, have observed black holes boasting millions of solar masses while existing just 400 million years after the Big Bang, which simply isn't enough time for one to reach its size by gradually accreting matter.
That points to another possibility called the "heavy seed theory," explains van Dokkum, "where a much larger black hole, maybe up to one million times the mass of our Sun, forms directly from the collapse of a large gas cloud." This would've been facilitated by the hot conditions of the early universe, allowing a gas cloud to collapse into one large object instead of forming numerous smaller stars.
"It's not clear that this direct-collapse process could work in practice," van Dokkum said.
But there's compelling reason to believe that the Infinity Galaxy is home to a black hole born through this exact process. The best clue is the central supermassive black hole's velocity, which matches up with the surrounding gas, strongly suggesting it formed right where we're seeing it. If it formed elsewhere in the cosmos and barged into the mix, the velocity would be significantly higher.
What astronomers think happened, then, is that when the constituent two galaxies collided, the gas contained in them compressed to form a "dense knot," van Dokkum said, "which then collapsed into a black hole."
"We can't say definitively that we have found a direct collapse black hole," van Dokkum concluded. "But we can say that these new data strengthen the case that we're seeing a newborn black hole, while eliminating some of the competing explanations."
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