17.07.2025
NASA’s Webb Finds Possible ‘Direct Collapse’ Black Hole
Editor’s Note: This post highlights a combination of peer-reviewed results and data from Webb science in progress, which has not yet been through the peer-review process.
As data from NASA’s James Webb Space Telescope becomes public, researchers hunt its archives for unnoticed cosmic oddities. While examining images from the COSMOS-Websurvey, two researchers, Pieter van Dokkum of Yale University and Gabriel Brammer of the University of Copenhagen, discovered an unusual object that they nicknamed the Infinity Galaxy.
It displays a highly unusual shape of two very compact, red nuclei, each surrounded by a ring, giving it the shape of the infinity symbol. The team believes it was formed by the head-on collision of two disk galaxies. Follow-up observations showed that the Infinity Galaxy hosts an active, supermassive black hole. What is highly unusual is that the black hole is in between the two nuclei, within a vast expanse of gas. The team proposes that the black hole formed there via the direct collapse of a gas cloud – a process that may explain some of the incredibly massive black holes Webb has found in the early universe.
Here Pieter van Dokkum, lead author of a peer-reviewed paper describing their initial discovery and principal investigator of follow-up Webb observations, explains why this object could be the best evidence yet for a novel way of forming black holes.
“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. The biggest surprise of all was that the black hole was not located inside either of the two nuclei but in the middle. We asked ourselves: How can we make sense of this?
“Finding a black hole that’s not in the nucleus of a massive galaxy is in itself unusual, but what’s even more unusual is the story of how it may have gotten there. It likely didn’t just arrive there, but instead it formed there. And pretty recently. In other words, we think we’re witnessing the birth of a supermassive black hole – something that has never been seen before.
“How supermassive black holes formed is a long-standing question. There are two main theories, called ‘light seeds’ and ‘heavy seeds.’ In the light seed theory, you start with small black holes formed when a star’s core collapses and the star explodes as a supernova. That might result in a black hole weighing up to about 1,000 Suns. You form a lot of them in a small space and they merge over time to become a much more massive black hole. The problem is, that merger process takes time, and Webb has found incredibly massive black holes at incredibly early times in the universe – possibly even too early for this process to explain them.
“The second possibility is the heavy seed theory, 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. You immediately form a giant black hole, so it’s much quicker. However, the problem with forming a black hole out of a gas cloud is that gas clouds like to form stars as they collapse rather than a black hole, so you have to find some way of preventing that. It’s not clear that this direct-collapse process could work in practice.
“By looking at the data from the Infinity Galaxy, we think we’ve pieced together a story of how this could have happened here. Two disk galaxies collide, forming the ring structures of stars that we see. During the collision, the gas within these two galaxies shocks and compresses. This compression might just be enough to form a dense knot, which then collapsed into a black hole.
“There is quite a bit of circumstantial evidence for this. We observe a large swath of ionized gas, specifically hydrogen that has been stripped of its electrons, that’s right in the middle between the two nuclei, surrounding the supermassive black hole. We also know that the black hole is actively growing – we see evidence of that in X-rays from NASA’s Chandra X-ray Observatory and radio from the Very Large Array. Nevertheless, the question is, did it form there?
“There are two other possibilities that come to mind. First, it could be a runaway black hole that got ejected from a galaxy and just happens to be passing through. Second, it could be a black hole at the center of a third galaxy in the same location on the sky. If it were in a third galaxy, we would expect to see the surrounding galaxy unless it were a faint dwarf galaxy. However, dwarf galaxies don’t tend to host giant black holes.
“If the black hole were a runaway, or if it were in an unrelated galaxy, we would expect it to have a very different velocity from the gas in the Infinity Galaxy. We realized that this would be our test – measure the velocity of the gas and the velocity of the black hole, and compare them. If the velocities are close, within maybe 30 miles per second (50 kilometers per second), then it becomes hard to argue that the black hole is not formed out of that gas.
“We applied for and received director’s discretionary time to follow up on this target with Webb, and our preliminary results are exciting. First, the presence of an extended distribution of ionized gas in between the two nuclei is confirmed. Second, the black hole is beautifully in the middle of the velocity distribution of this surrounding gas – as expected if it formed there. This is the key result that we were after!
“Third, as an unexpected bonus, it turns out that both galaxy nuclei also have an active supermassive black hole. 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.
“We can’t say definitively that we have found a direct collapse black hole. 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. We will continue to pore through the data and investigate these possibilities.”
Quelle: NASA
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Update: 18.07.2025
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JWST finds unusual black hole in the center of the Infinity Galaxy: 'How can we make sense of this?'
"The biggest surprise of all was that the black hole was not located inside either of the two nuclei but in the middle. We asked ourselves: How can we make sense of this?"
An image of the Infinity Galaxy as seen by the James Webb Space Telescope (Image credit: NASA, ESA, CSA, STScI, P. van Dokkum (Yale University).)
Using the James Webb Space Telescope (JWST), astronomers have discovered an oddball galaxy, dubbed the Infinity Galaxy, that could be host to a "direct collapse black hole." That is, a black hole originally created directly from a vast cloud of collapsing gas and dust rather than a dying star.
The Infinity Galaxy gets its name from the fact that its shape resembles an infinity symbol (a sideways 8) with two red lobes or "nuclei." This shape is thought to have arisen because the Infinity Galaxy was formed as two disk galaxies engaged in a head-on collision.
What makes this highly unusual is the fact that this black hole sits between the two colliding galaxies in a vast cloud of gas, rather than in either respective nucleus. From its perch between these galaxies, the black hole now feeds greedily on that gas, but researchers think that same cloud also once birthed it. That would make this the first observational evidence of the direct collapsepathway of black hole birth.
The researchers behind these findings uncovered the Infinity Galaxy while examining images from the JWST's 255-hour treasury COSMOS-Web survey. In addition to the suspected direct collapse black hole that sits between the colliding galaxies, the team found that each nucleus of those galaxies also contains a supermassive black hole!
"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," team leader and Yale University researcher Pieter van Dokkum said in a statement. "The biggest surprise of all was that the black hole was not located inside either of the two nuclei but in the middle.
"We asked ourselves: How can we make sense of this?"
van Dokkum explained that finding a black hole not in the nucleus of a massive galaxy isn't, in itself, unusual. What is strange is the question of how that black hole got there.
"It likely didn't just arrive there, but instead it formed there," van Dokkum said. "And pretty recently. In other words, we think we're witnessing the birth of a supermassive black hole – something that has never been seen before."
This discovery could solve an intriguing mystery regarding the observation of supermassive black holes with masses millions or billions of times that of the sun, less than 1 billion years after the Big Bang.
Black holes could skip stellar deaths and supernovas
Since it began operating three years ago, the JWST has delivered something of a conundrum to cosmologists; observations that show supermassive black holes seem common as early as 500 million years after the Big Bang.
That's a problem because it was previously proposed that supermassive black holes form through successive mergers of smaller black holes. However, beginning this process with so-called stellar-mass black holes would require waiting for the first generation of stars to form, live their lives, then collapse in supernova explosions. The resulting black holes would have to undergo a series of mergers and periods of intense feeding upon interstellar gas and dust.
This process would take at least a billion years to "grow" a black hole to supermassive status. Thus, seeing a multitude of supermassive black holes before the universe was 1 billion years old is problematic.
That is, unless these bodies got a head start by skipping the stellar life and birth stage of this process.
"How supermassive black holes formed is a long-standing question. There are two main theories, called 'light seeds' and 'heavy seeds.' In the light seed theory, you start with small black holes formed when a star's core collapses and the star explodes as a supernova," van Dokkum explained. "That might result in a black hole weighing up to about 1,000 suns. You form a lot of them in a small space, and they merge over time to become a much more massive black hole."
As mentioned above, the problem with that is the time this process would take and the JWST's discovery of incredibly massive black holes at early stages of our 13.8 billion-year-old universe.
Black holes could have heavy seeds
Alternatively, the heavy seed theory sees supermassive black hole growth kickstarted with a much larger black hole, maybe up to one million times the mass of the sun. This forms directly from the collapse of a large gas cloud.
"You immediately form a giant black hole, so it's much quicker. However, the problem with forming a black hole out of a gas cloud is that gas clouds like to form stars as they collapse rather than a black hole, so you have to find some way of preventing that. It's not clear that this direct-collapse process could work in practice," van Dokkum said. "By looking at the data from the Infinity Galaxy, we think we've pieced together a story of how this could have happened here."
The researchers suggest that as the two disk galaxies collided, a ring structure of stars, visible in the JWST image, was formed. During this collision, gas within these two galaxies would have been shocked and compressed. They think this compression may have been so extreme that it formed a "dense knot" in the gas, which then collapsed into a black hole.
As van Dokkum explained, there is a wealth of circumstantial evidence for this formation channel for the black hole in the Infinity Galaxy.
"We observe a large swath of ionized gas, specifically hydrogen that has been stripped of its electrons, that's right in the middle between the two nuclei, surrounding the supermassive black hole," he continued. "We also know that the black hole is actively growing – we see evidence of that in X-rays from NASA'sChandra X-ray Observatory and radio from the Very Large Array. Nevertheless, the question is, did it form there?"
There are two possible explanations that don't involve a direct collapse black hole forming at the intersection of these merged galaxies.
"First, it could be a runaway black hole that got ejected from a galaxy and just happens to be passing through," van Dokkum said. "Second, it could be a black hole at the center of a third galaxy in the same location on the sky. If it were in a third galaxy, we would expect to see the surrounding galaxy unless it were a faint dwarf galaxy. However, dwarf galaxies don't tend to host giant black holes.
"If the black hole were a runaway, or if it were in an unrelated galaxy, we would expect it to have a very different velocity from the gas in the Infinity Galaxy."
To test this, the team intends to measure the velocity of the gas and the velocity of the black hole and compare them. Should those velocities be close, within around 30 miles per second (50 kilometers per second), then van Dokkum asserts that it will be hard to argue that the black hole is not formed from that gas.
"Our preliminary results are exciting. First, the presence of an extended distribution of ionized gas between the two nuclei is confirmed. Second, the black hole is beautifully in the middle of the velocity distribution of this surrounding gas, as expected if it formed there. This is the key result that we were after!" van Dokkum continued. "Third, as an unexpected bonus, it turns out that both galaxy nuclei also have an active supermassive black hole."
Though the team can't say definitively that they discovered a direct collapse black hole, they can state with confidence that this JWST data strengthens the case for this being a newborn black hole, while eliminating some of the counter-explanations to the direct collapse pathway.
"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," van Dokkum said. "We will continue to pore through the data and investigate these possibilities."
Quelle: SC
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Update: 1.08.2025
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NASA’s Webb Traces Details of Complex Planetary Nebula
Since their discovery in the late 1700s, astronomers have learned that planetary nebulae, or the expanding shell of glowing gas expelled by a low-intermediate mass star late in its life, can come in all shapes and sizes. Most planetary nebula present as circular, elliptical, or bi-polar, but some stray from the norm, as seen in new high-resolution images of planetary nebulae by NASA’s James Webb Space Telescope.
Webb’s newest look at planetary nebula NGC 6072 in the near- and mid-infrared shows what may appear as a very messy scene resembling splattered paint. However, the unusual, asymmetrical appearance hints at more complicated mechanisms underway, as the star central to the scene approaches the very final stages of its life and expels shells of material, losing up to 80 percent of its mass. Astronomers are using Webb to study planetary nebulae to learn more about the full life cycle of stars and how they impact their surrounding environments.
Image A: NGC 6072 (NIRCam Image)
First, taking a look at the image from Webb’s NIRCam (Near-Infrared Camera), it’s readily apparent that this nebula is multi-polar. This means there are several different elliptical outflows jetting out either way from the center, one from 11 o’clock to 5 o’clock, another from 1 o’clock to 7 o’clock, and possibly a third from 12 o’clock to 6 o’clock. The outflows may compress material as they go, resulting in a disk seen perpendicular to it.
Astronomers say this is evidence that there are likely at least two stars at the center of this scene. Specifically, a companion star is interacting with an aging star that had already begun to shed some of its outer layers of gas and dust.
The central region of the planetary nebula glows from the hot stellar core, seen as a light blue hue in near-infrared light. The dark orange material, which is made up of gas and dust, follows pockets or open areas that appear dark blue. This clumpiness could be created when dense molecular clouds formed while being shielded from hot radiation from the central star. There could also be a time element at play. Over thousands of years, inner fast winds could be ploughing through the halo cast off from the main star when it first started to lose mass.
Image B: NGC 6072 (MIRI Image)
The longer wavelengths captured by Webb’s MIRI (Mid-Infrared Instrument) are highlighting dust, revealing the star researchers suspect could be central to this scene. It appears as a small pinkish-whitish dot in this image.
Webb’s look in the mid-infrared wavelengths also reveals concentric rings expanding from the central region, the most obvious circling just past the edges of the lobes.
This may be additional evidence of a secondary star at the center of the scene hidden from our view. The secondary star, as it circles repeatedly around the original star, could have carved out rings of material in a bullseye pattern as the main star was expelling mass during an earlier stage of its life.
The rings may also hint at some kind of pulsation that resulted in gas or dust being expelled uniformly in all directions separated by say, thousands of years.
The red areas in NIRCam and blue areas in MIRI both trace cool molecular gas (likely molecular hydrogen) while central regions trace hot ionized gas.
As the star at the center of a planetary nebula cools and fades, the nebula will gradually dissipate into the interstellar medium — contributing enriched material that helps form new stars and planetary systems, now containing those heavier elements.
Webb’s imaging of NGC 6072 opens the door to studying how the planetary nebulae with more complex shapes contribute to this process.
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).
Quelle: NASA
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Update: 3.08.2025
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The Webb space telescope spies its first black holes snacking on stars
The celestial bodies sit in dusty environments that block most other telescopes’ views
The James Webb Space Telescope took its first look at black holes shredding and feasting on stars (illustration shown).
NRAO/AUI/NSF, NASA
The James Webb Space Telescope has taken its first look at black holes secretly snacking on stars within dusty galaxies. JWST’s ability to pick up detailed infrared signals lets it peer past the dust to probe the mostly hidden black holes, researchers report in the Aug. 1 Astrophysical Journal Letters.
A dormant black hole is normally impossible to see. That changes when a star wanders too close. The black hole’s gravity stretches the star into a disk that rotates around and feeds the temporarily awakened giant in a tidal disruption event, or TDE. The disk of star gas heats up and emits X-rays and ultraviolet and visible light, which is how astronomers typically find sleepy black holes.
But “these wavelengths can be basically blocked” if dust shrouds a feasting black hole, says MIT astrophysicist Megan Masterson. Most known TDEs took place in fairly clear environments, but the events probably happen just as often in dusty, obscured galaxies, she and her colleagues recently reported. They’re just harder to see.
That dust, however, gives off its own signals. It releases infrared light after absorbing the gas’s emissions in other wavelengths. In previous work, Masterson and colleagues searched archived data from an infrared-based space survey and spotted 12 probable TDEs.
Masterson and colleagues set JWST’s sights on four of those TDEs. JWST, which sees in a wider range of infrared wavelengths than previous telescopes, detected infrared emissions from atoms that had been stripped of electrons through strong X-ray and ultraviolet radiation. That’s a telltale sign of a dining black hole.
Bright gas disks around fully awake black holes, which feed constantly and are surrounded by dust clumps, could give off similar radiation. But the observed signs of silicate dust looked more like specks swirling around a dormant black hole briefly waking up for a stellar snack, the team found. Computer simulations confirmed that TDEs could explain what JWST saw.
Infrared light emissions are delayed by a few months compared with the typically detected wavelengths because it takes time for the shredded star’s light to reach the dust. But they’re essentially the only way to study feasting black holes blanketed by dust, Masterson says.
Quelle: ScienceNews