Category: black holes

A mysterious hum of gravitational waves that fills the cosmos may be the echo of "dark stars" that served as the seeds of the first supermassive black holes.

These low-frequency gravitational waves were detected back in 2023 using an array of cosmic lighthouses, or pulsars, in a so-called "pulsar timing array." Pulsars are neutron stars that spin rapidly and regularly while blasting out collimated beams of radiation from their poles that can be used to detect tiny fluctuations in space and time. Such fluctuations are caused by the gravitational waves, or ripples in spacetime.

For a long time, the source of this particular low-frequency gravitational wave background has been somewhat shrouded in mystery, but scientists have hoped that they may be encoded with the secrets of the universe as it was around 13 billion years ago. Indeed, the team behind this research believes this hum of spacetime ripples could help explain how supermassive black holes grew so rapidly before the universe was even a billion years old. They link this solution to hypothetical supermassive "dark stars" that may have collapsed and died in the early universe to birth massive black hole seeds, giving supermassive black hole growth a head start.

"Dark stars were originally proposed as objects that might be seen directly at cosmic dawn," Ilie said. "This work points to a completely different way of testing their possible role in cosmic history," team member Cosmin Ilie of Colgate University said in a statement. "Their descendants could leave a gravitational-wave imprint that persists all the way to the present-day universe."

Cosmic clocks and collapsing Dark Stars

Pulsar timing arrays detect gravitational waves when their passage squashes and stretches space as the waves ripple past them, causing tiny delays in the pulsars' beams of radiation reaching Earth.

Detecting a gravitational wave background, however, required monitoring pulsar timing arrays for many years.

"Pulsar timing arrays are usually thought of as probes of supermassive black-hole binaries in the relatively recent universe," Ilie said. "What our work shows is that the signal may also contain information about how the ancestors of those black holes formed at cosmic dawn.

"In that sense, gravitational waves observed today could provide a new window onto the birth of the first supermassive black holes."

The currently favored explanation for this background is a cosmic history of binary black holes spiraling together before merging, particularly pairings with combined masses of over 1 billion times the mass of the sun.

However, that doesn't explain where these supermassive black holes came from and how the James Webb Space Telescope (JWST) is routinely detecting them before the universe was even 1 billion years old — despite the fact that the feeding and merger chains proposed to create supermassive black holes should take over 1 billion years.

Ilie and his Colgate University colleague Sohan Ghodla questioned if supermassive balck hole growth began with heavy seeds, and if these heavy seeds were created by the collapse of dark stars.

Dark stars are hypothetical primordial stars that, rather than producing energy through nuclear fusion, are instead powered by self-annihilating dark matter within their cores. As dark matter fuels these primordial stars, they would remain cool compared to other stellar bodies, allowing them to continue to accrete matter throughout their lives.

This process would continue until Dark Stars reached masses millions of times that of the sun and collapsed under their own gravity, creating massive black holes; seeds that collide and merge to form supermassive black holes.

Ilie and Ghodla modeled the environment in which the resultant black hole seeds would exist and merge, calculating merger rates and the influence on the gravitational wave background.

They found supermassive dark star remnants could indeed provide a major, perhaps dominant, contribution to the gravitational wave background detected in 2023. That means the measurements provided by pulsar timing arrays could help determine how abundant heavy black hole seeds were in the early universe.

"Produce too many of these massive seeds, and you end up over-producing the pulsar timing array-detected signal," Ghodla said. "Produce too few, and you need other sources to efficiently assemble these supermassive black holes later in the life of the universe to match pulsar timing array observations."

The key determining factor here would be the masses of the dark matter haloes in which the dark stars live and in which the heavy black hole seeds form.

Determining if the researchers' theory is correct may have to wait for improvements in pulsar timing array measurements of the gravitational wave background, along with a better understanding of populations of black holes and their characteristics in the early universe.

The team's research was published on Monday (August 17) in the journal Physical Review D.

Astronomers have discovered that a jet of plasma erupting from a distant supermassive black hole at near-light-speed is being gravitationally lensed by an unseen clump of dark matter. The discovery could tell us about the source of cosmic "ghost" particles called neutrinos.

The supermassive black hole in question is powering a type of quasar called a blazar. All quasars involve supermassive black holes surrounded by vast quantities of material upon which the black holes feed. Material that isn't consumed by these feasting cosmic titans is channeled to the poles of the black holes, from where it is blasted out as plasma jets. A blazar differs from quasars in general because the jets it blasts out are directed at Earth. Blazars, like the one central to this study, designated PKS 2233-148, have long been proposed to be the cosmic particle accelerators that blast out neutrinos.

Neutrinos get their ghostly nickname because they carry no charge and very little mass, meaning that 100 trillion of them can pass through your body every second without you noticing a thing. This makes them hard to both detect and trace back to a source. This gravitationally lensed blazar could assist in that hunt, finally proving blazars are filling the universe with cosmic ghosts.

"These large-scale jets are cosmic accelerators and might be generating neutrinos," Silke Britzen at the Max Planck Institute for Radio Astronomy in Germany told Phys.org. "We study them to search for any peculiarities which might help us to gain a better understanding of neutrino emission."

Blazar jet receives a cosmic course correction

Astronomers have long been interested in PKS 2233-148, identifying this blazar as one that could solidify the link between neutrinos and the jets of feeding supermassive black holes. That is because one of its polar jets is aligned along our line of sight from Earth.

Britzen and colleagues took a new look at observations of PKS 2233-148 made by the Very Long Baseline Array (VLBA) on Earth, the Fermi space telescope, which viewed the blazar in gamma rays, and the X-ray instrument aboard the Swift space observatory.

This revealed how the motion of the jet of PKS 2233-148 changed over time, uncovering hitherto hidden details, including the fact that this blazar jet had been suddenly shifted from its expected path.

"We are very happy to have discovered as-yet-undetected phenomena in the jet, as well as in the gamma-ray light curve," Britzen said.

What could have caused this cosmic course correction? A phenomenon first predicted by Albert Einstein back in 1915 and an unseen cluster of the universe's strangest stuff, dark matter.

What is gravitational lensing and how can dark matter cause it?

The concept of gravitational lensing emerged from Einstein's theory of gravity, general relativity. General relativity states that objects with matter warp the very fabric of space, much like a bowling ball placed on a stretched rubber sheet. Gravity arises from that curvature.

And just as a cannonball would dent that hypothetical rubber sheet more than a bowling ball, an object with greater mass would cause a more extreme warp in space; its gravitational influence is greater.

Something cool happens when light passes this warped space; its usually straight path is curved. This means that when light from a background source passes a massive foreground object acting as a gravitational lens, it arrives at our telescopes at different times, meaning that the background source is magnified or, in extreme cases, can appear in multiple places in the same image.

In this case, it is the jet of PKS 2233-148 that is being lensed. But there is no object of great mass, like a galaxy or galaxy cluster, that can be seen in the right position to be doing the lensing. That leaves the possibility that the lensing body is something that can't be seen at all. Dark matter fits the bill.

Dark matter is effectively invisible because it doesn't directly interact with electromagnetic radiation, or light. In other words, dark matter doesn't emit light, and light doesn't bounce off it. That means even a clump large enough to play the role of a gravitational lens would be undetectable. But that doesn't mean light can't respond to the curvature of space caused by dark matter, just as it does to curvature caused by any body composed of "ordinary" matter like a star or a galaxy.

Like any gravitational lensing set-up, the lensing of the jet of PKS 2233-148 caused by this clump of dark matter requires precise alignment, and that means it is only a temporary thing.

"Because these are short-term phenomena, they are hard to find," Britzen said. "This is the first time that we find a lensing phenomenon which might hint at dark matter substructure."

Britzen and colleagues now hope to find other similar lensing events to further solidify the connection between blazars and neutrino factories.

The team's research was published on July 31 in the journal Monthly Notices of the Royal Astronomical Society.

A trio of heavyweight black holes are entangled in a dance of death that will quite possibly see them gradually all merge to form an even greater behemoth.

Scientists have discovered the black holes in a galaxy that is so far away its light has taken 12.5 billion years to reach us, meaning we see it as it was less than 1.3 billion years after the Big Bang. And it's offering strong supporting evidence that one of the ways black holes grew so massive so quickly in the early universe was through mergers.

"This is the first evidence of three active black holes in a single galaxy in the distant universe," Hannah Übler, an astronomer at the Max Planck Institute for Extraterrestrial Physics in Germany who led the study, said in a statement. "It suggests that processes in the early universe were efficient at bringing massive black holes together, setting the stage for the massive black-hole mergers we expect to detect with future gravitational-wave observatories."

The galaxy that plays host to the black holes is catalogued as J0148-4214 and is so far away (their redshift is 5.0167) that the James Webb Space Telescope (JWST), which made the discovery, could not see the black holes directly. Instead, the Integrated Field Spectroscopy unit on the JWST's Near Infrared Spectrometer (NIRSpec) measured the motion of hydrogen gas swirling around at high velocity in the accretion disks encircling each black hole.

"The JWST data allowed us not only to identify the three black holes, but also to estimate their masses, accretion rates and the stellar mass of the galaxy," Giovanni Mazzolari of the Max Planck Institute for Extraterrestrial Physics said in the statement. "We find a total stellar mass of about 1.3 billion suns, and the black holes represent a significant fraction of that."

Two of the black holes reside at the center of J0148-4214, separated by 620 light-years. One of these black holes has a huge mass of 80 million times the mass of our sun, while its companion is a relative pipsqueak at 600,000 solar masses. Yet despite its diminutive stature, the smaller black hole is growing at a tremendous rate by accreting gas faster than the Eddington limit. This is the theoretical maximum rate at which material can fall towards a black hole; if the rate is any higher then the accretion disk around the black hole becomes so dense and hot that radiation from the disk blows material back out again, stifling the black hole's feeding frenzy. This means the smaller black hole will only be able to keep growing at this rate for a short time before negative feedback calls a halt.

The third black hole is 5,500 light-years out from the center of J0148-4214 and has a mass two million times greater than the mass of our sun. This is about half the mass of the supermassive black hole at the center of our Milky Way galaxy, called Sagittarius A*. It's thought that this third black hole, and quite possibly the second one too, found their way into J0148-4214 via mergers between galaxies.

"These results are extremely exciting," said Roberto Maiolini of the University of Cambridge, who was a participant in the findings. "They suggest that black-hole merging may be an additional, fast route for their rapid growth in the early universe."

Mergers between black holes produce bursts of gravitational waves. Current gravitational-wave detectors — including The Laser Interferometer Gravitational-Wave Observatory (LIGO) in the United States, Virgo in Italy and KAGRA in Japan — are able to detect the high frequency, short wavelength gravitational waves from the mergers of stellar-mass black holes, the kind formed in certain supernova explosions. To detect the much longer wavelength, shorter frequency gravitational waves produced by the merger of supermassive black holes such as those in J0148-4214 requires a space-based detector with a baseline many millions of miles long.

To that end, the European Space Agency plans to launch LISA, the Laser Interferometer Space Antenna. If all goes to plan, by the mid-2030s. LISA will feature three spacecraft in triangular formation, each side of the triangle being 1.55 million miles (2.5 million kilometers) long. The three spacecraft will beam lasers at each other, looking for deviations in the travel time of those laser beams as evidence for the passing of a long-wavelength gravitational wave.

With regards to J0148-4214, however, there is a caveat: The third black hole might not be on a collision course with the other two. Instead, it could be heading out of the galaxy.

It's the classic three-body problem: How do three objects orbiting one another interact?

The two smaller black holes may have entered J0148-4214 as a binary pair. Then, as they were drawn closer to the 80-million-solar-mass black hole, the more massive black hole could have snatched the 600,000-solar-mass black hole while exchanging angular momentum with the two-million-solar-mass black hole to fling it away at high velocity. We see a similar effect in our galaxy with hypervelocity stars that are racing out of the Milky Way. These speedy stars used to be part of a binary pair of stars that got too close to Sagittarius A*, which is the black hole at the center of our galaxy. One half of the binary was captured by the black hole and the other was flung away.

Currently, there is no way to measure the direction of motion of the third black hole in J0148-4214 and confirm whether it will merge with the other two black holes or escape. If it did escape, it could still be wandering alone and dark in intergalactic space even now, 12.5 billion years later.

The findings are presented in the journal Astronomy & Astrophysics.

Supermassive black holes are best known for their immense gravity, pulling in everything that strays too close, even light. But new research suggests these cosmic giants can also hurl enormous amounts of energy outward, driving powerful disturbances that ripple hundreds of thousands of light-years through space.

A study led by Satoshi Yamada of Tohoku University in Japan found that winds generated by an actively feeding supermassive black hole are about 100 times more powerful than astronomers previously estimated.

These outflows, scientists say, inject an amount of energy comparable to several billion supernova explosions, driving turbulence through hot gas across distances of roughly 300,000 light-years —far beyond the boundaries of the host galaxy itself.

"Black holes are largely known for sucking matter in, but they also eject gas in the form of powerful winds," Yamada said in a statement. "These winds were thought to be contained within the galaxy, but our study revealed that the force is immensely more powerful than previously understood."

To measure the extent of those outflows, Yamada and his colleagues observed H1821+643, a bright quasar in the constellation Draco about 3.4 billion light-years from Earth. The galaxy hosting H1821+643 sits at the center of a dense galaxy cluster and harbors an active supermassive black hole estimated to be three to four billion times the mass of the sun.

During a weeklong observation in September 2024, Yamada and his team used XRISM, the X-ray satellite launched by Japan's space agency in 2023, to track the chemical signature of ionized iron atoms in the surrounding hot gas. By examining how the light from these iron ions stretched and broadened, the researchers were able to determine how fast the gas was moving and how turbulent it had become, according to the statement.

The observations revealed that the turbulence is driven by energy released from the quasar, with its effects reaching distances of about 300,000 light-years from the black hole, the study notes.

The result builds on years of observations of H1821+643, which is, in fact, the closest known quasar to Earth located within a galaxy cluster, according to NASA.

One of the more intriguing discoveries came in 2022, when observations of the black hole's spin using NASA's Chandra X-ray Observatory showed it rotates half as quickly as its smaller peers, which spin close to the speed of light.

"The million-dollar question is, why?" Christopher Reynolds, an astronomer at the University of Cambridge and co-author of the 2022 study, said in a statement at the time.

According to that study, one leading hypothesis is that giants like H1821+643 grew primarily through repeated mergers with other black holes arriving from different directions. Those chaotic collisions may have repeatedly disrupted the black hole's rotation instead of steadily spinning it up through a long-lived accretion disk.

While the exact origin of its sluggish spin remains an open question, the black hole's influence clearly extends far beyond its host galaxy.

"For the first time, we have shown that black holes influence the broader cosmic environment through a shock wave of astonishing power," Yamada said in the statement.

"Black holes are key drivers of gas flows and motion in space, transporting vast amounts of energy to different regions of the cosmos."

This research is also described in a paper published July 28 in the journal Nature Astronomy.

Astronomers have used the Very Large Telescope (VLT) to observe the violent outflow of material from a distant black hole. The observation once again shows that even the hungriest black holes are extremely messy eaters, while also revealing the "digestive processes" of these cosmic titans in unprecedented detail.

The research focuses on the black hole system Swift J1727.8−1613, located around 8,800 light-years away, and a violent bout of cosmic indigestion and the bright eruptions the system triggered back in 2023. That episode is what initially led to the discovery of Swift J1727.8−1613 in 2023, and it resulted in the system becoming one of the brightest X-ray sources in the sky over Earth.

A team of astronomers has now discovered that as this black hole greedily stripped a star of its stellar material, some of this matter was consumed, but other stellar material was blasted back into space as high-speed jets and powerful black hole winds. They also found that the most massive outflows of material happened when the black hole's feeding activity was much lower than previously thought. The upshot of this is the conclusion that black holes aren't quite the "bottomless pits" scientists had assumed, but are far more like complex cosmic digestive systems.

"People often imagine black holes simply swallowing everything around them," team leader Noel Castro Segura of the University of Warwick in the UK said in a statement. "What we're seeing is a much more complex process. Matter falls in, the system processes it, and a surprising amount is expelled again."

The changing face of a feeding black hole

Swift J1727.8−1613 consists of a black hole surrounded by a swirling platter of material pulled away from a companion star. This matter still has angular momentum, or rotation, so it can't directly fall to the black hole, but instead forms this structure, called an accretion disk.

The immense gravitational influence of the black hole generates intense tidal forces and friction in the accretion disk, superheating it and causing it to glow brightly.

The observations of this glowing disk conducted by Segura and colleagues differ from previous studies of black hole outbursts because their detailed study allowed them to watch the Swift J1727.8−1613 system change over time as it fed on a star.

The resulting "movie" of this feeding black hole revealed that as the cosmic titan blasted out jets, the accretion disk slowly feeding it underwent changes of its own.

That gives scientists a rare and fleeting insight into the connection that exists between matter falling to the maw of a black hole and the material being blasted out at near light-speed as jets of plasma.

The team also found that even after the feeding frenzy of this black hole had subsided, it seemed to still be powering black hole winds of dense gas. They suggest that the amount of material flung away by the black hole may eventually amount to the same mass as that consumed by the black hole, meaning half of its stellar meal was eventually lost to space.

"If black holes can continue shedding material even after their largest outbursts, it means they may be much less efficient eaters than we previously assumed," Segura added. "A significant fraction of the meal may never reach the black hole at all, changing our understanding of how binary stars in galaxies evolve."

The fact that this team was able to observe the entire feeding cycle of this black hole from its initial flare to its dramatic and rather windy end paints a clearer and more dynamic picture of this process than scientists have ever had access to before.

"We usually gravitate towards the dramatic fireworks when a black hole outburst begins, but our observations show that the finale can be just as intense," Kyle Solomons, Doctoral Researcher at the University of Cape Town, said.

The team's research was published on Wednesday (July 29) in the Monthly Notices of the Royal Astronomical Society (MNRAS).

Some of the brightest objects in the universe may also hold the key to understanding how galaxies evolve — especially when gravity transforms them into giant cosmic magnifying glasses.

Using artificial intelligence to search through data from the Dark Energy Spectroscopic Instrument (DESI), astronomers have identified seven promising candidates for quasars acting as gravitational lenses — natural cosmic magnifying glasses created when a massive object's gravity bends and magnifies light from a more distant object.

These unusual systems could help researchers better understand how actively growing supermassive black holes evolve, according to a statement from Ohio State University.

"Quasars are like the baby pictures of a supermassive black hole," Everett McArthur, lead author of the study and a graduate student in astronomy at The Ohio State University, said in the statement. "So exploring how we get from quasars to those black holes is really important."

Quasars are the intensely bright centers of galaxies powered by actively feeding supermassive black holes. Studying these objects can help researchers understand how black holes evolve into the enormous ones found throughout the modern universe. But as these black holes pull in gas and dust, they release so much energy that they can outshine their entire host galaxies, making those galaxies difficult to study.

Rare cases where a quasar acts as a gravitational lens offer a way around that problem, giving astronomers a unique opportunity to observe both the quasar and the distant galaxy whose light is magnified by its gravity.

However, finding these rare alignments can be exceptionally challenging. To uncover them, the research team began with a catalog of roughly 800,000 quasars identified by DESI and used a machine-learning model to search for subtle signatures of gravitational lensing.

Because so few quasars acting as gravitational lenses are known, researchers had little real-world data to train their AI model. Instead, they generated simulated examples of these cosmic alignments, allowing the algorithm to learn what to look for before searching the DESI catalog. The algorithm narrowed the search to about 200 candidates, which researchers then reviewed manually. That process resulted in seven new quasar lens candidates.

The discoveries roughly double the number of known systems found through similar survey searches, according to the statement.

While artificial intelligence played a key role in finding the candidates, the discoveries highlight the scientific potential hidden within the massive datasets produced by modern astronomy. DESI is mapping millions of galaxies and quasars, creating an enormous archive that would be nearly impossible to search by hand.

Follow-up observations will be needed to confirm the newly identified quasar lenses and study their properties in greater detail. If verified, they could offer astronomers a powerful new way to investigate how supermassive black holes shaped the galaxies around them while demonstrating how AI can uncover rare cosmic phenomena hidden within the enormous datasets produced by modern sky surveys.

Their findings were published July 22 in The Astrophysical Journal.

Using NASA's Chandra X-ray space telescope, astronomers have spotted the blisteringly hot exhaust fumes of one the earliest quasars, cosmic "breath" with temperatures as great as 36 million degrees Fahrenheit. This intensely bright titan is powered by a feeding supermassive black hole engine.

The Chandra X-ray telescope observed a relatively silent quasar that existed 2.1 billion years after the Big Bang. The cosmic "exhaust fumes" from this black hole engines extend out for around 100,000 light-years around a quasar at the heart of a still-forming galactic cluster, or "proto-cluster" called MQN01. These blisteringly hot gas structures will eventually become the atmospheres that envelope modern clusters of galaxies, known as the intracluster medium (ICM).

Thus, this research reveals for the first time the exact moment in cosmic history that these galactic atmospheres began to form and gather.

"The central scientific question is to understand how this hot phase forms: what are the physical conditions of the gas during its formation and what processes contribute to its heating," team member Sebastiano Cantalupo of the University of Milan-Bicocca said in a statement.

"[The data] show extraordinary properties of the gas that could provide us with the first insights into how this hot phase of the circumgalactic medium, which we now see as intracluster medium, formed."

Start your engines...

The team behind this research spotted this hot gas structure after 180 hours of X-ray observations conducted by Chandra. Until now, X-ray detections such as this have only been made for quasars that sit in active galactic nuclei (AGNs) at the heart of "radio-loud" galaxies.

The X-ray emissions from these radio galaxies come from jets of particles blasted out from around feeding supermassive black holes at near-light speeds.

But the quasar at the heart of MQN01 differs from these because it is radio-quiet. This means the X-rays detected by Chandra from this quasar are uncontaminated by plasma jets, so the observation is entirely the result of the cosmic "motorbreath" from the quasar.

"We are facing one of the most distant detections of extended thermal X-ray emission associated with the formation of hot gas in dense regions of the universe, which will likely evolve into the known local ICM," Cantalupo said.

"We believe we have identified a phase in its life in which cold gas falls towards the gravitational potential of this massive halo and is heated by gravitational shocks, reaching temperatures of about 20 million Kelvin [36 million degrees Fahrenheit (20 million degrees Celsius)].

"The densities and pressures we measured are high: one to two orders of magnitude higher than those of clusters in our local universe."

The observations of this radio-quiet galaxy were possible thanks to the application of a technique usually used to analyze Seyfert galaxies, which host feeding supermassive black holes in the local universe (the area of space found within 1 billion light-years of Earth). The challenge the team faced was isolating the faint light from the gas from the blinding glare of gas closer to the central black hole.

"We were initially extremely skeptical ourselves," team leader Andrea Travascio of the INAF said. "Given the exceptional nature of the data, we sifted through every alternative explanation: from artificial outflows to instrumental contamination or other unsuspected effects. But each alternative scenario encountered insurmountable theoretical limitations. The thermal explanation is the only one consistent with the physical data."

Travascio and the team are now analyzing archival datasets from hundreds of other quasars to discover if this heating phase is common to protoclusters or if MQN01 is a rarity.

"Considering how unique the result was and also taking into account Chandra's technical difficulties in the final phases of its mission, the satellite has once again demonstrated its extraordinary ability to produce scientifically relevant results even after decades of operation," Travascio said.

The team's research was published on Friday (July 24) in the journal Astronomy & Astrophysics.

Using the Chandra X-ray spacecraft, astronomers have seen a supermassive black hole jet churning and "cooking" gas surrounding a galaxy nicknamed the "red potato." And this potato is seen as it was when the universe was around 2 billion years old.

The galaxy in question is officially designated MQN01 J004131.9-493704 and is located about 11.7 billion light-years from Earth at the intersection of a vast cosmic web along which galaxies formed in the early universe. Originally discovered by the James Webb Space Telescope (JWST), the odd, blob-like appearance of the galaxy is why it has such a peculiar nickname.

The red potato sits in a cosmic "pot" of cold and dense gas. This is a little puzzling, as this should mean that stars are actively forming around it, but that isn't happening. New research offers an explanation: a supermassive black hole in the vicinity of the red potato is churning and heating the galaxy's pot of gas. This could be preventing the gas from cooling and collapsing to birth stellar bodies.

“Stars are not forming like we thought they would, so we went searching for the reason why," team leader Weichen Wang of the University of Milan-Bicocca in Italy said in a statement. "We found there may be a cook in this cosmic kitchen."

An unexpected chef

A supermassive black hole's interference with the red potato was first indicated by the fact that its surrounding gas is unexpectedly turbulent in comparison to similar gas clouds around similar galaxies.

Wang and colleagues set about hunting for the source of this turbulence with Chandra. That's when they found a black hole jet pointed toward the red potato, which they reasoned must be slamming into this ancient galaxy's gas envelope.

"If the black hole's jet is stirring up the gas around the red potato, it could greatly slow down how quickly the galaxy can acquire new, fresh material to form stars," team member Sebastiano Cantalupo of the University of Milan-Bicocca said in the statement. "With the energy from the stirring, the galaxy will starve and not be able to produce new stars at the rate expected for similar galaxies at the same cosmic epoch."

The meddling supermassive black hole is located in a galaxy around 200,000 light-years from the red potato, and this galaxy is actually very actively forming new stars. Indeed, other galaxies in the vicinity of the Red Potato are also birthing new stars.

This discovery, as part of some of the first research to investigate the behavior of gas around non-star-forming galaxies, could be vital in improving our understanding of how neighboring galaxies interact and, occasionally, interfere with each other's evolution.

"The red potato is leaving crumbs of information that may help us track down the answers to some really big questions," team member Andrea Travascio, also of the University of Milan-Bicocca, said. "Quite an important job for a galactic spud like this."

The team's research was published on July 7 in the journal Astronomy & Astrophysics.

Fixing a problem inside one of the world's most sophisticated scientific observatories might seem like the kind of challenge that demands a multimillion-dollar upgrade or revolutionary new technology.

But for scientists working on the Laser Interferometer Gravitational-Wave Observatory (LIGO), which listens for ripples in spacetime generated by cosmic collisions like merging black holes, the solution to a mild but persistent engineering challenge turns out to be as simple as an off-the-shelf camera.

By pairing commercially available thermal imaging cameras with computer models, a team led by Jonathan Richardson at the University of California, Riverside, has developed a technique that corrects tiny, heat-induced distortions in the observatory's mirrors — an elusive flaw that scientists say currently limits how far into deep space the facility can look.

"It doesn't require any new technology development, which is almost unheard of for solving a LIGO instrumentation problem," Richardson said in a statement.

Once incorporated into LIGO's upcoming upgrade, Richardson and his team estimate the fix would extend the observatory's reach by roughly 33 million light-years.

That gain might sound like a drop in the ocean against the unimaginably vast scale of the universe, but because space expands in three dimensions, pushing a detector's reach even slightly opens up an exponentially larger window of space. Being able to look further into the universe will allow astronomers to "hear" many more cosmic ripples, in turn increasing the potential for discovering the universe’s most violent collisions that lie beyond LIGO's reach today.

LIGO detects these cosmic ripples, known as gravitational waves, using twin L-shaped facilities in the U.S. — in the states of Washington and Louisiana. Inside each detector, a laser beam shoots down two 2.5-mile-long (4-kilometer-long) tunnels, bouncing off pristine mirrors at each end. When a gravitational wave passes through Earth, it subtly stretches one tunnel and squeezes the other. That microscopic shift alters the laser beams ever so slightly, producing a tiny flicker of light that alerts scientists to a distant cosmic event.

Because these cosmic signals are inconceivably small, preserving every single photon is crucial. To accomplish this, LIGO relies on mirrors polished to reflect 99.9999%t of the laser light that strikes them, ranking them among the purest optical components ever built.

Yet even these near-perfect mirrors have had one unavoidable flaw. The mirrors still absorb a tiny fraction of that intense laser light. That energy turns into heat, warping the mirror's surface by just a few nanometers, enough to distort the laser beam and reduce the observatory's overall sensitivity.

Physicists already knew they could counteract these distortions by applying targeted heat to the back of the mirrors. The difficult part was measuring the distortions accurately enough such that the correcting heat could be applied with exact precision.

The new technique uses infrared thermal images and existing computer models to reconstruct a map of distortions across the mirror's surface.

"You can think of it like taking an infrared picture of a car engine," Richardson said in the statement. "An engineer can look at the temperature pattern on the outside and infer what's happening inside the engine. We're doing the same thing with LIGO's mirrors."

And the technique isn't just a fix for LIGO. It is also expected to become part of the foundational design for Cosmic Explorer, a proposed next-generation U.S. gravitational-wave observatory targeted for the mid-2030s.

With 25-mile-long (40-km-long) arms — 10 times larger than LIGO's — Cosmic Explorer is already designed to detect gravitational wave events far beyond the reach of today's observatories. This new technique will only supercharge its ultimate reach.

"The goal for the next generation of gravitational-wave detectors is to achieve about 10 times the sensitivity of today's instruments," Richardson said in the statement. "One of the key obstacles to achieving that is reducing the fundamental quantum mechanical noise that limits the precision of the measurements."

The technique is described in a paper published July 16 in Classical and Quantum Gravity.

The launch of NASA's next super telescope, the Nancy Grace Roman Space Telescope (Roman), may mean there is nowhere left for violent black holes to hide.

In fact, these cosmic cannibals may not even be able to hide from Roman at "cosmic noon," a period of the universe's history that occurred around 11 billion to 12 billion years ago. The study of these gory stellar events so early in the history of the universe could help reveal how supermassive black holes grew so big, so rapidly.

Occurrences of black holes ripping apart stars are called tidal disruption events (TDEs), and they happen when an unfortunate star's orbit brings it too close to the immense gravitational influence of a supermassive black hole. This simultaneously squashes and squeezes the star in a process called "spaghettification," with plasma pasta wrapping around the black hole and being fed gradually to it.

Because supermassive black holes are wrapped in a one-way, light-trapping boundary called an event horizon, the only way to study them is when they are actively consuming surrounding matter. Such matter swirls around them in what are known as accretion disks.

However, lighter supermassive black holes aren't ravenous feeders, making them harder to investigate. That is, until a star gets too close and is shredded in an incredibly bright TDE that can outshine the combined light of every star in the supermassive black hole's host galaxy. TDEs are more common to supermassive black holes with masses of about 100,000 to 100 million suns, because supermassive black holes with masses over 1 billion solar masses tend to immediately swallow their stellar snacks.

Previous research has suggested TDEs wouldn't be common in the early universe, because the first supermassive black holes wouldn't even have a mass of 100,000 times that of the sun and thus wouldn't shred stars. However, a new study has reassessed the frequency of TDEs around 1 billion to 2 billion years after the Big Bang, finding they could be more common than previously estimated. Especially during the crowded conditions found during cosmic noon.

Set to launch on Aug. 30, 2026, scientists are hoping Roman's High-Latitude Time-Domain Survey, which will repeatedly revisit a region of the sky equivalent to 90 full moons, will be a powerful tool in the hunt for TDEs in the early universe and their subsequent study. This team estimated that Rubin will detect thousands to tens of thousands of TDEs each year, with 100s dating back to cosmic noon.

"The Roman Space Telescope is going to be transformative for transient science [transients are astronomical events that light up the sky then fade away]," research team leader Mitchell Karmen of the Johns Hopkins University said in a statement. "Thanks to Roman's high sensitivity, we can find multiple tidal disruption events out to greater distances and earlier cosmic times than ever before."

This means Roman is ideally poised to solve a puzzle that has developed since its predecessor, the James Webb Space Telescope (JWST), began beaming data back to Earth in July 2022.

How could early TDEs solve the puzzle of black hole growth

Supermassive black holes with masses equivalent to millions or even billions of suns are found at the hearts of all large galaxies. When they are seen in the relatively local universe, that isn't so problematic; they have had plenty of time to grow via mergers and feeding.

However, the JWST has been routinely spotting supermassive black holes prior to the universe being even 1 billion years old. That is troubling because these early black holes should have had to undergo at least 1 billion years of mergers and gluttonous feeding to reach supermassive status. Scientists have two prevailing theories as to how this growth may have happened.

The first suggests supermassive black holes grow from "light seeds," beginning with black holes with masses just a few hundred times that of the sun that are born from the death and collapse of massive stars.

Such black holes might weigh up to a few hundred times the mass of the sun. These black holes would then merge over time, as well as consume surrounding gas at an incredible rate that facilitates rapid growth. For this theory to be the right one, every young galaxy would have to harbor a massive black hole at its center.

The second theory suggests early supermassive black holes grew from "heavy seeds" created directly from the collapse of vast clouds of primordial gas and dust. This would allow rapid growth because black holes could begin the whole merger and feeding process before the first stars lived and died.

Should this be the correct pathway, however, the fact that collapse events would be rare would make massive black holes at the heart of cosmic noon galaxies less common.

Because TDEs are common to less massive supermassive black holes, counting their occurrence at cosmic noon could give an indication of the masses of black holes during that epoch — the key to determining between heavy seeds and light seeds.

"Tidal disruption events help us probe the population of light supermassive black holes, which can help us discriminate between these models," Karmen said.

"Just by counting the number of TDEs as a function of redshift [a measure of cosmic distance], you can put meaningful constraints on the population of million-solar-mass black holes. Roman will be transformative in that it can probe tidal disruption events out to greater distances, so you can look at how the rate of TDEs evolves over time," team member Suvi Gezari, an associate professor of astronomy at the University of Maryland, said. “Just like the JWST has transformed our understanding of distant, high-redshift [very distant] galaxies, Roman is poised to transform our understanding of high-redshift transients."

The team's research was published on July 14 in The Astrophysical Journal.