Latest news with #MarkHannam
Hindustan Times
22-07-2025
- Science
- Hindustan Times
Violent Collision of Two Black Holes Rippled Across the Universe
Astrophysicists have discovered the largest known merger of two black holes to form a larger single hole about 225 times the mass of the sun. The violent collision between the spinning objects, one about 100 times the mass of the sun and the other about 140 times that amount, produced a gravitational wave that rippled across the universe. Scientists detected the faint signal using the Laser Interferometer Gravitational-Wave Observatory (LIGO), a facility that uses 2.5-mile long, L-shaped instruments in Hanford, Wash., and Livingston, La., in unison to detect and measure cosmic gravitational waves. The signal, only 0.2 second long, was picked up in 2023 and announced July 13 at a conference in Glasgow. The findings have been posted ahead of peer review on the preprint server arXiv. A black hole is an astronomical object with a gravitational pull so strong that nothing, not even light, can escape. While scientists have predicted the existence of black holes since the 18th century, direct evidence has only turned up recently. In 2015, scientists used the LIGO to make the first-ever detection of a gravitational wave, a distortion in the fabric of space caused by the acceleration of massive objects such as black holes or neutron stars. Gravitational waves carry information about their origins and the nature of gravity itself. The effort won the researchers a Nobel Prize in 2017. In 2019, scientists released the first image of a black hole at the center of a galaxy roughly 55 million light years from Earth, showing a fuzzy ring of oranges and yellows surrounding a dark center, where light is trapped by the object's massive gravitational pull. Because the 2023 gravitational wave only produced a small amount of data, scientists don't know exactly how far away the object is. 'It's kind of ridiculous to say, but it's sort of between three or four billion light years away and 12 to 13 billion light years away,' said Mark Hannam, an astrophysicist at the University of Cardiff in the U.K., and a member of the scientific team that discovered the object, named GW231123 for 'gravitational wave' and the date it was discovered. Hannam said there is still a lot that scientists are learning and that the two black holes could have formed through earlier mergers of even smaller black holes. 'We don't know how many black holes were merged in this process,' Hannam said. The two black holes could also have formed from stars colliding and forming more massive, highly spinning stars which then collapsed to form black holes, according to Vicky Kalogera, professor of physics and astronomy at Northwestern University and a member of the team that analyzed the signal. Either way, this finding has opened up new lines of research using gravitational wave detectors, according to Alessandra Corsi, professor of physics and astronomy at Johns Hopkins University who wasn't involved in the paper. 'What excites me is finding different ways of studying the cosmos that are telling you, hey, there's surprising things that are going on,' she said. Write to Eric Niiler at
Yahoo
19-07-2025
- Science
- Yahoo
Scientists measure largest ever collision of two black holes
Two black holes have collided far beyond the distant edge of the Milky Way, creating the biggest merger ever recorded by gravitational wave detectors. The two phenomena, each more than 100 times the mass of the sun, had been circling each other before they violently collided about 10 billion light years from Earth. Scientists at the Ligo Hanford and Livingston Observatories detected ripples in space-time from the collision just before 2pm UK time on 23 November 2023, when the two US-based detectors in Washington and Louisiana twitched at the same time. Alongside their enormous masses, the signal, dubbed GW231123 after its discovery date, also showed the black holes spinning rapidly, according to researchers. 'This is the most massive black hole binary we've observed through gravitational waves, and it presents a real challenge to our understanding of black hole formation,' said Professor Mark Hannam, from Cardiff University and a member of the Ligo Scientific Collaboration. An artist's impression of a black hole using data from Nasa's James Webb Space Telescope (Nasa/JWST) Gravitational-wave observatories have recorded around 300 black hole mergers. Prior to GW231123, the heaviest merger detected was GW190521, whose combined mass was 140 times that of the sun. The latest merger produced a black hole up to 265 times more massive than the sun. 'The black holes appear to be spinning very rapidly — near the limit allowed by Einstein's theory of general relativity,' said Dr Charlie Hoy from the University of Portsmouth. 'That makes the signal difficult to model and interpret. It's an excellent case study for pushing forward the development of our theoretical tools.' 'It will take years for the community to fully unravel this intricate signal pattern and all its implications,' said Dr Gregorio Carullo, assistant professor at the University of Birmingham. 'Despite the most likely explanation remaining a black hole merger, more complex scenarios could be the key to deciphering its unexpected features. Exciting times ahead!" Facilities like Ligo in the United States, Virgo in Italy, and KAGRA in Japan are engineered to detect the tiniest distortions in spacetime caused by violent cosmic events such as black hole mergers. The fourth observing run began in May 2023, and data through January 2024 are scheduled for release later this summer. 'This event pushes our instrumentation and data-analysis capabilities to the edge of what's currently possible,' says Dr Sophie Bini, a postdoctoral researcher at Caltech. 'It's a powerful example of how much we can learn from gravitational-wave astronomy — and how much more there is to uncover.' GW231123 is set to be presented at the 24th International Conference on General Relativity and Gravitation (GR24) and the 16th Edoardo Amaldi Conference on Gravitational Waves, held jointly as the GR-Amaldi meeting in Glasgow, from 14 to 18 July.
The Independent
18-07-2025
- Science
- The Independent
Scientists measure largest ever collision of two black holes
Two black holes have collided far beyond the distant edge of the Milky Way, creating the biggest merger ever recorded by gravitational wave detectors. The two phenomena, each more than 100 times the mass of the sun, had been circling each other before they violently collided about 10 billion light years from Earth. Scientists at the Ligo Hanford and Livingston Observatories detected ripples in space-time from the collision just before 2pm UK time on 23 November 2023, when the two US-based detectors in Washington and Louisiana twitched at the same time. Alongside their enormous masses, the signal, dubbed GW231123 after its discovery date, also showed the black holes spinning rapidly, according to researchers. 'This is the most massive black hole binary we've observed through gravitational waves, and it presents a real challenge to our understanding of black hole formation,' said Professor Mark Hannam, from Cardiff University and a member of the Ligo Scientific Collaboration. Gravitational-wave observatories have recorded around 300 black hole mergers. Prior to GW231123, the heaviest merger detected was GW190521, whose combined mass was 140 times that of the sun. The latest merger produced a black hole up to 265 times more massive than the sun. 'The black holes appear to be spinning very rapidly — near the limit allowed by Einstein's theory of general relativity,' said Dr Charlie Hoy from the University of Portsmouth. 'That makes the signal difficult to model and interpret. It's an excellent case study for pushing forward the development of our theoretical tools.' 'It will take years for the community to fully unravel this intricate signal pattern and all its implications,' said Dr Gregorio Carullo, assistant professor at the University of Birmingham. 'Despite the most likely explanation remaining a black hole merger, more complex scenarios could be the key to deciphering its unexpected features. Exciting times ahead!" Facilities like Ligo in the United States, Virgo in Italy, and KAGRA in Japan are engineered to detect the tiniest distortions in spacetime caused by violent cosmic events such as black hole mergers. The fourth observing run began in May 2023, and data through January 2024 are scheduled for release later this summer. 'This event pushes our instrumentation and data-analysis capabilities to the edge of what's currently possible,' says Dr Sophie Bini, a postdoctoral researcher at Caltech. 'It's a powerful example of how much we can learn from gravitational-wave astronomy — and how much more there is to uncover.' GW231123 is set to be presented at the 24th International Conference on General Relativity and Gravitation (GR24) and the 16th Edoardo Amaldi Conference on Gravitational Waves, held jointly as the GR-Amaldi meeting in Glasgow, from 14 to 18 July.
Yahoo
17-07-2025
- Science
- Yahoo
Scientists record a black hole collision they weren't sure was possible
A pair of newly-discovered record-breaking black holes has scientists simultaneously popping the champagne and scratching their heads. The massive duo are the largest ever recorded at the Laser Interferometer Gravitational-Wave Observatory (LIGO), which was built to detect ripples in the fabric of spacetime caused by the collisions of massive objects. These enormous outliers are challenging theorists to figure out just how they grew to such titanic sizes. 'We don't think black holes form between about 60 and 130 times the mass of the sun, and these two seem to be pretty much slap bang in the middle of that range,' says Mark Hannam, a physicist at Cardiff University in the UK and a LIGO team member. Your normal everyday black hole is thought to be born during the death of a giant star, when the star's weighty core collapses down into an infinitesimal point with such strong gravity that nothing, not even light, can escape it. But the physics of this process gets wonky for especially huge stars. Once their cores weight more than around 60 solar masses, the collapse becomes so violent that the entire star is blown to smithereens, leaving nothing, not even a black hole, behind. Yet LIGO is now spotting more and more black holes within this 'forbidden' zone, including the newest behemoths. They are thought to be 103 and 137 times the sun's mass, according to a paper posted July 13 to but each has enough uncertainty in their measured properties that they could both be inside the prohibited range. When they met and merged out in the deep dark universe billions of years ago, they created an even larger monster tipping the scales at between 190 and 265 solar masses, the most massive beast LIGO has ever seen. As the observatory captures gravitational waves from more such events, researchers will be able to tease apart the mystery of their creation and perhaps learn whether they have a connection to the astoundingly huge black holes lurking in the centers of galaxies. Black holes were thought to come in two flavors. This discovery is a strange third For a long time, black holes were known to come in just two versions—approximately sun-sized and galactic. Most of the roughly 300 black holes LIGO has detected so far fit into the first category: They are between a few and several tens of times the sun's mass and are believed to have formed after a gargantuan star exploded as a supernova, leaving behind a dense remnant that inexorably sucks in anything that gets too close. The second version is a much more gargantuan beast. Telescopes have spotted black holes in the centers of nearly every galaxy; gravitational monstrosities weighing 100 million solar masses or more that appear to regulate star formation within these galaxies. Nobody is quite sure how these immense devourers got so big. Did they start out as sun-scale black holes and then somehow grow to extreme size? Or was there another story behind their creation? The existence of black holes in the intermediate range—somewhere between 100 and 100,000 times the sun's mass—would help bridge this gap and perhaps help explain whether small black holes were turning into larger ones. But, until recently, physicists had never seen one. To great fanfare in 2020, LIGO researchers announced that they'd found a black hole duo with masses 66 and 85 times that of the sun, whose smash-up produced a giant with around 150 solar masses. The finding for the first time showed that black holes could cross into this threshold of intermediate mass, though theorists are still debating exactly how that happened. The problem is that when a gigantic star has a core that weights between 60 and 130 times the sun's mass, it can reach blazing temperatures nearing 300 million degrees Celsius during the end of its life. At that point, particles of light spontaneously transform into electrons and their antimatter counterparts, positrons. These particles can no longer hold up the star's heavy outer layers, which come crashing down with such ferocity that the core is completely obliterated. No black hole, or anything else, results. Physicists have speculated about a few possibilities to explain what they're seeing with LIGO. For one, their theories of stellar evolution might be wrong and perhaps something can survive the severe core collapse of humongous stars. The other possibilities involve smaller black holes growing into larger ones via some kind of two-step process, says astrophysicist Priyamvada Natarajan of Yale University in Connecticut. It could be either that two star-sized black holes came together and combined to form heavier behemoths or a small black hole was created and then sucked down gas and dust to balloon into a more massive beast. 'The question is: What are the cosmic environments and conditions where such things can happen?' Natarajan asks. One major clue might lie with the two new objects, which are spinning around like a top at close to the upper limit that scientists think they can spin. They have the fastest rotations of any black hole LIGO has ever seen. Some researchers have posited such spins could arise when smaller black holes meet, merge, and spin each other up. But Natarajan thinks perhaps something else is going on here. Because if the colliding black holes were spinning in opposite directions (and there's a good chance they were) the merger black hole would have produced a slower-spinning object. She favors the idea that smaller black holes were born in dense stellar clusters full of gas and dust. As that star-sized black hole bounced around inhaling material like water going down a drain, it could have grown and spun up to the extreme rotation seen in the new objects. She and her colleagues are working to calculate the exact outcome of such a feasting process in stellar clusters. Scientists aren't done searching for enormous black holes Future upgrades to the LIGO detectors will make them more sensitive, letting them uncover even more enormous black holes and measure their properties more precisely. Along with gravitational wave detectors in Europe, Japan, and eventually India, researchers will be able to pinpoint black hole events better on the night sky, allowing telescopes to scope those areas out and see if there's, for instance, a dense star cluster that might favor one formation mechanism or another. Researchers are also looking forward to instruments such as the Cosmic Explorer and Einstein Telescope, expected to be operational in the mid-2030s or 40s, which will be able to see black hole mergers that occurred much earlier in the universe's history. Such gravitational wave observatories might be able to capture events when galaxies were first forming, potentially providing insights into how their central black holes became so gargantuan, along with better data on small and intermediate black holes. 'There's just so many black holes littered in the universe,' says Natarajan. 'The fact that we're starting to bridge these scales, I think that's super exciting.' 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NDTV
17-07-2025
- Science
- NDTV
How The Largest Black Hole Merger In History Challenges Its Physics
Astronomers have detected the largest black hole merger ever, and it has challenged their understanding of such formations. The event, designated GW231123, was initially detected on November 23, 2023, by the LIGO-Virgo-KAGRA (LVK) Collaboration. Two enormous black holes, around 100 and 140 times the mass of the Sun, collided in this cosmic collision to create a new black hole - 225 times more massive than the Sun, per the Astronomy Magazine. Since supernova physics usually disturbs progenitor stars in the 60-130 solar mass "mass gap," black holes in that range are not likely to develop via regular stellar collapse. And GW231123 stands out among those 300 black hole mergers for reasons other than simply being the greatest massive collision. "This is the largest and most massive black hole binary ever detected through gravitational waves, and it poses a real challenge to our understanding of black hole formation," LIGO Scientific Collaboration member Professor Mark Hannam of Cardiff University asserted. The distance of GW231123 from Earth is unknown; it may be as far away as 12 billion light-years, according to Professor Hannam. The speed at which the two black holes are orbiting one another is another unexpected aspect of GW231113. The results showed that the two merging black holes were spinning close to the maximum allowed by general relativity, in accordance with Einstein's theory. It is, thus, quite challenging to extract exact features and to model waveforms with such high angular momentum. The black holes are probably spinning as rapidly as is practically feasible, according to Dr Charlie Hoy of Portsmouth University. "GW231123 poses a serious threat to our knowledge of how black holes emerge," Dr Hoy said. According to Professor Zoltan Haiman of the Institute of Science and Technology Austria, who was not involved in the project, the black holes in GW231123 were therefore thought to be leftovers of one or even several generations of previous mergers. GW231123 was discovered by a group of astronomers when the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected faint ripples in space-time caused by two black holes colliding. Scientists refer to these disturbances as gravitational waves. The event was detected during the fourth observing run of the LIGO-Virgo-KAGRA (LVK) network, which consists of Japan's KAGRA, the Virgo detector in Italy, and the LIGO observatories in the United States, CNN reported. GW190521, which was only 60 per cent as large as GW231123, held the previous record for the largest black hole merger ever recorded. In the future, scientists may discover even more gigantic mergers.
