{"683133":{"#nid":"683133","#data":{"type":"news","title":"LIGO Detects Most Massive Binary Black Hole to Date","body":[{"value":"\u003Cp dir=\u0022ltr\u0022\u003EThe\u0026nbsp;\u003Ca href=\u0022https:\/\/www.ligo.caltech.edu\/news\/ligo20240405\u0022\u003ELaser Interferometer Gravitational-Wave Observatory (LIGO)\u2019s LIGO-Virgo-KAGRA (LVK) collaboration\u003C\/a\u003E has detected an extremely unusual binary black hole merger \u2014 a phenomenon that occurs when two black holes are pulled into each other\u0027s orbit and combine. Announced yesterday in a\u0026nbsp;\u003Ca href=\u0022https:\/\/www.caltech.edu\/about\/news\/ligo-detects-most-massive-black-hole-merger-to-date\u0022\u003ECalifornia Institute of Technology press release\u003C\/a\u003E, the binary black hole merger, GW231123, is the largest ever detected with gravitational waves.\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003EBefore merging, both black holes were spinning exceptionally fast, and their masses fell into a range that should be very rare \u2014 or impossible.\u0026nbsp;\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003E\u201cMost models don\u0027t predict black holes this big can be made by supernovas, and our data indicates that they were spinning at a rate close to the limit of what\u2019s theoretically possible,\u201d says\u003Cstrong\u003E\u0026nbsp;\u003C\/strong\u003E\u003Ca href=\u0022https:\/\/physics.gatech.edu\/user\/margaret-millhouse\u0022\u003E\u003Cstrong\u003EMargaret Millhouse\u003C\/strong\u003E\u003C\/a\u003E, a research scientist in the\u0026nbsp;\u003Ca href=\u0022https:\/\/physics.gatech.edu\/\u0022\u003ESchool of Physics\u003C\/a\u003E who played a key role in the research. \u201cWhere could they have come from? It raises interesting questions.\u201d\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003EA binary black hole merger absorbs characteristics from both of the contributors, she adds. \u201cAs a result, this is not only the most massive binary black hole ever seen but also the fastest-spinning binary black hole confidently detected with gravitational waves.\u201d\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003E\u201cGW231123 is a record-breaking event,\u201d says School of Physics Professor\u0026nbsp;\u003Ca href=\u0022https:\/\/physics.gatech.edu\/user\/laura-cadonati\u0022\u003E\u003Cstrong\u003ELaura Cadonati\u003C\/strong\u003E,\u003C\/a\u003E who has been a member of the\u0026nbsp;\u003Ca href=\u0022https:\/\/www.ligo.caltech.edu\/page\/ligo-scientific-collaboration\u0022\u003ELIGO Scientific Collaboration\u003C\/a\u003E since 2002. \u201cLIGO has been observing the cosmos for 10 years now. This discovery underscores that there is still so much that this instrument can help us learn.\u201d\u003C\/p\u003E\u003Ch3\u003E\u003Cstrong\u003EA Cosmic View\u003C\/strong\u003E\u003C\/h3\u003E\u003Cp dir=\u0022ltr\u0022\u003EThe findings challenge current theories on how smaller black holes form, says School of Physics Assistant Professor and LIGO collaborator\u0026nbsp;\u003Ca href=\u0022https:\/\/physics.gatech.edu\/user\/surabhi-sachdev\u0022\u003E\u003Cstrong\u003ESurabhi\u003C\/strong\u003E\u0026nbsp;\u003Cstrong\u003ESachdev\u003C\/strong\u003E\u003C\/a\u003E. Smaller black holes are the result of supernovae: dying and collapsing stars. During that collapse, explosions can tear apart or eject part of the star\u2019s mass \u2014 limiting the size of the black hole that forms.\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003E\u201cBlack holes from supernovae can weigh up to about 60 times the mass of our Sun,\u201d she says. \u201cThe black holes in this merger were likely the mass of\u0026nbsp;\u003Cem\u003Ehundreds\u003C\/em\u003E of suns.\u201d\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003EBecause of its size, GW231123 also allowed the team to study the merger in unprecedented detail. \u201cLIGO has observed scores of black hole mergers,\u201d says Cadonati. \u201cOf these, GW231123 has provided us with the clearest view of the \u2018grand finale\u2019 of a merger thus far. This adds a new clue to solve the puzzle that are black holes, including their origins and properties.\u201d\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003E\u201cWhile we saw that our expectations matched the data, the extreme nature of this event pushed our models to their limits,\u201d Millhouse adds. \u201cA massive, highly spinning system like this will be of interest to researchers who study how binary black holes form.\u201d\u003C\/p\u003E\u003Ch3\u003E\u003Cstrong\u003EDecoding a Split-Second Signal\u003C\/strong\u003E\u003C\/h3\u003E\u003Cp dir=\u0022ltr\u0022\u003EMillhouse and School of Physics Postdoctoral Fellow\u0026nbsp;\u003Cstrong\u003EPrathamesh Joshi\u003C\/strong\u003E used Einstein\u2019s equations for general relativity to confirm LIGO\u2019s detections.\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003ETo find black holes, LIGO measures distortions in spacetime \u2014 ripples that are created when two black holes collide. These patterns in gravitational waves can be used to find the signature signal of black hole collisions.\u0026nbsp;\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003E\u201cIn this case, the signal lasted for just one-tenth of a second, but it was very clear,\u201d says Joshi. \u0022Previously, we designed a special study to detect these interesting signals, which accounted for all the unusual properties of such massive systems \u2014 and it paid off!\u201d\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003E\u201cTo ensure it wasn\u2019t noise, the Georgia Tech team first reconstructed the signal in a model-agnostic way,\u201d Millhouse adds. \u201cWe then compared those reconstructions to a model that uses Einstein\u0027s equations of general relativity, and both reconstructions looked very similar, which helped confirm that this highly unusual phenomenon was a genuine detection.\u201d\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003ESachdev says that seeing the signal at both LIGO Observatories \u2014 placed in Hanford, Washington and Livingston, Louisiana \u2014 was also critical. \u201cThese short signals are very hard to detect, and this signal is so unlike any of the other binary black holes that we\u0027ve seen before,\u201d she says. \u201cWithout both detectors, we would have missed it.\u201d\u003C\/p\u003E\u003Ch3\u003E\u003Cstrong\u003EA Decade of Discovery\u003C\/strong\u003E\u003C\/h3\u003E\u003Cp dir=\u0022ltr\u0022\u003EWhile the team has yet to determine how the original black holes formed, one theory is that they may have resulted from mergers themselves. \u201cThis could have been a chain of mergers,\u201d Sachdev explains. \u201cThis tells us that they could have existed in a very dense environment like a nuclear star cluster or an active galactic nucleus.\u201d Their spins provide another clue as spinning is a characteristic usually seen in black holes resulting from a merge.\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003EThe team adds that GW231123 could provide clues on how larger black holes are formed \u2014 including the mysterious supermassive black holes at the center of galaxies.\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003E\u201cGravitational wave science is almost a decade old, and we\u0027re still making fundamental discoveries,\u201d says Millhouse. \u201cIt\u2019s exciting that LIGO is continuing to detect new phenomena,\u0026nbsp; and this is at the edge of what we\u0027ve seen thus far. There\u0027s still so much we can learn.\u201d\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003EThe team expects to update their catalogue of black holes in August 2025, which will provide another window into how this exceptionally heavy black hole might fit into the universe, and what we can continue to learn from it.\u003C\/p\u003E\u003Cp dir=\u0022ltr\u0022\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003E\u003Cstrong\u003EFunding\u003C\/strong\u003E: The LIGO Laboratory is supported by the U.S. National Science Foundation and operated jointly by Caltech and MIT.\u003C\/em\u003E\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp dir=\u0022ltr\u0022\u003EBefore merging, both black holes were spinning exceptionally fast, and their masses fell into a range that should be very rare \u2014 or impossible.\u0026nbsp;The result of the merge, GW231123, is the largest binary black hole merger ever detected with gravitational waves.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Before merging, both black holes were spinning exceptionally fast, and their masses fell into a range that should be very rare \u2014 or impossible. "}],"uid":"35599","created_gmt":"2025-07-15 02:50:57","changed_gmt":"2025-07-20 23:41:24","author":"sperrin6","boilerplate_text":"","field_publication":"","field_article_url":"","location":"Atlanta, GA","dateline":{"date":"2025-07-15T00:00:00-04:00","iso_date":"2025-07-15T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"677428":{"id":"677428","type":"image","title":"An illustration of the binary black hole merger. (Image credit: Raul Perez and Davis Newell)","body":"\u003Cp\u003EAn illustration of the binary black hole merger. (Image credit: Raul Perez and Davis Newell)\u003C\/p\u003E","created":"1752677703","gmt_created":"2025-07-16 14:55:03","changed":"1752677703","gmt_changed":"2025-07-16 14:55:03","alt":"An illustration of the binary black hole merger. (Image credit: Raul Perez and Davis Newell)","file":{"fid":"261324","name":"blackhole.jpg","image_path":"\/sites\/default\/files\/2025\/07\/16\/blackhole.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2025\/07\/16\/blackhole.jpg","mime":"image\/jpeg","size":817859,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2025\/07\/16\/blackhole.jpg?itok=hDsfUKTq"}}},"media_ids":["677428"],"groups":[{"id":"1278","name":"College of Sciences"},{"id":"1188","name":"Research Horizons"},{"id":"126011","name":"School of Physics"}],"categories":[{"id":"136","name":"Aerospace"},{"id":"150","name":"Physics and Physical Sciences"},{"id":"135","name":"Research"},{"id":"134","name":"Student and Faculty"}],"keywords":[{"id":"192252","name":"cos-planetary"},{"id":"187915","name":"go-researchnews"}],"core_research_areas":[{"id":"193653","name":"Georgia Tech Research Institute"},{"id":"193657","name":"Space Research Initiative"}],"news_room_topics":[{"id":"71881","name":"Science and Technology"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EWritten by Selena Langner\u003C\/p\u003E\u003Cp\u003EContact: \u003Ca href=\u0022mailto: jess.hunt@cos.gatech.edu\u0022\u003EJess Hunt-Ralston\u003C\/a\u003E\u003C\/p\u003E","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}