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UMass Dartmouth professor and students discover fast-moving black hole

Black hole graphic
Graphic courtesy Tia Martineau '18 (B.S. Physics), current PhD candidate studying binary neuron star mergers at the University of New Hampshire

UMass Dartmouth Assistant Professor , Ph.D., and graduate students, Tousif Islam and Feroz H. Shaik, recently partook in a study that found the first evidence of a black hole moving at high-speed, clocked at roughly 3 million miles per hour. This speed is a result of a collision between two black holes.  is the first to provide evidence with actual astronomical data from a black hole merger, named GW200129, providing the first confirmation of theories that trace back to Albert Einstein鈥檚 1915 equations of general relativity.

鈥淏lack holes experience a gravitational pull much like here on Earth. If you want to throw your car keys into outer space, you would need to throw them at least 25,000 miles per hour, the escape velocity of Earth. Anything less than that, Earth鈥檚 gravitational pull will bring your keys back down to the ground,鈥 said Field. 鈥淔or a black hole to escape the gravitational pull of its host star cluster or galaxy, you need even more velocity. This is the first observational evidence of a black hole moving fast enough it could theoretically be ejected from its host star cluster or galaxy, under the right circumstances.鈥

The reason this hadn鈥檛 been observed before is primarily due to the lack of technology available to record such data. Laser Interferometer Gravitational-Wave Observatory (LIGO) machines started observing gravitational waves scattered around our globe in 2015. Since then, the detectors and data analysis tools have been steadily improving.

Field, Islam, Shaik, and some of the same team as this paper are involved in another on-going project that uses a new gravitational wave detection model to analyze additional evidence from data LIGO machines have observed. In this project, the GW200129 signal had interesting properties, which prompted a targeted study into what was going on with this event.

鈥淲e weren鈥檛 setting out to look for this,鈥 said Field. 鈥淭here were about 90 signals we were analyzing and this one led to a brand-new discovery.鈥

Rather than burying a discovery in a longer paper, the team decided to publish this result separately, which is currently undergoing peer review. The larger study and analysis remains on-going, with Islam, Shaik, lead author Vijay Varma of the Max Planck Institute for Gravitational Physics in Potsdam Germany, and other collaborators working to finish writing up the results.

鈥淚鈥檝e been working with Tousif and Feroz for a few years each on different projects, and it鈥檚 safe to say this is the biggest astrophysical discovery any of us have been involved with,鈥 said Field. 鈥淏oth of them share an area of expertise in using codes, programs, and interfacing LIGO鈥檚 data to estimate gravitational wave parameters that helped make this discovery.

鈥淎nalyzing each signal takes upwards of a week on a personal laptop, so their work relied heavily upon computing resources in the  at UMass Dartmouth.鈥

Field is a member of the mathematics department at UMassD, but physics problems, he says, are what he most enjoys applying numerical algorithms to. As a graduate student, he worked to design numerical algorithms to simulate gravitational waves and black holes, igniting his interest in astrophysics.

鈥淎t that time there wasn鈥檛 any data, as LIGO machines weren鈥檛 up and running yet, but there was a lot of interest in developing software, models, and specialized algorithms in anticipation for the data eventually containing gravitational wave signals,鈥 said Field. 鈥淣ow that there鈥檚 more data, there鈥檚 also more opportunities for this effort to have a direct impact on gravitational wave astronomy.鈥

Field's team has created  resembling and explaining the "kick" and "spin" posteriors for GW200129.

UMassD鈥檚 footprint in gravitational wave data 

The 性闻联播 Dartmouth has a strong connection to the study of gravitational wave data. Two of the three founders of LIGO machines (and Nobel Prize winners), , and  have visited UMassD鈥檚 campus to discuss the physics of black holes and gravitational waves over the last six years. 

UMassD Adjunct Professor Gaurav Khanna  last year by finding unique traits that uncovered a loophole in the 鈥渘o hair鈥 theorem, Professor  recently received a  to shed light on the origin of exploding stars, professors  and  have conducted extensive research on aspects of quantum and Yang-Mills gravity, and Collin Capano, whose published numerous papers analyzing alternative theories of gravity that may better describe Einstein鈥檚 theory of general relativity, recently joined UMassD鈥檚 Center for Scientific Computing and Data Science 性闻联播 and is part of the .

鈥淭here鈥檚 a great community of people at UMass Dartmouth and in our region working on different aspects of gravitational science, including: astrophysics, theory, and numerical and computational modeling,鈥 said Field.

鈥淓specially given that we鈥檙e not a huge institution, it鈥檚 impressive to have all these incredible researchers here working on a diverse range of related astrophysics problems. I鈥檓 hoping we can build off of this diverse expertise and grow UMass Dartmouth into an internationally recognized center for research in gravity.鈥 

Black holes experience a gravitational pull much like here on Earth ... This is the first observational evidence of a black hole moving fast enough it could theoretically be ejected from its host star cluster or galaxy, under the right circumstances." Scott Field Ph.D.