According to a report on the British "Guardian" website on September 27, astronomers have captured direct evidence of the rotation of a black hole for the first time, providing new insights into the most mysterious celestial body in the universe. According to reports, the focus of the observation is the supermassive black hole at the center of the nearby galaxy "Mesier 87", whose shadow was captured by the Event Horizon Telescope. Like many supermassive black holes, Messier 87 launches powerful jets from the poles into interstellar space at nearly the speed of light.
Scientists have predicted that the rotation of black holes powers these cosmic jets, but have never found direct evidence.
Kazuhiro Haneda of the National Astronomical Observatory of Japan, co-author of the study, said: "After successfully taking pictures of a black hole in this galaxy with the Event Horizon Telescope, whether the black hole is rotating has always been the core of scientists' attention. Now the expectation has become certain. This huge black hole is indeed rotating."
"Messier 87" is 55 million light-years away from Earth and has a black hole 6.5 billion times larger than the sun. Outside the black hole, there is an accretion disk composed of gas and dust, rotating around the edge of this cosmic "sinkhole." Some of this matter is destined to fall into the black hole and be lost forever. But a small portion will be ejected from the black hole's poles at speeds exceeding 99.99% of the speed of light.
Theoretical models suggest that this phenomenon occurs due to the rotation of the black hole. Scientists believe that charged particles in the accretion disk generate a strong magnetic field, which pulls the magnetic field along with it as the black hole rotates. This ultimately results in the magnetic field accelerating particles and escaping the black hole in jets, siphoning energy from the black hole's rotation in the process.
The latest research results published in the journal Nature cite the results of observing "Mesier 87" through the global radio telescope network from 2000 to 2022. Observations show that jets that precess around a center point on the edge of the black hole (precession is originally a physics term, refers to a rotating object being affected by external forces that cause its axis of rotation to rotate around a certain center - this newspaper's note) appear repeatedly with an 11-year cycle. This suggests a misalignment between the black hole's spin axis and the accretion disk, causing the jet to wobble like a top.
The authors of the study said: "The discovery of this precession provides clear evidence that the supermassive black hole in the Messier 87 galaxy is indeed rotating, thus enhancing our understanding of the nature of supermassive black holes."
"This is very exciting because it tells us that the black hole only precesses if it has a non-zero rotation," said Ziri Usi, an astrophysicist at University College London. "This is an indirect but very strong proof of rotation."
Yousi also said that the black hole's rotation may in the future provide insights into the cataclysmic events that lead to the formation of supermassive black holes. He said: "The fact that it's spinning and that it's tilting tells you that pretty crazy things have happened in the past. At some point in its history, something drastic happened. It provides tantalizing hints that that might be the case."