Gravitational waves caused by mega black hole collisions have been discovered, confirming Einstein’s theory of general relativity. In a study published this week in the journal Physical Review Letters, scientists discovered evidence of supermassive black hole collisions hidden in data collected by the LIGO and Virgo detectors in 2019. The largest black hole merger ever recorded produced a black hole 150 times more massive than the Sun, challenging some conventional wisdom.
Physicist Badri Krishnan, one of the study’s authors, said he had considered such an analysis as a theoretical possibility before, but was unsure if he would see such results in his own life. He said he didn’t think so. The merger, registered on May 21, 2019 under the name GW190521, stood out among dozens of similar events. Its merging rate was so low that the system entered the sensitivity range of LIGO and Virgo only during its two later orbits.
Krishnan and his colleagues decided to find out whether the gravitational waves from this event contained information not only about the period before the merger, but also about the moments immediately after the merger. When two black holes merge, they form an asymmetric black hole that quickly becomes spherical. Just as a bell tolls at a specific frequency depending on its shape, a stabilized black hole “collapses” by emitting gravitational waves at a frequency determined by its mass and spin.
Researchers analyzed data from the GW190521 phenomenon and found two different decay frequencies. Taken together, the results suggest that the resulting black hole has a mass about 250 solar masses, much larger than the LIGO-Virgo team’s original analysis estimated.
These discoveries represent a new and rigorous test of Albert Einstein’s theory of general relativity and provide detailed predictions about black holes and gravitational waves. As theoretical physicist Stephen Giddings of the University of California, Santa Barbara, pointed out, we are indeed exploring new frontiers of knowledge.