A team of scientists has discovered that the spin of supermassive black holes can reveal their origins, providing a “cosmic DNA test” for these mysterious objects. The study, published in Physical Review Letters, used data from 69 gravitational wave events detected by LIGO and Virgo to uncover patterns in black hole spins.
According to the theory of general relativity, massive objects warp spacetime, causing ripples that radiate outward at the speed of light – gravitational waves. When two black holes merge, they emit these waves, which carry away angular momentum and cause the binary system to tighten.
The team found that as a black hole reaches a certain mass, its spin changes. This represents a clear mass threshold where the spin pattern corresponds with models suggesting black holes grow through repeat collisions in densely packed star clusters.
By refining computer modeling techniques used to simulate black hole formation and growth, scientists can now better interpret gravitational wave signals detected by future facilities like the Einstein Telescope and LISA. The study provides unprecedented insights into the origins of supermassive black holes, which may have formed in different ways, challenging current understanding.
Source: https://www.space.com/black-hole-size-spin-ancestors