However, modeling has shown that it is It is difficult to scatter enough stars Toward black holes to solve the final-parsec problem.
Alternatively, each black hole may have a small disk of gas surrounding it, and these disks may draw in material from a larger disk that surrounds the empty region created by the hole. “The disks around them are being fed from the massive disk, and that means, in turn, their orbital energy can leak into the massive disk. This is a very effective solution,” said Natarajan. It seems. “There’s plenty of gas available.”
In January, Blecha and his colleagues Tested the idea that a third black hole in the system may provide a solution. In some cases where two black holes have stalled, another galaxy may begin merging with the first two, bringing an additional black hole with it. “You can have a strong three-body interaction,” Blecha said. “This can take away energy and greatly reduce fusion times.” In some scenarios, the lightest of the three holes is ejected, but in others all three merge.
Tests on the horizon
Now the task is to find out which solution is correct, or if multiple processes are running.
Alonso-Alvarez hopes to test his idea by looking for a hint of self-interacting dark matter in the upcoming Pulsar Timing Array data. Once the black holes approach for the final parsec, they release angular momentum, mainly gravitational waves. But if self-interacting dark matter is at play, we should see it siphoning some energy at distances around the parsec range. This in turn would create less energetic gravitational waves, Alonso-Alvarez said.
Hai-Bo YuA particle physicist at the University of California, Riverside who A Proponent of self-interacting dark matterSaid that this idea is plausible. “This is an opportunity to explore subtle properties of dark matter from gravitational wave physics,” he said. “I think it’s just interesting.”
The European Space Agency’s Laser Interferometer Space Antenna (LISA) spacecraft, a gravitational wave observatory set to launch in 2035, We can answer more. LISA will pick up strong gravitational waves emitted by merging supermassive black holes in their final days. “With Lisa we will actually see supermassive black holes meeting,” Pacucci said. The nature of that signal, solving the finite-parsec problem, “represents specific symptoms that indicate a slowing process.”
Original story Reprinted with permission Quanta Magazine, An editorially independent publication of Simons Foundation It aims to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences.
