It may be time to rewrite the textbooks!
Back in February, a team of international scientists announced that, using the Laser Interferometer Gravitational Wave Observatory (LIGO), they had finally detected spacetime distortions known as gravitational waves produced from the collision of two smaller-sized black holes roughly 1.3 billion light-years from Earth.
The gravitational wave signal was generated by the rapid spiraling and collision of two black holes, an event that created the famous black hole “chirp.”
This observation not only confirmed one of the last predictions of Einstein’s 100-year-old theory of general relativity, it should also help researchers learn more about the formation of the universe.
And it has already led to some interesting results.
On Monday (April 18), NASA announced that its Fermi Gamma-ray Space Telescope detected faint, tiny bursts of high-energy X-rays, consistent with a short gamma-ray burst (GBR), less than a second after LIGO registered the gravitational waves. The GRB also came from the rough vicinity of the predicted source of the gravitational waves, which is extremely surprising.
It was assumed that when black holes collide, they do so “cleanly,” not producing any kind of electromagnetic trace, according to a NASA news release. So are the two signals related to the same event? The timing makes it highly likely. In fact, there is only a 0.2 percent chance that they occurred in the same patch of sky at the same time but belonged to two different high-energy phenomena.
"This is a tantalizing discovery with a low chance of being a false alarm," said Valerie Connaughton, the lead researcher on the gamma-ray burst project from the National Space, Science and Technology Center in Huntsville, Alabama, in the NASA announcement.
Physicists now have to determine whether or not they fully understand the dynamics of black holes mergers or consider the possibility that they are seeing some new physics that have so far remained hidden.
"But before we can start rewriting the textbooks, we'll need to see more bursts associated with gravitational waves from black hole mergers," said Dr. Connaughton, who is the lead author of the paper currently under review by The Astrophysical Journal.
The latest findings have already generated several papers from scientists explaining how electromagnetic radiation could come from these less massive, merging black holes. One hypothesis, by astrophysicist Avi Loeb of the Harvard-Smithsonian Center for Astrophysics (CfA) in Massachusetts, suggested that the two black holes formed in the belly of a single star.
"There [are] a lot of interesting ideas out there, and it was amazing how quickly those ideas were thrown together," said Judy Racusin, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, in press conference as reported by Space.com.
Nevertheless, this is an exciting time to be an astronomer as gravitational waves continue to reveal insights into some of the most extreme events in the universe, and may also lead to the discovery of new cosmological mysteries.