Black Hole Mergers Help Astrophysicists Better Understand Gravitational Waves
Black hole mergers could help astrophysicists better understand the mystery of gravitational waves, an idea first postulated by famed physicist Albert Einstein.
University of Cambridge researchers have now found new solutions to equations governing the interaction of two black holes in a binary system as they close in toward each other during a collision. When a pair of orbiting black holes that are rotating collide, merging into a single massive body, the event can be the most energetic in the universe and they release energy in the form of gravity waves.
Gravitational waves are believed to act like ripples on a still pond, except the waves in this case are within spacetime itself. Physicists have long tried to detect this effect using sensitive detectors but have been unsuccessful thus far. As black holes orbit each other, the release of these waves drains energy from the system, drawing the bodies closer together over time.
"An accelerating charge, like an electron, produces electromagnetic radiation, including visible light waves. Similarly, any time you have an accelerating mass, you can produce gravitational waves," said Michael Kesden from the University of Texas at Dallas.
As the black holes collide, they release vast amounts of energy in the form of gravity waves, which may be possible to detect, researchers theorize. Astronomers study objects in space over a wide range of frequencies of the electromagnetic spectrum, including visible and infrared light, radio waves and microwaves. Each form of astronomy provides different information about the body being examined. Once astronomers learn how to observe celestial objects in gravitational waves, the practice could open up a new world of astronomy.
"Using gravitational waves as an observational tool, you could learn about the characteristics of the black holes that were emitting those waves billions of years ago, information such as their masses and mass ratios, and the way they formed. That's important data for more fully understanding the evolution and nature of the universe," Davide Gerosa of Cambridge University stated in a press release.
Equations solved by the team involve the changes of the black holes as they rotate. This action can be compared to the off-center tilt of a child's top as it spins on the floor. Researchers determined, for the first time, that these bodies undergo three distinct phases over time. Understanding how this movement changes over time is crucial to learning more about black holes' evolution.
"With these solutions, we can create computer simulations that follow black hole evolution over billions of years. A simulation that previously would have taken years can now be done in seconds. But it's not just faster. There are things that we can learn from these simulations that we just couldn't learn any other way." Kesden stated in a university press release.
Analysis of the ability to carry out gravitational wave astronomy by studying the collisions of rotating black holes was published in the journal Physical Review Letters.