Astronomers have confirmed that the Universe is constantly vibrating, creating a so-called “gravitational-wave background.” These oscillations are likely caused by collisions of giant black holes at the centers of galaxies. New data from the MeerKAT Pulsar Timing Array, the largest detector, shows that this background may be more powerful than expected.
Gravitational waves and black holes
Gravitational waves are characteristic deformations of space-time caused by the motion of massive objects. The strongest waves are generated by supermassive black holes, the remnants of dead stars that form after galaxies merge. When two galaxies merge, their black holes begin to orbit around each other, creating powerful but slow gravitational waves.
To study such waves, astronomers use pulsars – dense neutron stars that emit pulses with surprising precision. By measuring the arrival times of these pulsars, scientists can record how gravitational waves stretch or compress the space between Earth and the pulsars.
MeerKAT and new data
MeerKAT is one of the world’s most sensitive radio telescopes, located in South Africa. As part of the project, it has been observing 83 pulsars for more than five years. The data showed patterns related to the gravitational wave background that were stronger than predicted by models. This may indicate more supermassive black holes than expected.
Moreover, the researchers have created the most accurate maps of the gravitational wave distribution. One of the maps has found a hotspot of activity in the Southern Hemisphere, which supports the theory that waves originate from supermassive black holes.
Space prospects
These discoveries could change our understanding of the structure of the Universe. Scientists believe that the gravitational wave background is a kind of “cosmic ocean” of intersecting waves. It could have arisen either from the merger of black holes or from violent processes in the early Universe.
International collaborations, particularly the International Pulsar Timing Array project, will help combine data from different detectors to verify these results. Scientists also hope to find even more definitive evidence about the origin of gravitational waves, revealing new mysteries about our Universe.
The research is published in the journal Monthly Notices of the Royal Astronomical Society.
We previously reported on how gravitational waves indicated the existence of a previously unseen object.
Provided by phys.org
