A spectacular cosmic event will occur in the next 10 years. A new research predicts that a collision of two supermassive black holes will generate gravitational waves.
By analyzing the local nanohertz gravitational-wave landscape, researchers were able to forecast that in a 10-year time frame, astronomers will witness the most powerful gravitational waves ever recorded.
In 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) first detected the presence of cosmic ripples after the collision of two black holes. Last month, LIGO also detected gravitational waves from the merging of binary neutron stars, which are smaller than black holes. Supermassive black holes have a mass billions of times than that of the sun. Early collisions observed were from black holes only a dozen times the mass of the sun.
"They absolutely dwarf the black hole mergers detected by LIGO," said lead author Chiara Mingarelli, who is also a research fellow at Flatiron Institute's Center for Computational Astrophysics.
Evolution Of Massive Galaxies
Detecting the merging of two supermassive black holes will provide scientists a deeper understanding of how black holes and galaxies change over time. Scientists believe that when two galaxies collide, it allows supermassive black holes to move to the heart of the newly formed galaxy where they eventually merge. This process is enough to create intense cosmic ripples through the fabric of space and time.
Mingarelli said that the absence of gravitational wave sighting within the decade-long time frame should force scientists to reevaluate the process of how supermassive black holes unite. Known as the Final Parsec Problem, absence of the merger can stall at approximately three light-years of separation. While the black holes will still merge, it may do so at an extended time that energy to produce a detectable gravitational wave is lost.
The current research also identified which galaxies are highly expected to have the supermassive black hole merger. Massive galaxies have larger black holes and stronger gravitational waves, but they also undergo a faster rate of merging, which may reduce the detection window.
Pulsar-Watching Projects
Observing the gravitational waves from this predicted merging of supermassive black holes will influence pulsar stars. Acting like cosmic metronomes, which send out a steady rhythm of radio wave pulses, these stars will change in rhythm in the presence of passing gravitational waves. Pulsar-watching projects on Earth will monitor rhythm changes.
There are currently three projects known as the International Pulsar Timing Array made up of the North American Nanohertz Observatory for Gravitational Waves, Parkes Pulsar Timing Array in Australia, and the European Pulsar Timing Array.
Mingarelli and her team is 100 percent certain that these pulsar-watching observatories will be detected within the 10-year time frame.
The research is published in Nature Astronomy on Nov. 13.
