(Nanowork News) A team of physicists has developed a method to detect gravitational waves at frequencies low enough to reveal secrets behind the early stages of mergers between supermassive black holes, the most massive objects in the universe.
This method can detect gravitational waves that oscillate once every 1,000 years, 100 times slower than previously measured gravitational waves.
“This could affect the way light travels as a wave that reaches us from the furthest reaches of the universe,” said Jeff Dror, Ph.D., assistant professor of physics at the University of Florida and co-author of the new study. “Studying these waves of the early universe will help us build a complete picture of the history of our universe, similar to previous discoveries about the cosmic microwave background.”
Dror and his co-author, William DeRocco, a postdoctoral fellow at the University of California, Santa Cruz, reported their findings: actual review letter (“Detection of subnanohertz gravitational waves using pulsar parameter drift”).
Gravitational waves are similar to cosmic ripples. Like sound waves or ocean waves, gravitational waves vary in frequency and amplitude, information that provides insight into their origin and age. Gravitational waves that reach us can oscillate at very low frequencies, much lower than sound waves that can be detected by the human ear. Some of the lowest frequencies detected in the past were as low as 1 nanohertz.
“For reference, the frequency of the sound waves produced by a crocodile’s roar is about 100 billion times higher than this frequency. These are very low sound waves,” Dror explained.
Their new detection method is based on the analysis of pulsars, which are neutron stars that emit radio waves at very regular intervals. Dror hypothesized that searching for the gradual slowing of the arrival of these pulses could reveal new gravitational waves. By studying existing pulsar data, Dror was able to search for gravitational waves at lower frequencies than ever before, extending the “auditory range” to frequencies as low as 10 picohertz, 100 times lower than previous efforts that detected nanohertz-level waves. There was.
Gravitational waves, with frequencies around nanohertz, have been detected before, but not much is known about their origin. There are two theories. The main idea is that these waves are the result of a merger between two supermassive black holes. If true, it would give researchers a new way to study the behavior of this massive object at the center of every galaxy.
Another major theory is that these waves were created by some kind of cataclysmic event early in the history of the universe. By studying lower frequency gravitational waves, they may be able to distinguish between these possibilities.
“The next step is to analyze new data sets,” Dror said. “The data sets we used were mainly from 2014 and 2015, and numerous pulsar observations have been performed since then.”
Dror also plans to run simulations on simulated data using the University of Florida's HiPerGator supercomputer to further uncover the history of the universe. Supercomputers can run large, complex simulations efficiently, significantly reducing the time needed to analyze data.