The background is too faint to be observed with our current gravitational wave observatories, as these gravitational waves are light-year scale.

Combining three data sets from The European Pulsar Timing Array (EPTA), the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), and the Parkes Pulsar Timing Array in Australia (PPTA), the second data release of the International Pulsar Timing Array (IPTA) was published.

Thanks to data from radio observatory MeerKAT and from the Indian Pulsar Timing Array (InPTA), which just joined IPTA, the data sets will grow and the researchers are confident that they will be able to prove that this is the gravitational wave background.

“The first hint of a gravitational wave background would be a signal like that seen in the IPTA DR2.

Then, with more data, the signal will become more significant and will show spatial correlations, at which point we will know it is a gravitational wave background.

We are very much looking forward to contributing several years of new data to the IPTA for the first time, to help achieve a gravitational wave background detection,” explained Dr Bhal Chandra Joshi, a member of the InPTA.