IIT Roorkee scientists help discover humming of universe through gravitational waves

The team, consisting of members of the European Pulsar Timing Array (EPTA) and Indian Pulsar Timing Array (InPTA) consortia, published their results in two seminal papers in the Astronomy and Astrophysics journal, and their results hint at the presence of such gravitational waves in their data set. Professor P Arumugam and his senior PhD student, Jaikhomba Singha, are part of these ground-breaking results.

"These results have culminated due to years of efforts of many scientists, including early career researchers and undergraduate students. I am very grateful that IIT Roorkee has been able to constantly contribute in various ways in achieving these results. The NSM facility, PARAM Ganga, installed at IIT Roorkee, among various other facilities, has played a crucial role in this global effort. I hope IIT Roorkee will continue to support the various efforts of this stellar collaboration," states Prof. Arumugam, Department of Physics, IIT Roorkee.

These light-year-scale ripples can only be detected by synthesizing a galactic-scale gravitational-wave detector using pulsars-the only accessible celestial clocks for humans. Pulsars are a type of rapidly rotating neutron stars that are essentially embers of dead stars, present in our galaxy.

Fortunately, a pulsar is a cosmic lighthouse as it emits radio beams that flash by the Earth regularly, just like a lighthouse near a harbour. Astronomers monitor these objects using the best radio telescopes in the world, including India’s premiere radio telescope, the uGMRT, situated near Pune.

According to Albert Einstein, gravitational waves change the arrival times of these radio flashes and thereby affect the measured ticks of our cosmic clocks. These changes are so tiny that astronomers need sensitive telescopes like the uGMRT and a collection of radio pulsars to separate these changes from other disturbances. The slow variation of this signal has meant that it takes decades to look for these elusive nano-hertz gravitational waves.

Singha, a senior PhD scholar from IITR says, "This is an extremely exciting time for early career researchers. We are in an era where an international team of researchers across the globe are all collaborating and trying to listen to the humming of our universe. The present results will open a plethora of exhilarating science for us in future."