IIT Hyderabad researchers help discovery behind universe's humming via low-frequency gravitational waves

HYDERABAD: A global team of astronomers from India, Japan, and Europe, lead by researchers from IIT Hyderabad (IITH), has published data from observing pulsars, nature's greatest clocks, with six of the world's most sensitive radio telescopes, including India's largest telescope, uGMRT.

These findings provide evidence for the constant variations of the universe's fabric caused by ultra-low frequency gravitational waves. Such waves are projected to originate from a large number of dancing monster black hole pairs, that are billions of times more massive than our Sun.

The team's findings represent an important milestone towards discovering a new, astrophysically-rich window in the gravitational wave spectrum.

Such dancing monster Black Hole pairs, expected to lurk in the centres of colliding galaxies, create ripples in the fabric of our cosmos, and astronomers call them nano-hertz gravitational waves as their wavelengths can be many lakhs of crores of kilometres. The relentless cacophony of gravitational waves from a large number of supermassive black hole pairs creates a persistent humming of our universe.

The team, which included members of the European Pulsar Timing Array (EPTA) and the Indian Pulsar Timing Array (InPTA) consortia, published their findings in two papers in the journal Astronomy and Astrophysics, and their findings indicate at the presence of such gravitational waves in their data set. These findings include an analysis of pulsar data collected over a 25-year period by six of the world's largest radio telescopes.

Dr. Shantanu Desai, faculty in the Departments of Physics and AI, Aman Srivastava, a Physics PhD student, Divyansh Kharbanda (2023 BTech graduate in Engineering Physics), and Swetha Arumugam (rising BTech senior in EE) were part of the IITH team that made this recent finding. Pragna Mamdipaka, a B Tech student in EE, is also a member of InPTA and actively involved in ongoing InPTA operations. IITH has been a member of InPTA since 2018, and several of its previous InPTA students currently attend advanced degrees in Astrophysics and related fields.

Emphasizing the importance of this result and IITH’s contribution, Prof B S Murty, Director, IITH, said, “Congratulations to the InPTA collaboration and the IITH team involved in this discovery. I am delighted that the state-of-the-art NSM Param Seva computing facility at IITH has helped to create these path-breaking results. This achievement also underscores the power of collaboration in attaining scientific benchmarking results."

“I am elated that IITH students from both Physics and Electrical Engineering could be part of this historical discovery. These results are due to many years of painstaking efforts from many scientists. I am grateful for the support received from IITH. In particular, the results could not have been possible without the NSM (National Supercomputing Mission) facility Param Seva installed at IIT Hyderabad, " said Prof Shantanu Desai, IITH.

The InPTA experiment involves researchers from NCRA (Pune), TIFR (Mumbai), IIT (Roorkee), IISER (Bhopal), IIT (Hyderabad), IMSc (Chennai) and RRI (Bengaluru) along with colleagues from Kumamoto University, Japan.

This combined IPTA data set is expected to be more sensitive, and scientists are excited about the constraints they can place on the (Gravitational Wave Background(GWB) along with understanding various other phenomena that may have taken place when the Universe was in its infancy, just a few seconds old, which can also produce gravitational waves at these astronomically long wavelengths.