The MeerKAT Pulsar Timing Array

2024 December: The first MPTA GW searches

We are pleased to announce the release of the MPTA 4.5-year dataset, alongside the results of the inaugural gravitational wave searches conducted with the MeerKAT radio telescope. These findings highlight MeerKAT’s exceptional capabilities for pulsar timing array science and underscore the critical role MeerKAT and the Square Kilometre Array (SKA) will play in advancing International Pulsar Timing Array (IPTA) collaborations.

Image credit: Carl Knox, OzGrav, Swinburne University of Technology

We have used the MeerKAT Pulsar Timing Array to create the most detailed maps of gravitational waves across the Universe, providing new insights into the gravitational wave background—a cosmic hum generated by merging supermassive black holes and other energetic events.

This international effort, detailed in three studies published in Monthly Notices of the Royal Astronomical Society, demonstrates the power of MeerKAT, one of the world’s most sensitive radio telescopes, in detecting these elusive signals.

Key Discoveries:

• Unprecedented Gravitational Wave Detection: Our team captured a remarkably strong signal from merging supermassive black holes, surpassing similar experiments in significantly less time.
• Detailed Gravitational Wave Maps: The maps reveal unexpected hotspots, suggesting directional biases in the gravitational wave background that may point to new astrophysical phenomena.

These results challenge previous assumptions about the uniformity of the gravitational wave background and open new avenues for studying the formation of massive black holes, galaxy evolution, and the Universe’s large-scale structure. Future observations with MeerKAT will refine these maps and further unravel the mysteries of the cosmic landscape.

Image credit: Carl Knox, OzGrav, Swinburne University of Technology and South African Radio Astronomy Observatory (SARAO)

The papers can be found here:

1. The MeerKAT Pulsar Timing Array: The 4.5-year data release and the noise and stochastic signals of the millisecond pulsar population
   Matthew T. Miles, Ryan M. Shannon, Daniel J. Reardon,Matthew Bailes, David J. Champion, Marisa Geyer, Pratyasha Gitika, Kathrin Grunthal, Michael J. Keith, Michael Kramer, Atharva D. Kulkarni, Rowina S. Nathan, Aditya Parthasarathy, Nataliya K. Porayko, Jaikhomba Singha, Gilles Theureau, Federico Abbate, SarahBuchner, Andrew D. Cameron, Fernando Camilo, Beatrice E. Moreschi, Golam Shaifullah, Vivek Venkatraman Krishnan Monthly Notices of the Royal Astronomical Society, 2025
2. The MeerKAT Pulsar Timing Array: The first search for gravitational waves with the MeerKAT radio telescope
   Matthew T. Miles, Ryan M. Shannon, Daniel J. Reardon, Matthew Bailes, David J. Champion, Marisa Geyer, Pratyasha Gitika, Kathrin Grunthal, Michael J. Keith, Michael Kramer, Atharva D. Kulkarni, Rowina S. Nathan, Aditya Parthasarathy, Jaikhomba Singha, Gilles Theureau, Eric Thrane, Federico Abbate, Sarah Buchner, Andrew D. Cameron, Fernando Camilo, Beatrice E. Moreschi, Golam Shaifullah, Andrea Possenti, Vivek Venkatraman Krishnan. Monthly Notices of the Royal Astronomical Society, 2025
3. The MeerKAT Pulsar Timing Array: Maps of the gravitational-wave sky with the 4.5 year data release.
   Kathrin Grunthal, Rowina S. Nathan, Eric Thrane, David J. Champion, Matthew T. Miles, Ryan M. Shannon, Atharva D. Kulkarni, Federico Abbate, Sarah Buchner, Andrew D. Cameron, Marisa Geyer, Pratyasha Gitika, Michael J. Keith, Michael Kramer, Paul D. Lasky, Aditya Parthasarathy, Daniel J. Reardon, Jaikhomba Singha, Vivek Venkatraman Krishnan. Monthly Notices of the Royal Astronomical Society, 2024

Matt Miles and Rowina Nathan wrote an article in The Conversation about the findings can be found here