Research group ASTRON · NL PI · Aditya Parthasarathy

The GIGA group.

The only research group in the Netherlands dedicated to nanohertz gravitational-wave astrophysics, based at ASTRON.

We detect the whispers of supermassive black-hole binaries using pulsars — nature's most precise clocks — observed with the world's largest radio telescopes and with NASA's Fermi gamma-ray satellite. The group is part of the European and International Pulsar Timing Array collaborations, and is hosted jointly between ASTRON in Dwingeloo and the Max Planck Institute for Radio Astronomy in Bonn.

§ 01 / About

A research programme across radio and gamma-ray.

Three interlocking threads: the science of the nanohertz gravitational-wave sky, the instruments that measure it, and the pipelines that make the inference tractable.

In 2023 the European Pulsar Timing Array, together with partner collaborations worldwide, announced the first compelling evidence for a cosmic gravitational-wave background at nanohertz frequencies — a signal most naturally explained by the ensemble of merging supermassive black-hole binaries across the Universe. The GIGA group is part of that effort, and our research pushes toward the next detection: characterising individual sources, sharpening our handle on the pulsar noise that limits us, and opening an entirely independent window on the signal through gamma-ray pulsar timing.

The group is based at ASTRON in Dwingeloo, with a shared presence at the Max Planck Institute for Radio Astronomy in Bonn, and close ties to the University of Amsterdam.

Thread I

Gravitational-wave science

EPTA / IPTA noise modelling, gravitational-wave background characterisation, and multi-messenger follow-up of the nanohertz sky.

Thread II

Instruments

MeerKAT pulsar timing backends, a phased-array feed with Breakthrough Listen, the Gamma-ray PTA on NASA's Fermi, and the Westerbork upgrade.

Thread III

Inference & pipelines

meerpipe, TempoNest, and next-generation Bayesian inference engines that make precision pulsar timing tractable at scale, running on the GIGA cluster at ASTRON.

§ 02 / Team

The people behind the signal.

Principal investigator01

Dr. Aditya Parthasarathy

Staff Scientist · Group PI

Aditya leads the GIGA group at ASTRON. His research focuses on detecting gravitational waves using pulsar timing arrays, precision pulsar timing, and characterising intrinsic noise processes in pulsars. He is a steering committee member of the European and International Pulsar Timing Array collaborations, and co-founder of the Gamma-ray PTA programme using NASA's Fermi satellite. Before joining ASTRON he held a postdoctoral position at MPIfR Bonn, and obtained his PhD from Swinburne University of Technology, Melbourne.

Postdoctoral researchers02