Pulsars and Gravitational Wave Astronomy

Pulsars are spinning dead stars that have long since consumed all their nuclear fuel and collapsed into super-dense remnants. Astronomers have discovered over 3,000 of these objects including a remarkable binary pulsar that provided the first experimental evidence for the emission of gravitational waves leading to the 1993 Nobel Prize. Pulses of radiation from the spin can be used as extremely precise clocks with which to measure extreme gravity and test the limits of general relativity.  

Gravitational waves can also be measured directly here on Earth, as they cause space and time to squeeze and stretch as they pass through the world's most precise interferometers. Over 100 years ago, Albert Einstein predicted that these ripples in space-time would be created by accelerating masses and objects orbiting each other. Recent advances in detector sensitivity led to the first direct detection of gravitational waves in 2015.

This was a landmark achievement in human discovery, heralding the birth of the new field of gravitational wave astronomy and receiving the 2017 Nobel Prize in Physics. This was followed in 2017 by the first observations of the collision of two neutron-stars. The accompanying explosion was subsequently seen in follow-up observations by telescopes across the globe and ushered in a new era of multi-messenger astronomy.

The Centre for Astrophysics and Supercomputing (CAS) is home to the headquarters of the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav), which involves over 200 members around Australia and overseas, and is part of the international LIGO-Virgo-Kagra collaboration. Swinburne's Professor Matthew Bailes leads OzGrav and is a pioneer in the discovery of pulsars, having led several pulsar survey and timing arrays, including MeerTIME that uses the power of the new MeerKAT telescope to explore fundamental physics and astrophysics via radio pulsar timing.

Swinburne is also one of the founding members of the Parkes Pulsar Timing Array that regularly times over 20 millisecond pulsars to microsecond precision with the aim of detecting gravitational waves from supermassive black hole binaries in distant galaxies. We also develop models of gravitational wave emission from supernovae and the binaries that produce gravitational wave sources and binary pulsars.  

CAS is also a world leader in the electromagnetic follow-up of gravitational waves and other transient sources, through the Deeper, Wider, Faster program led by Associate Professor Jeff Cooke. We are also home to the GW Data Centre, which is one of the largest dedicated gravitational wave supercomputing groups in the world, led by Professor Jarrod Hurley.