The recent announcement of a 2017 Nobel Prize for the detection of gravitational waves had a Charles Sturt University (CSU) connection, with an academic involved in the research since 2000.

The academic, Dr Philip Charlton, a senior lecturer in mathematics at CSU's School of Computing and Mathematics is a member of the LIGO Scientific Collaboration team who analyses data created by the Laser Interferometer Gravitational-Wave Observatory (LIGO).

Joining the LIGO team in 2000, Dr Charlton's work has included the LIGO data analysis system, characterisation and calibration of the detectors, and detection methods for burst signals and stochastic background signals.

First predicted by Albert Einstein, gravitational waves open up a new way to view the universe and allow observers to view the most violent events in space. Dr Charlton said LIGO first detected gravitational waves in September 2015 and subsequently four more times.

Dr Charlton said that the detections not only confirmed Einstein's general relativity theory was right, but also proved that the LIGO could be used to observe in a more complete way.

"LIGO is capable of utilising the gravitational wave spectrum to observe astrophysical events that would otherwise be inaccessible. It represents the dawn of gravitational-wave astronomy," Dr Charlton said. 

Dr Charlton said the most recent detection in August 2017 was the most spectacular yet.

"LIGO detected the merger of a pair of neutron stars. Unlike black hole mergers which are optically  'silent', the neutron star merger emitted a colossal burst of electromagnetic waves which was detected by optical astronomers just 1.7 seconds after the LIGO detection," Dr Charlton said.

This is the first time that a gravitational wave event has been able to be associated with an optical counterpart.

It has already lead to significant advances in our understanding of astrophysical processes by confirming that neutron star mergers are one of the origins of short gamma-ray bursts and produce some of the heavy elements in the universe, and that the speed of gravitational waves is the same as the speed of light to extremely high accuracy.

In recognition of this discovery, two of the original founders of LIGO, Kip Thorne and Rai Weiss, along with former LIGO Principal Investigator Barry Barish, were awarded the 2017 Nobel Prize in Physics on Tuesday 3 October. Co-founder Ron Drever also celebrated the first successful detection but died in March 2017.

Dr Charlton continues his work with LIGO Scientific Collaboration team, sitting within the stochastic background group.

"This is one of four major divisions within the collaboration, the others being the inspiral group which looks for black hole and neutron star mergers, the burst group which looks for supernovae and other short-term sources, and the continuous waves group that looks for signals from spinning neutron stars," Dr Charlton said. 

"The stochastic background refers to the constant background noise of gravitational waves that is believed to arise from a multitude of unresolved sources, such as relic gravitational waves from the early universe, compact binary systems, and supernovae," Dr Charlton said.  

General information:

LIGO is funded by the NSF, and operated by Caltech and MIT, which conceived of LIGO and led the Initial and Advanced LIGO projects. Financial support for the Advanced LIGO project was led by the NSF with Germany (Max Planck Society), the UK (Science and Technology Facilities Council) and Australia (Australian Research Council) making significant commitments and contributions to the project. More than 1 200 scientists and some 100 institutions from around the world participate in the effort through the LIGO Scientific Collaboration, which includes the GEO Collaboration and the Australian collaboration OzGrav. Additional partners are listed at http://ligo.org/partners.php.

The Virgo collaboration consists of more than 280 physicists and engineers belonging to 20 different European research groups: six from Centre National de la Recherche Scientifique (CNRS) in France; eight from the Istituto Nazionale di  Fisica  Nucleare  (INFN) in Italy;  two in the Netherlands with  Nikhef; the MTA Wigner RCP in Hungary; the POLGRAW group in Poland; Spain with the University of Valencia; and the European Gravitational Observatory, EGO, the laboratory hosting the Virgo detector near Pisa in Italy, funded by CNRS, INFN, and Nikhef.

The ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) is funded by the Australian Government through the Australian Research Council Centres of Excellence funding scheme.  OzGrav is a partnership between Swinburne University of Technology (host of OzGrav headquarters), the Australian National University, Monash University, University of Adelaide, University of Melbourne, and University of Western Australia, along with other collaborating organisations in Australia and overseas. 

The ARC of Excellence for All-sky Astrophysics (CAASTRO) is a collaboration of The University of Sydney, The Australian National University, The University of Melbourne, Swinburne University of Technology, The University of Queensland, The University of Western Australia and Curtin University, funded under the ARC Centre of Excellence program, with additional funding from the seven participating universities and from the NSW State Government's Science Leveraging Fund. The Australia Telescope Compact Array is part of the Australia Telescope National Facility which is funded by the Australian Government for operation as a National Facility managed by CSIRO.