The Centre for Gravitational Physics hosts the ANU node of
The Centre for Gravitational Physics (CGP) is rebranded to ANU Centre for Gravitational Astrophysics (CGA). For more up-to-date information on our research activities, please visit our CGA website at https://cga.anu.edu.au/.
CGP was founded to undertake research and development for instrumentation for the detection of gravitational waves. These technologies use laser interferometers to sense tiny displacements. We developed and installed instrumentation and control systems in the Laser Interferometer Gravitational wave Observatory (LIGO) and in the GRACE Follow-On mission. We also spun-off gravitational wave detection technologies into a number of related research fields.
Most of the research at CGP was directed towards gravitational wave detection, the related area of high precision measurement, and the exploitation of gravitational waves for astronomy. Our specific research interests include advanced interferometer configurations and control systems, measurement of thermal and quantum noise, quantum noise cancellation and quantum-non-demolition techniques, data analysis, digital interferometry, Gravity Recovery and Climate Experiment (GRACE) Follow-On Mission, and frequency stabilisation for the Laser Interferometer Space Antenna (eLISA).
At the beginning of 2020, we established the Centre for Gravitational Astrophysics (CGA) which is a joint research facility of the ANU Research School of Physics and ANU Research School of Astronomy and Astrophysics. CGA has five main research themes:
- Gravitational Wave Detection
- Gravitational Wave Theory and Data Analysis
- Gravitational Wave Electromagnetic Follow-up
- Space Technology
- Applied Metrology
CGA hosts ANU nodes of two ARC Centres of Excellence:
Detection of the second ever Neutron Star Merger announced
A new collaborative study with the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) reveals a possible collision of two neutron stars earlier in 2019—only the second time this type of cosmic event had ever been detected. The gravitational-wave observatory network, that includes the National Science Foundation's LIGO and the European Virgo detectors, picked up what appeared to be gravitational ripples from a collision of two neutron stars back on 25 April 2019. This second event in 2019, called GW190425, did not result in any light being detected; however, researchers have learned that the collision resulted in a merged object with an unusually high mass, 3.4 times heavier than the Sun. This detection was only possible by continued improvement of the sensitivity of the gravitational wave detectors including reducing the quantum noise in the detectors, in which CGA researchers played a vital role.
Establishment of ANU Centre for Gravitational Wave Astrophysics (CGA)
As of Jan 1st, 2020, CGP is rebranded to ANU Centre for Gravitational Astrophysics (CGA). The Centre is established jointly under RSPhys and RSAA and aims to advance the science and technology of gravitational wave astrophysics and to build a world-leading role for ANU in this field.
The CGA which is led by Professor David McClelland, is located in building 38 and 38B.
A quantum leap that’s been decades in the making - the method of 'Squeezing'
Exciting results are announced on the Centre for Gravitational Physics' role in improving the sensitivity of the LIGO detectors. The results of implementing 'squeezing' in the LIGO detectors are published in the prestigious journal of Physical Review Letters
Cosmic Explorer South, a 40-kilometre long, $1.5 billion instrument to detect Gravitational Waves
CGP is participating in an effort to design the largest gravitational wave detector ever built. This detector that is nicknames Cosmic Explorer South, will be L-shape with 40-kilometre long arms and is a node of a global network of GW detectors around the world along with the Einstein Telescope in Europe and Cosmic Explorer in the US. Cosmic Explorer South would allow scientists to triangulate the source of any waves detected.
The method of Squeezing, more precise detection of collisions of stellar-mass black holes in the Universe
The 'quantum squeezers' designed at ANU along with other upgrades for the current LIGO detectors have already greatly improved the detectors’ sensing capabilities in the third detection run that resumed in April 2019.
CGP’s newest publication ‘Broadband reduction of quantum radiation pressure noise via squeezed light injection’ elaborates on the method of ‘Squeezing’. Published in Nature Photonics in Oct 2019, this method dampens quantum noise and makes measurements more precise, critical for next-generation detectors, which are expected to come online within the next 20 years.
National Science Week 2019 - SciVR
ANU Centre for Gravitational Physics in collaboration with ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) and ACT National Science Week held a live stream event for public on Saturday 17th August at Menzies Library, ANU.
This event was live streamed from Melbourne by Dr Allan Duffy and Dr Rebecca Allen two well known scientists in the field of gravitational wave astrophysics. Allan and Rebecca had an interactive talk using a smart phone application SciVR (Science in Virtual Reality) that let the users explore the invisible universe on their smart phones using a pair of 3D googles. The attendees learnt about the solar system and beyond, black holes, neutron stars as well as gravitational waves and LIGO detectors.
The event was supported by a Seed Grant from ACT National Science Week Committee and was free to public ageing 10 and above.
First detection of a black hole swallowing a neutron star
On August 14 Gravitational Wave community including ANU Centre for Gravitational Physics announced detection of collision of two massive objects about 900 million light years away. The signal was detected by both the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) in the US and the Virgo detector in Italy. It is very likely that the event was a black hole eating up a neutron star. If confirmed, it is the first ever detection of such event.
The scientists had already detected collision of black holes as well as neutron stars, and the recent detection of collision of a black hole and a neutron star completed the GW community's trifecta of observations on their original wish list.
Prof. David McClalland elected Fellow of Australian Academy of Science
Congratulations to Professor David McClelland for being elected Fellow of the Australian Academy of Science for his career achievements in the detection of Gravitational Waves.
The Academy honoured the leader of CGP for his vital contribution to the detection of gravitational waves in 2016 as Australia’s leading audio-band gravitational wave scientist and Chair of the Instrument Science/Advanced Detector program in the 1000-strong LIGO Scientific Collaboration. David played a crucial role in designing, installing and commissioning Advanced LIGO’s acquisition system, and implementing quantum squeezing that improved gravitational wave detection sensitivity.
Opportunity to join an exciting international education project for PhD or Masters by Research or as a Research Associate
We are seeking PhD and Masters students and candidates for Research Associate positions with interest in science communication, outreach and education. In joining this project, as part of the Einstein-First project lead by UWA and ANU, you will be helping to create a revolutionary new school curriculum that will be consistent with our modern understanding of the universe, and the modern technologies that have revolutionized our lives.
Research will be taking place in Perth and Canberra and at linked schools. Postgrad positions can be supported at UWA, Curtin and ANU.
Ancient star-crash detection ushers new dawn for space discovery
An international team of scientists, including from RSPE's Centre for Gravitational Physics, have detected two stars colliding in space about 500 million years ago. The discovery comes just weeks after the restarting of the most sensitive scientific instrument ever built – the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) – which comprises twin detectors in the United States. This is the first time such an event has been witnessed since the detectors were taken offline for upgrades to improve their range and precision, and promises a new dawn for space discovery. On 25 April 2019, one of the LIGO machines detected the ripples in space and time from the collision of two neutron stars, which are the densest stars in the Universe – they have an average radius of 15 kilometres and are twice the mass of our Sun. The neutron star collision occurred about 4,750 million trillion kilometres away from Earth – a distance which equates to 500 million light years.
The Hunt for Gravitational Waves Resumes
LIGO and VIRGO are set to resume their hunt for gravitational waves - ripples in space and time - on April 1. One of the key features of this round of search, which is also called O3, is employment of a technique called "squeezing” to reduce levels of quantum noise that can mask faint gravitational-wave signals. This technique was developed at ANU's Centre for Gravitational Physics, lead by Prof. David McClelland. As the result of the latest upgrades, the LIGO detectors are now about 40% more sensitive compared with the last two rounds of search, which means that they can survey an even larger volume of space for powerful, wave-making events, such as the collisions of black holes. Joining the search will be Virgo, the gravitational-wave detector located at the European Gravitational Observatory (EGO) in Italy, which has almost doubled its sensitivity since its last run and is also starting up April 1. So far LIGO and Virgo have seen ten binary black holes and one binary neutron star. In O3, the researchers are hoping to detect gravitational wave signals from new types of events such as binaries containing both a neutron star and a black hole or continuous gravitational waves from rotating neutron stars.
ARC Linkage Grant Awarded to Test and Review the Success of Teaching Einstein’s Theories
Prof. Susan Scott is among the leaders of a group of Gravitational Wave researchers who are granted $898,560 ARC Linkage funding, announced by the Minister for Education Dan Tehan on March 19th. This project aims to explore teaching the modern Einsteinian paradigm of space, time, matter, light and gravity to students as young as 8 years old. The Einstein First project will focus on testing and evaluating a seamless progression of learning modern physics through primary and secondary school developed through a 7-nation collaboration, with view to worldwide introduction of Einsteinian science at school. The research will be led by Chief Investigator Emeritus Professor David Blair (UWA), Professor Susan Scott (ANU) and collaborators.
Biggest Known Black Hole Collision detected
CGP physicists in RSPE have celebrated the announcement by LIGO & Virgo & OzGrav (ARC Centre of Excellence) of 4 new binary black hole collisions including the biggest, fastest spinning and furthest merger ever recorded. All four newly confirmed black hole coalescences were found in the archived data from the observing run in 2017, coming to light as a result of further data cleaning and recalibration and refinement of the searches. A description of these detections has been released as part of the catalogue of detections by the Advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO) in the US and the Advanced Virgo facility in Italy. The newly announced detections bring the total number of black hole mergers detected to 10 – plus a single binary neutron star merger – over the past three years.
Grace Follow-on satellites with ANU laser technology launched into space
The GRACE Follow-On mission, the successor to the Gravity Recovery and Climate Experiment (GRACE) mission, launched into space from Vandenberg Airforce Base in California aboard a Falcon 9 rocket at 5.47am 23 May 2018. Prof Daniel shaddock’s team from ANU Centre for Gravitational Physics have played a significant role in designing new satellites that are part of a joint NASA and German Space Agency mission launched into space to study changes in water levels on Earth and other aspects of climate change. Using the technology of Laser Ranging Interferometry, Grace follow-on can pick up changes in the separation of the spacecraft by ten nanometres, about the diameter of a virus.
The 2018 Quantum Communication Awarded to the Leader of CGP
Prof David McClelland received the International Organisation for Quantum Communication, Measurement and Computing Award for Outstanding Achievements in Quantum Experimentation. In bestowing McClelland with this award, the organisation cited his “pioneering experimental work and leadership in the development of squeezed vacuum light sources in the audio-band and its successful application to the gravitational wave detector interferometers GEO and LIGO.” The award was shared in equal parts with OzGrav Partner Investigator Prof Nergis Mavalvala (MIT) and Prof Roman Schnabel (Hamburg).
Walter Boas Medal Awarded to the Leader of CGP
Professor David McClelland has been awarded the prestigious Boas medal, by the Australian Institute of Physics, "for key contributions to one of the greatest achievements in the history of physics – the observation of gravitational waves by the Laser Interferometer Gravitational-wave Observatory (LIGO).
Gravitational waves detected for first time from two stars colliding
Scientists from The Australian National University (ANU) and around the world have detected for the first time ripples in space and time, known as gravitational waves, from the collision of two very dense stars, called neutron stars, about 130 million light years away.
Third gravitational wave detection offers new insight into black holes
We detected a third binary black hole merger with the LIGO gravitational wave detectors. The black holes merged about 3 billion years ago and travelled through earth on 4 January 2017. The detection is published in Physical Review Letters, a science summary can be found on the LIGO website. Members of the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) are part of the LIGO Scientific Collaboration.
ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav)
The CGP is the ANU node of the recently awarded ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav). The Centre brings together the Australian gravitational wave community from pulsar-timing to the terrestrial and space based interferometer detectors. OzGrav is a partnership between Swinburne University (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.
Again! Second set of merging black holes found
A second binary black hole merger has been found by LIGO, cementing the new field of gravitational wave astronomy. The paper describing the discovery is published in Physical Review Letters and a science summary can be found on the LIGO website.
We did it! Gravitational waves detected
The LIGO Scientific Collaboration has successfully detected gravitational waves from a pair of colliding black holes
For enquires about the group and our research please contact the head of the group, Professor David McClelland.
Phone: +61 (0)2 6125 2747 (Secretary)
Fax: +61 (0)2 6125 0741