From its first day of operation in July 2019, the Gravitational Wave Data Centre (GWDC) has been the premier Australian facility for the burgeoning field of gravitational wave science. With data streaming in from observatories around the world, the Centre continues to provide support for Australian researchers – allowing them to take centre stage in the ongoing hunt for new gravitational wave events.
Based at Swinburne University of Technology, the GWDC is the first internationally-recognised gravitational wave data centre in Australia. Created to provide infrastructure, training and support to gravitational wave researchers across the country, the GWDC enables Australian researchers to lead the discovery of events from the latest data on an international scale and to maximise the scientific impact of their discoveries.
This has primarily been achieved via GWDC’s support of existing pipelines, originally created to instantly process and analyse data from gravitational wave observatories located in the United States and Europe. Currently Australia’s only real-time gravitational wave detection pipeline, the Summed Parallel Infinite Impulse Response (SPIIR) pipeline is one of four key software systems located at the gravitational wave observatories in the US, Europe and Japan. Run on computers to detect events in real time, signals are only considered likely gravitational wave detections if identified by more than one pipeline. The SPIIR pipeline is supported, developed and optimised by GWDC staff. Using Swinburne’s OzSTAR supercomputer extensively, researchers (including those from the ARC Centre of Excellence for Gravitational Wave Discovery – OzGrav) have been able to make several remarkable discoveries, including the first detected merger of a neutron star and black hole (announced in mid-2021, and detailed in the AAL 2020/21 Annual Report).
In late 2021 it was announced that the GWDC played a vital role in the detection of 35 new gravitational wave events – a record number over a 5 month period between November 2019 and March 2020.
Gravitational waves are ripples in space-time caused by the acceleration of massive objects. Predicted over 100 years ago, gravitational waves were first detected in 2015. All the detections since then have been caused by the spiral in and collision of black holes and neutron stars.
On 9 November 2021, the international collaboration to detect gravitational waves released its third catalogue of detections. Observational data collected during the “O3” observing run (21 weeks from late 2019 to early 2020) required 18 months of analysis before researchers could understand the nature of the systems behind each event. The catalogue lists 35 new events, bringing the total number of gravitational waves detected since 2015 to 90.
Gravitational wave detection requires instruments capable of some of the most precise and sensitive measurements ever made. Analysis of the measurements then require sophisticated codes run for many months on vast supercomputers. Researchers responded to the scale of the problem by forming a global collaboration based around two detectors in the US (LIGO Hanford and Livingston), one in Europe (Virgo) and one in Japan (KAGRA), and a number of supercomputing centres including the GWDC in Australia.
The GWDC supported the latest international effort in a number of key ways:
The GWDC has provided support that critically enables Australian gravitational-wave researchers to continue their leading role in this exciting new scientific field of discovery.
The GWDC team contributed a 60 minute session at the OzGrav Retreat on November 24th (delivered remotely via GatherTown). The session featured an overview of the GWDC, short updates from the science leaders of the key development projects (SPIIR, MeerTime, GWCloud, GWLab, GWLandscape), an update on the progress of small development projects and time for discussion with the gravitational wave research community.
GWCloud makes it simple to access gravitational wave astronomy data with an intuitive, fully managed job system. During 2021/22, the integration of GWCloud with the CIT cluster at Caltech was a big highlight for the GWDC team, as it expanded the reach of GWCloud and further cemented the role of GWDC within the international LIGO community. The initiation of the GWLandscape project was also a highlight for the GWDC. GWLandscape is a web portal designed to interact with the COMPAS code used by OzGrav to model populations of merging compact objects (COMPAS stands for Compact Object Mergers: Population Astrophysics and Statistics).
AAL were delighted to have been awarded an additional $1.4M from the NCRIS program to support the GWDC and computing projects related to the European Southern Observatory (ESO).
The GWDC is utilising its part of the funding to maintain operations and support the SPIIR pipeline. Designed to detect cosmic gravitational wave signals from coalescing binary neutron stars and black holes in real time, the pipeline will contribute to a globally coordinated all-sky survey set to run from late 2022 until 2024. This will be the longest and most sensitive observing run ever conducted, involving gravitational wave detectors located in the US, Italy and Japan.
For more, see AAL’s news story here.
The GWDC currently supports research from six major Australian institutions – The Australian National University, Monash University, Swinburne University of Technology (host institution for the GWDC), The University of Melbourne, The University of Western Australia and The University of Adelaide. The GWDC operates alongside the existing Astronomy Data and Computing Services (ADACS) team at Swinburne, which has been providing a generalised data and computing service to the national astronomy community from early 2017.