The Murchison Widefield Array (MWA) is a significant international research collaboration and astronomy project in outback Western Australia, and for the last decade has been taking science observations for hundreds of astronomers across the globe. The MWA is the official precursor instrument to the future low-frequency SKA project, which will revolutionise our understanding of the Universe and the laws of fundamental physics.
Operated by Curtin University and situated on Wajarri Yamaji country at Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-astronomy Observatory, the MWA telescope contains 4,096 dual-polarisation antennas tuned to receive radio signals from the sky between 70 and 300MHz. Since its launch in 2013, the MWA has collected tens of petabytes of astronomical data which are stored at the Pawsey Supercomputing Research Centre in Perth. From there, the data are accessed and analysed by scientists around the world through the MWA node of the All-Sky Virtual Observatory (MWA-ASVO).
A mysterious new object has been detected with the MWA by a team led by Dr Natasha Hurley-Walker, at the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR).
This object, named GPM J1839−10, has been classed as a ‘magnetar’ – a rare type of star that has extremely strong magnetic fields. These magnetic fields produce powerful bursts of energy and, until now, it was believed all magnetars released this energy every few seconds, or every few minutes. The magnetar detected by the MWA was found to release energy every 22 minutes, making it quite different to every other known magnetar. The magnetar signal was also found within telescope data taken across three decades, meaning it has been releasing energy and slowing down for a very long time, to a point where it should not be able to emit this energy anymore. This result, published in the high-impact scientific journal Nature, questions our understanding of the physics of neutron stars and the behaviour of magnetic fields in extreme environments.
This discovery was made possible through the availability of historical data, highlighting the utility of the extensive MWA archive at the Pawsey Supercomputing Research Centre. Ongoing storage for data collections of national significance, including the Galactic and Extra-Galactic All-Sky MWA (GLEAM) survey, has been provided by the Australian Research Data Commons (ARDC) data retention project.
For more details, please head over to the ICRAR story.
A team led by ICRAR-Curtin researchers have published details on how they are using the MWA radio telescope to survey our Galaxy for rapidly-spinning neutron stars, called pulsars. The Southern-sky MWA Rapid Two-Metre (SMART) survey aims to collect data covering the entire southern sky at long radio wavelengths in search of new pulsars. The team uses the MWA telescope to record data, then performs data checks and quality assurance at the Pawsey Supercomputing Research Centre (where the data are also archived), before searching in earnest on Swinburne’s OzSTAR Supercomputer using processing time awarded by the Astronomy Supercomputing Time Allocation Committee (ASTAC).
From an initial ‘shallow search’, which processed only 10% of the collected SMART survey data, millions of pulsar candidates were identified. Further inspection of only 10% of those candidates has already resulted in the discovery of four pulsars! For more details, please head over to the Space Australia story.
In April 2022, the MWAX correlator was announced as a finalist for the 2022 Engineers Australia Project Excellence Award for its contributions to scientific and technological advances. A technical description paper by Morrison et al. entitled “MWAX: A new correlator for the Murchison Widefield Array”, was featured in the Publications of the Astronomical Society of Australia.
The correlator can be thought of as the ‘brain’ of the MWA radio telescope; it arranges and makes sense of the signals received by the thousands of individual antenna elements within the array, through compute-intensive mathematical operations. A $1 million grant awarded through AAL in late 2020 allowed the purchase of a literal tonne of new computing equipment, which would become the basis of the new MWAX correlator (with the ‘X’ in reference to the cross-correlation function it performs). MWAX was designed to not only replace its aging predecessor, but to improve the MWA’s data systems and support the telescope’s flexibility and future operations.
See this link for the original article about MWA’s new correlator, “Major upgrade to outback telescope a resounding success.”
The MWA was recently awarded $3M in funding through the National Collaborative Research Infrastructure Strategy (NCRIS) to address urgent maintenance requirements and provide an ongoing uplift of MWA operations funding. This new funding will help MWA recover dedicated personnel and address key operational matters for the telescope. The funding will also increase MWA’s resilience and help to secure robust operations through to the end of the facility’s life, ensuring that MWA can continue its role in de-risking the design and operation of SKA-Low until SKA operations commence towards the end of this decade.
Support for the operation of the MWA is provided by the Australian Government via NCRIS, under a contract to Curtin University administered by AAL. Additional funding and in-kind contributions are provided by MWA partner institutions.
With thanks to MWA Project Officer Mia Walker for story contributions.