NEWS & PRESS
A telescope located deep in the West Australian outback has shown what the Universe would look like if human eyes could see radio waves.
Published today in the Monthly Notices of the Royal Astronomical Society, the GaLactic and Extragalactic All-sky MWA, or ‘GLEAM’ survey, has produced a catalogue of 300,000 galaxies observed by the Murchison Widefield Array (MWA), a $50 million radio telescope located at a remote site north-east of Geraldton.
Lead author Dr Natasha Hurley-Walker, from Curtin University and the International Centre for Radio Astronomy Research (ICRAR), said this is the first radio survey to image the sky in such amazing technicolour. “The human eye sees by comparing brightness in three different primary colours – red, green and blue,” she said. “GLEAM does rather better than that, viewing the sky in each of 20 primary colours. That's much better than we humans can manage, and it even beats the very best in the animal kingdom, the mantis shrimp, which can see 12 different primary colours.”
GLEAM is a large-scale, high-resolution survey of the radio sky observed at frequencies from 70 to 230 MHz, observing radio waves that have been travelling through space—some for billions of years. “Our team are using this survey to find out what happens when clusters of galaxies collide,” Dr Hurley-Walker said. “We’re also able to see the remnants of explosions from the most ancient stars in our galaxy, and find the first and last gasps of supermassive black holes.”
MWA director Dr Randall Wayth said GLEAM is one of the biggest radio surveys of the sky ever assembled. “The area surveyed is enormous,” he said. “Large sky surveys like this are extremely valuable to scientists and they’re used across many areas of astrophysics, often in ways the original researchers could never have imagined.”
Completing the GLEAM survey with the Murchison Widefield Array is a big step on the path to SKA-low, the low frequency part of the international Square Kilometre Array radio telescope to be built in Australia in the coming years. “It’s a significant achievement for the MWA telescope and the team of researchers that have worked on the GLEAM survey,” Dr Wayth said. “The survey gives us a glimpse of the Universe that SKA-low will be probing once it’s built. By mapping the sky in this way we can help fine-tune the design for the SKA and prepare for even deeper observations into the distant Universe.”
Tel: +61 423 982 018
Dr Robert Massey
Royal Astronomical Society
Tel: +44 (0)20 7734 3307
Dr Natasha Hurley-Walker
Curtin University, ICRAR
Tel: +61 426 192 677
Dr Randall Wayth
Curtin University, ICRAR, CAASTRO
Tel: +61 418 282 359
Images and Captions
The GLEAM view of the centre of the Milky Way, in radio colour. Red indicates the lowest frequencies, green the middle frequencies and blue the highest frequencies. Each dot is a galaxy, with around 300,000 radio galaxies observed as part of the GLEAM survey. Credit: Natasha Hurley-Walker (ICRAR/Curtin) and the GLEAM Team.
High-resolution videos and images are available from www.icrar.org/GLEAM
Original publication, ‘GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey I: A low-frequency extragalactic catalogue’, published in the Monthly Notices of the Royal Astronomical Society onOctober 27th, 2016. Available from http://s3-ap-southeast-2.amazonaws.com/icrar.org/wp-content/uploads/2016/10/18223055/GLEAM-Paper_sml.pdf
Notes for editors
The Murchison Widefield Array (MWA) is a low frequency radio telescope located at the Murchison Radio-astronomy Observatory in Western Australia’s Mid West. The MWA observes radio waves with frequencies between 70 and 320 MHz and was the first of the three Square Kilometre Array (SKA) precursors to be completed. A consortium of 13 partner institutions from four countries (Australia, USA, India and New Zealand) has financed the development, construction, commissioning and operations of the facility. Since commencing operations in mid 2013 the consortium has grown to include new partners from Canada and Japan. Key science for the MWA ranges from the search for redshifted HI signals from the Epoch of Reionisation to wide-field searches for transient and variable objects (including pulsars and Fast Radio Bursts), wide-field Galactic and extra-galactic surveys, and solar and heliospheric science.
The Square Kilometre Array (SKA) project is an international effort to build the world’s largest radio telescope, led by SKA Organisation based at the Jodrell Bank Observatory near Manchester. Co-located primarily in South Africa and Western Australia, the SKA will be a collection of hundreds of thousands of radio antennas with a combined collecting area equivalent to approximately one million square metres, or one square kilometre. The SKA will conduct transformational science to improve our understanding of the Universe and the laws of fundamental physics, monitoring the sky in unprecedented detail and mapping it hundreds of times faster than any current facility.
The International Centre for Radio Astronomy Research (ICRAR) is a joint venture between Curtin University and The University of Western Australia with support and funding from the State Government of Western Australia.
The Royal Astronomical Society (RAS,www.ras.org.uk), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organizes scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 4000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.
The RAS accepts papers for its journals based on the principle of peer review, in which fellow experts on the editorial boards accept the paper as worth considering. The Society issues press releases based on a similar principle, but the organisations and scientists concerned have overall responsibility for their content.