The Murchison Widefield Array (MWA), a low-frequency (80-300 MHz) radio telescope located at the Murchison Radio-astronomy Observatory in Western Australia, has shown what the Universe would look like if our eyes could see radio waves.
GLEAM view of Milky Way’s center in radio color: red indicates the lowest frequencies, green indicates the middle frequencies and blue the highest frequencies; each dot is a galaxy, with around 300,000 radio galaxies observed as part of the survey. Image credit: Natasha Hurley-Walker / GLEAM Team.
“This is the first radio survey to image the sky in such amazing technicolor,” said Dr. Natasha Hurley-Walker, an astronomer at Curtin University and the International Centre for Radio Astronomy Research (ICRAR).
The survey, called GLEAM (GaLactic and Extragalactic All-sky MWA), has produced a catalogue of 300,000 radio galaxies observed by the MWA telescope.
“The human eye sees by comparing brightness in three different primary colors – red, green and blue,” Dr. Hurley-Walker said.
“GLEAM does rather better than that, viewing the sky in 20 primary colors. 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 colors.”
“Our team is using GLEAM to find out what happens when clusters of galaxies collide,” Dr. Hurley-Walker added.
“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.”
GLEAM is one of the biggest radio surveys of the sky ever assembled.
“The area surveyed is enormous,” said MWA Director Dr. Randall Wayth, also from Curtin University and ICRAR.
“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.”
The results were published online Sept. 16 in the Monthly Notices of the Royal Astronomical Society.
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N. Hurley-Walker et al. GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey I: A low-frequency extragalactic catalogue. MNRAS, published September 16, 2016; doi: 10.1093/mnras/stw2337
