The new image shows the Milky Way’s heart beating in dazzling radio colours

Image: Silvia Mantovanini/International Centre for Radio Astronomy Research (ICRAR)

Astronomers have released the largest low-frequency radio colour image of the Milky Way, providing a breathtaking new perspective on our galaxy from the Southern Hemisphere. Created by researchers from the International Centre of Radio Astronomy Research (ICRAR), the image provides scientists with a fresh view of how stars are born, evolve and die.

How was the massive Milky Way image created?
The image was constructed by Silvia Mantovanini, a Ph.D. student at Curtin University’s ICRAR node, who spent 18 months and over 40,000 hours on the project. She used supercomputers at the Pawsey Supercomputing Research Centre to process data from two major surveys—the GaLactic and Extragalactic All-sky MWA (GLEAM) and the GLEAM eXtended (GLEAM-X). Both surveys were carried out using the Murchison Widefield Array (MWA) telescope located at Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-Astronomy Observatory on Wajarri Yamaji Country in Western Australia.

What makes this image different from the previous ones?
This new version doubles the resolution, offers ten times more sensitivity and covers twice the area compared with the earlier GLEAM image released in 2019. The results are published in the Publications of the Astronomical Society of Australia. Mantovanini said the colourful image provides an unmatched view of the galaxy at low radio frequencies, helping scientists trace how stars form, interact and end their life cycles. Her research focuses on supernova remnants—vast clouds of gas and energy left after stars explode.

A new radio image shows the Milky Way’s centre as captured by the Murchison Widefield Array, with orange representing low frequencies, green for mid-range, and blue for high frequencies. (Image: Silvia Mantovanini (ICRAR/Curtin) & the GLEAM-X Team)

What new details can astronomers see?

The picture enables scientists to distinguish areas of gas surrounding newborn stars from those that were created by deceased ones. Mantovanini described the large red circles as indicating the remnants of burst stars and the blue smudges of a smaller size as corresponding to stellar nurseries where stars are born. From this information, astronomers hope to locate thousands of previously unknown supernova remnants throughout the Milky Way.

How might it assist in the study of pulsars and galactic structure?
The team also wants to learn more about pulsars — rapidly rotating, highly magnetised neutron stars that produce beams of radio waves. The way pulsars glow at GLEAM-X frequencies helps scientists identify their locations and how these enigmatic objects produce radiation. The principal investigator of GLEAM-X and Associate Professor Natasha Hurley-Walker said that the image shows large-scale structure, which cannot be easily observed at high frequencies.

Associate Professor Natasha Hurley-Walker, the principal investigator of GLEAM-X, said the image reveals large-scale structures that cannot be easily seen at higher frequencies.

What does this mean for future astronomy?
According to Hurley-Walker, this is the first complete low-frequency radio image of the Southern Galactic Plane ever published. She added that only the upcoming SKA Observatory’s SKA-Low telescope, to be built on Wajarri Yamaji Country in Western Australia, will eventually surpass this image in resolution and sensitivity.

ICRAR researchers catalogued 98,000 radio sources visible from the southern hemisphere using the MWA telescope. These include pulsars, planetary nebulae, compact HII regions—clouds of dense ionized gas—and distant galaxies beyond the Milky Way. The image now stands as a detailed radio portrait of our galaxy, helping scientists see its structure in a way never possible before.