The International Centre for Radio Astronomy Research (ICRAR) has published a new low-frequency radio mosaic of the Milky Way built from thousands of observations by the Murchison Widefield Array. Covering 72–231 MHz and roughly 95% of the galaxy visible from the southern hemisphere, the map uses color to distinguish supernova remnants (orange) from star-forming regions (blue). The mosaic highlights faint, extended features such as near-perfect supernova shells and mysterious odd radio circles (ORCs). Future instruments like SKA-Low will deliver still deeper, higher-resolution views.
Stunning Radio-Light Mosaic Reveals the Milky Way's Hidden Landscape
The International Centre for Radio Astronomy Research (ICRAR) has published a new low-frequency radio mosaic of the Milky Way built from thousands of observations by the Murchison Widefield Array. Covering 72–231 MHz and roughly 95% of the galaxy visible from the southern hemisphere, the map uses color to distinguish supernova remnants (orange) from star-forming regions (blue). The mosaic highlights faint, extended features such as near-perfect supernova shells and mysterious odd radio circles (ORCs). Future instruments like SKA-Low will deliver still deeper, higher-resolution views.
13:11, 02.11.2025Science
ICRAR unveils a sweeping low-frequency radio map of our galaxy
Researchers at the International Centre for Radio Astronomy Research (ICRAR) have released an extraordinary low-frequency radio mosaic of the Milky Way that reveals structures invisible to optical telescopes. The mosaic was created by carefully stitching together thousands of observations collected over an eighteen-month campaign with the Murchison Widefield Array (MWA) in Western Australia.
How the image was made
The final map combines data from two wide surveys: GLEAM (completed in 2015) and the deeper follow-up GLEAM-X (taken about three years later). To merge the many individual observations into a coherent whole, the team used a technique called image-domain gridding and applied corrections for ionospheric distortions — small shifts in radio-wave positions caused by irregularities in Earth's upper atmosphere.
Silvia Mantovanini, an ICRAR researcher at Curtin University and lead author of the accompanying paper in the Publications of the Astronomical Society of Australia, said the result 'offers an unmatched view of the galaxy at low radio frequencies.'
What the map shows
The mosaic spans radio frequencies from 72 MHz to 231 MHz and covers roughly 95% of the Milky Way visible from the southern hemisphere. Color coding makes different features easy to distinguish: supernova remnants appear orange, while star-forming regions (stellar nurseries) glow blue. The image highlights nearly circular supernova shells and mysterious, galaxy-sized odd radio circles (ORCs) whose origins remain unclear.
Why it matters
The map is a striking example of the low-surface-brightness universe now being exposed by modern radio telescopes. It provides new insights into stellar life cycles — where stars form, how they interact with the surrounding interstellar medium, and how they die — and it expands the census of faint, extended structures that were previously hidden.
Looking ahead
Even deeper and higher-resolution views are expected in the coming decade when the SKA Observatory's SKA-Low telescope is completed on Wajarri Yamaji Country in Western Australia. SKA-Low will surpass current surveys in sensitivity and resolution, opening an even broader window onto the radio universe.
Technical note: The Murchison Widefield Array comprises more than 4,000 individual antennas spread across almost three square miles, and the GLEAM / GLEAM-X data set represents one of the most comprehensive low-frequency views of the southern sky to date.