Astronomers have unveiled a vast and detailed new radio-color image of the Milky Way, offering a fresh perspective on the large-scale structures that shape our galaxy. Constructed by researchers at the International Centre of Radio Astronomy Research (ICRAR) in Australia, the panorama maps different radio frequencies to colors, revealing astrophysical phenomena like supernova remnants and tracing the lifecycle of stars in unprecedented detail. This work is part of the GLEAM-X survey and provides a comprehensive view of the southern galactic plane at low radio frequencies, a milestone for astronomical imaging.
The new image provides a powerful tool for studying regions of the galaxy that are otherwise obscured by dense concentrations of dust and stars. By using low-frequency radio waves, the survey penetrates this cosmic veil, allowing scientists to map out large structures that are difficult or impossible to see with other telescopes. It complements recent high-energy and infrared images from other major observatories, contributing to a more complete and multi-wavelength understanding of the chaotic and energetic heart of the Milky Way. This combined view is helping to answer long-standing questions about star formation, magnetic fields, and the galaxy’s overall structure.
A New Radio Rainbow
The stunning image is the result of the GLEAM-X survey, which stands for the GaLactic and Extragalactic All-sky MWA eXtended survey. It builds upon a previous survey released in 2019 but boasts twice the resolution and ten times the sensitivity. This enhanced capability allows for a much deeper and clearer view of the galactic plane. The image was painstakingly constructed from data gathered by the Murchison Widefield Array (MWA), a radio telescope in Western Australia. To create the final product, the team combined tens of thousands of individual snapshots, requiring more than 40,000 hours of processing time.
In this visualization, different radio frequencies are assigned to the red, green, and blue channels of the image. This technique allows astronomers to differentiate between various cosmic phenomena based on their radio signatures. For example, the remnants of exploded stars, known as supernovas, are particularly visible in this new map. These remnants are crucial for understanding how heavy elements are distributed throughout the galaxy, seeding the next generation of stars and planets. According to the research team, the image is the largest-ever radio color image of the Milky Way and the first time the entire Southern Galactic Plane has been published in this manner.
Weaving a Magnetic Tapestry
The GLEAM-X survey is not the only recent effort to map our galaxy’s core. A different panorama, created by combining data from NASA’s Chandra X-ray Observatory and the MeerKAT radio telescope in South Africa, reveals a tapestry of energy woven from threads of superheated gas and powerful magnetic fields. This composite image stitches together 370 separate observations from Chandra to create a giant mosaic of the galactic center. It expands the high-energy view farther above and below the galactic plane—the disk where most stars reside—than any previous imaging campaign.
This combined X-ray and radio view has brought enormous, previously unseen structures to light. The data reveals large plumes of hot gas extending approximately 700 light-years above and below the plane of the galaxy. These may be evidence of galactic-scale outflows, where energy and matter are expelled from the central region, similar to how the Sun drives away particles in the solar wind. One of the most intriguing features is a thread of intertwined X-ray and radio emissions that stretches 20 light-years long but is remarkably thin, measuring only one-hundredth of that in width. These filamentary structures are thought to be shaped by the strong magnetic fields at the galaxy’s core.
Webb’s Unprecedented Infrared Detail
Adding another layer to our understanding, NASA’s James Webb Space Telescope (JWST) has captured a portion of the galaxy’s dense heart in unprecedented infrared detail. Its powerful NIRCam (Near-Infrared Camera) instrument peered into a star-forming region named Sagittarius C (Sgr C), located about 300 light-years from the Milky Way’s central supermassive black hole, Sagittarius A*. Because Webb’s infrared vision can cut through dust, it has revealed features that have never been seen before.
The resulting image is staggering in its density, showing an estimated 500,000 stars in a region just 50 light-years wide. According to Samuel Crowe, the principal investigator for the observations, the level of resolution and sensitivity is a first for this region. The galactic center, being about 25,000 light-years from Earth, is close enough for Webb to resolve individual stars. This allows astronomers to gather unparalleled data on how stars form in such an extreme environment and to investigate whether more massive stars tend to form in the galactic center compared to the quieter spiral arms.
Mysteries in the Star Nursery
Within the Sagittarius C image, Webb revealed a cluster of protostars—stars that are still forming and gaining mass—producing outflows that glow like a bonfire in the midst of an infrared-dark cloud. At the heart of this young cluster is a previously unknown, massive protostar more than 30 times the mass of our Sun. Webb’s data will enable astronomers to study how stars form in such a dense and turbulent environment. For instance, researchers are investigating why star formation rates in this region are lower than expected, despite the rich abundance of raw materials. One theory suggests that the powerful magnetic fields, visible in the MeerKAT data, may be suppressing star formation.
A Multi-Wavelength Future
Together, these distinct but complementary views from radio, X-ray, and infrared telescopes are providing a far more complete picture of the Milky Way’s core than ever before. While Webb reveals the intricate details of individual stars and star formation, Chandra uncovers the high-energy phenomena driven by magnetic fields and gas dynamics. Meanwhile, wide-field radio surveys like GLEAM-X trace the large-scale structures and the remnants of past cosmic events that have shaped the galaxy over millennia.
The insights gained from these projects lay the groundwork for the next generation of astronomical instruments. The data from GLEAM-X will inform research on a wide variety of subjects while setting a new benchmark for radio astronomy. However, its reign as the most detailed and sensitive image of its kind may be short-lived. A global collaboration is currently building the Square Kilometre Array Observatory (SKAO), a massive radio interferometer that promises to deliver the highest-resolution images in all of astronomy, pushing our understanding of the cosmos even further.