In a remarkable advancement for cosmic mapping, astronomers from the International Center for Radio Astronomy Research (ICRAR) have introduced the most comprehensive low-frequency radio color image of the Milky Way to date. This image is not just another typical star photograph; it represents a vibrant tapestry constructed from the unseen “colors” of radio light, revealing the Southern Hemisphere”s perspective of our galaxy with exceptional clarity.
PhD student Sylvia Mantovanini dedicated 18 months, utilizing over one million CPU hours on supercomputers at the Pawsey Supercomputing Research Center, to create this image. Her work was based on data from two extensive sky surveys, GLEAM and GLEAM-X, conducted with the Murchison Widefield Array (MWA) telescope located on Wajarri Yamaji Country in Western Australia.
“This vibrant image delivers an unparalleled perspective of our Galaxy at low radio frequencies,” Mantovanini stated. “It provides valuable insights into the evolution of stars, including their formation in various regions of the Galaxy, how they interact with other celestial objects, and ultimately their demise.”
The newly unveiled image boasts double the resolution, tenfold sensitivity, and increased sky coverage compared to its 2019 predecessor. This enhanced detail enables astronomers to explore deeper into the hidden layers of the Milky Way, distinguishing between newly formed stars and the remnants of those that have exploded.
“You can clearly identify remnants of exploded stars, represented by large red circles, while the smaller blue regions indicate stellar nurseries where new stars are actively forming,” Mantovanini explained. Her research particularly focuses on supernova remnants, which are the luminous clouds that remain after stars meet their dramatic end. Although hundreds have been documented, it is believed that thousands more may still be concealed within the galaxy.
The image also offers potential for unraveling the enigmas surrounding pulsars, which are rotating stellar corpses that emit radio waves like cosmic beacons. By monitoring their brightness across GLEAM-X frequencies, scientists aim to gain a better understanding of these mysterious objects and their locations.
Associate Professor Natasha Hurley-Walker, the principal investigator of the GLEAM-X survey, described the image as a significant milestone. “This low-frequency image allows us to unveil large astrophysical structures in our Galaxy that are challenging to capture at higher frequencies,” she noted.
“No low-frequency radio image of the entire Southern Galactic Plane has been published before, marking this as a thrilling milestone in astronomy,” she added.
The surveys conducted cataloged 98,000 radio sources across the southern Galactic Plane, including pulsars, planetary nebulae, compact HII regions, dense ionized gas clouds, and distant galaxies beyond the Milky Way”s confines. While this image establishes a new benchmark for astronomical imaging, it is only the beginning.
“Only the world”s largest radio telescope, the SKA Observatory”s SKA-Low telescope, which is expected to be completed in the next decade on Wajarri Yamaji Country in Western Australia, will have the ability to surpass this image in terms of sensitivity and resolution,” concluded Associate Professor Hurley-Walker.
For further reference, see the study titled “GaLactic and Extragalactic All-sky Murchison Widefield Array survey eXtended (GLEAM-X) III: Galactic Plane,” published in the Publications of the Astronomical Society of Australia.
