The most detailed radio image of the galactic plane of the Milky Way


Combined observations from the ASKAP and Parkes telescopes in Australia have made it possible to observe in the greatest detail to date. a broad section of the galactic plane of the Milky Way.

Composite from the PEGASUS study, a group of radio astronomers led by Italy’s INAF (Istituto Nazionale di Astrofísica) used Parkes to “photograph” a large portion of our Galaxy’s disk, about 6-7 degrees or 12-14 full moons. This image was combined with another one produced with ASKAP for the EMU project led by Australia’s Macquarie University, resulting in an image of amazing quality.

The image shows a region with widespread emission associated with hydrogen gas filling the space between stars, dying stars called supernova remnants, and hot bubbles of ionized hydrogen gas associated with the birth of new stars. The stars themselves are not visible, since starlight contains minimal radio emission. This view of our Galaxy shows details of the birth and death of stars only visible to radio telescopes.

The data will help map the magnetic forces within our Milky Way Galaxy and allow us to study the history of magnetic forces in the Universe.

PEGASUS intends to use Parkes to map the entire southern sky at 700-1440 MHz with about 2100 observing hours. The PEGASUS project has just completed its pilot observations and intends to observe the entire southern sky in the next two years.

Soundings like PEGASUS look at the entire sky, including the Galactic Plane. The Galactic Plane is where the Solar System resides: it contains numerous stars, dust, and gas clouds, as well as a significant amount of dark matter. Studying the equator of the Milky Way has always been an essential goal for radio astronomers. Nevertheless, the diffuse emission of the Galaxy makes it difficult to obtain artifact-free images.

The image quality of this first observation is superb. EMU project manager Andrew Hopkins of Macquarie University explains it’s a statement: “The final results will be an unprecedented view of almost the entire Milky Wayabout a hundred times larger than this initial image, but achieving the same level of detail and sensitivity.”