Astronomers at Australian National University (ANU) said on November 28, 2017 that they’ve created the most detailed radio image yet of the Small Magellanic Cloud, a famous sky-sight from Earth’s Southern Hemisphere and a dwarf galaxy orbiting our home galaxy, the Milky Way. The image shows the galaxy not in terms of its stars and dust, as optical images do, but in terms of its hydrogen gas. ANU astronomer Naomi McClure-Griffiths, who co-led the study, said:
Hydrogen is the fundamental building block of all galaxies and shows off the more extended structure of a galaxy than its stars and dust.
She said the image reveals distortions to the Small Magellanic Cloud, which likely occurred because of its interactions with the larger galaxies and because of its own star explosions that push gas out of the galaxy:
The outlook for this dwarf galaxy is not good, as it’s likely to eventually be gobbled up by our Milky Way.
Together, the [Large and Small] Magellanic Clouds are characterised by their distorted structures, a bridge of material that connects them, and an enormous stream of hydrogen gas that trails behind their orbit – a bit like a comet.
The astronomers said their new radio image helps them understand how the Small Magellanic Cloud – and presumably the several dozen dwarf galaxies orbiting our Milky Way – formed and evolved.
The Commonwealth Scientific and Industrial Research Organization (CSIRO) – the federal government agency for scientific research in Australia – acquired the image via its new radio telescope, called the Australian Square Kilometre Array Pathfinder (ASKAP). Naomi McClure-Griffiths said:
The new image … reveals more gas around the edges of the galaxy, indicating a very dynamic past for the Small Magellanic Cloud. These features are more than three times smaller than we were able to see before and allow us to probe the detailed interaction of the small galaxy and its environment.
The new image (top of post) was created as part of a survey that aims to study the evolution of galaxies.
Bottom line: Astronomers at Australian National University have created the most detailed radio image yet of the Small Magellanic Cloud.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.