Astronomers using CSIRO’s Australian Square Kilometre Array Pathfinder (ASKAP) at the Murchison Radio-Astronomy Observatory in Australia have created the most detailed radio image of a nearby dwarf galaxy called the Small Magellanic Cloud, revealing secrets of how it formed and how it is likely to evolve.
Atomic hydrogen gas in the Small Magellanic Cloud as imaged with CSIRO’s Australian Square Kilometre Array Pathfinder. Image credit: Australian National University / CSIRO.
The Small Magellanic Cloud, a dwarf galaxy that is a satellite of our Milky Way Galaxy, is located about 210,000 light-years away in the southern constellation of Tucana.
It has a complex structure due to gravitational interaction with the Milky Way and the Large Magellanic Cloud.
“The new image captured by the ASKAP telescope reveals more gas around the edges of the Small Magellanic Cloud, indicating a very dynamic past for this dwarf galaxy,” said co-lead researcher Professor Naomi McClure-Griffiths, from the Research School of Astronomy and Astrophysics at the Australian National University.
“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.”
“This stunning image showcases the wide field of view of the ASKAP telescope, and augurs well for when the full array will come on-line next year,” said CSIRO spokesperson Dr. Philip Edwards.
The new radio image of the Small Magellanic Cloud was created as part of a survey that aims to study the evolution of galaxies.
“Distortions to this dwarf galaxy occurred because of its interactions with the larger galaxies and because of its own star explosions that push gas out of the galaxy,” Professor McClure-Griffiths said.
“The outlook for the galaxy is not good, as it’s likely to eventually be gobbled up by our Milky Way.”
“Together, the Magellanic Clouds are characterized 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.”
According to Professor McClure-Griffiths and colleagues, the new image finally reaches the same level of detail as infrared images from NASA’s Spitzer Space Telescope and ESA’s Herschel telescope, but on a very different component of the galaxy’s make-up — its hydrogen gas.
“Hydrogen is the fundamental building block of all galaxies and shows off the more extended structure of a galaxy than its stars and dust,” Professor McClure-Griffiths said.
