As the closest radio galaxy to Earth, Centaurus A is the perfect ‘cosmic laboratory’ to study the physical processes responsible for moving material and energy away from the galaxy’s core. Centaurus A is 10 million light-years away from Earth—just down the road in astronomical terms—and is a popular target for amateur and professional astronomers in the Southern Hemisphere due to its size, elegant dust lanes, and prominent plumes of material.
This work used the Murchison Widefield Array (MWA) and Parkes—these radio telescopes both have large fields of view, allowing them to image a large portion of sky and see all of Centaurus A at once. The MWA also has superb sensitivity allowing the large scale structure of Centaurus A to be imaged in great detail.
The MWA is a low frequency radio telescope located at the Murchison Radio-astronomy Observatory in Western Australia’s Mid West, operated by Curtin University on behalf of an international consortium. The Parkes Observatory is 64-metre radio telescope commonly known as “the Dish” located in New South Wales and operated by CSIRO. Observations from several optical telescopes were also used for this work— the Magellan Telescope in Chile, Terroux Observatory in Canberra, and High View Observatory in Auckland.
As well as the plasma that’s fuelling the large plumes of material the galaxy is famous for, we found evidence of a galactic wind that’s never been seen—this is basically a high speed stream of particles moving away from the galaxy’s core, taking energy and material with it as it impacts the surrounding environment.
By comparing the radio and optical observations of the galaxy the team also found evidence that stars belonging to Centaurus A existed further out than previously thought and were possibly being affected by the winds and jets emanating from the galaxy.