Scientists announced on December 23, 2021 that they were using the Murchison Widefield Array (MWA) telescope in the Western Australia hinterland to produce the most complete picture to date of the black hole eruption in the galaxy Centaur A. This galaxy contains the closest active power supply a supermassive black hole down to earth. The black hole’s erupting radio bubble spans 16 full moons in our skies, despite being 12 million light years away.
As the black hole consumes stars and dust in this distant galaxy, it produces jets that throw matter at nearly speed of light, creating the giant radio bubbles. Radio bubbles are 8 degrees long (a full moon spans half a degree) and are hundreds of millions of years old.
New map shows black hole eruption
The Curtin Observatory in Australia operates radio telescopes from the Murchison Widefield Array. Benjamin mckinley from Curtin University was the lead author of the new study that produced the black hole map. McKinley describe the map:
These radio waves come from matter sucked into the supermassive black hole in the middle of the galaxy. It forms a disc around the black hole, and as matter tears apart as it approaches the black hole, powerful jets form on either side of the disc, ejecting most of the matter into space, at distances probably greater than a million light years. Previous radio observations could not handle the extreme brightness of the jets and the details of the larger area surrounding the galaxy were distorted, but our new image overcomes these limitations.
Centaurus A, the closest radio galaxy to us
Centaurus A, or NGC 5128, is an elliptical galaxy which is the closest radio galaxy to our own Milky Way. Because it’s relatively close to Earth, it’s a good target for astronomers to study the active supermassive black hole at its core. This black hole contains the mass of about 55 million suns and has incredible jets projecting up to 1.8 million light years.
We can learn a lot from Centaurus A in particular, just because it’s so close and we can see it in so much detail. Not just at radio wavelengths, but also at all other wavelengths of light. In this research, we were able to combine radio observations with optical and x-ray data to help us better understand the physics of these supermassive black holes.
Formation of radio jets
What is happening in this galaxy to create the huge jets? Massimo Gaspari from the Italian National Institute of Astrophysics said their study corroborated a theory called “Chaotic Cold Accretion.” Gaspari Explain:
In this model, clouds of cold gas condense in the galactic halo and rain down on central regions, fueling the supermassive black hole. Triggered by this rain, the black hole reacts vigorously by sending back energy via radio jets that inflate the spectacular lobes we see in the MWA image. This study is one of the first to probe multiphasic CCA in such detail. [Chaotic Cold Accretion] “Weather” on the whole range of scales.
McKinley describe how bright the center of the galaxy is where most of the activity and energy is, and:
â¦ Then it’s weaker as you go out because the energy has been lost and things have calmed down. But there are some interesting features where the charged particles have re-accelerated and interact with strong magnetic fields.
Scientists are eager to learn more about Centaurus A when the world’s largest radio telescope, the Square kilometer table, go online.
Conclusion: Scientists used the Murchison Widefield Array radio telescope to take the most detailed image yet of the huge nebulae surrounding the supermassive black hole at the center of the Centaurus A galaxy.