Black holes are counter-intuitive things. They have such strong gravity that they absorb everything that comes close to them, even light, but they can still glow brightly in certain wavelengths due to emissions being given off at their event horizons. Astronomers have captured incredible emissions from a monster black hole with a mass equivalent to 55 million suns, which is giving off radio eruptions large enough to cover a portion of the sky the length of 16 moons.
The radio emissions are coming from the supermassive black hole at the heart of the galaxy Centaurus A, located 12 million light-years away, which is gobbling down gas. As the black hole consumes this gas it ejects material at extremely high speeds which gives rise to “radio bubbles” that grow and reach out into space.
Centaurus A is a giant elliptical active galaxy 12 million light-years away. At its heart lies a black hole with a mass of 55 million suns. This image shows the galaxy at radio wavelengths, revealing vast lobes of plasma that reach far beyond the visible galaxy, which occupies only a small patch at the center of the image. Ben McKinley, ICRAR/Curtin and Connor Matherne, Louisiana State University
“These radio waves come from material being sucked into the supermassive black hole in the middle of the galaxy,” lead author Dr. Benjamin McKinley of the International Centre for Radio Astronomy Research (ICRAR) explained in a statement. “It forms a disc around the black hole, and as the matter gets ripped apart going close to the black hole, powerful jets form on either side of the disc, ejecting most of the material back out into space, to distances of probably more than a million light-years.
“Previous radio observations could not handle the extreme brightness of the jets and details of the larger area surrounding the galaxy were distorted, but our new image overcomes these limitations.”
This composite image shows the Centaurus A galaxy and the surrounding intergalactic space at several different wavelengths. The radio plasma is displayed in blue and appears to be interacting with hot X-ray emitting gas (orange) and cold neutral hydrogen (purple). Clouds emitting Halpha (red) are also shown above the main optical part of the galaxy which lies in between the two brightest radio blobs. Connor Matherne, Louisiana State University (Optical/Halpha), Kraft et al. (X-ray), Struve et al. (HI), Ben McKinley, ICRAR/Curtin. (Radio)
One reason to study Centaurus A is that it is the closest radio galaxy to our Milky Way, making it an ideal target for research. “We can learn a lot from Centaurus A in particular, just because it is so close and we can see it in such detail,” Dr. McKinley said. “Not just at radio wavelengths, but at all other wavelengths of light as well. In this research we’ve been able to combine the radio observations with optical and x-ray data, to help us better understand the physics of these supermassive black holes.”
The research is published in the journal Nature Astronomy.