Two streams of giant plasma flow from the supermassive black hole at the center of the neighboring galaxy Centaurus A. The origin of this so-called Planes it is now Photographed with unprecedented detail by Event Horizon Telescope (EHT), which was previously Take the first picture of a black hole.
Centaurus A is an interesting galaxy because it has two bright radio planes and because it is relatively close – only 13 million light-years away. It is one of the largest and brightest sources of radio emissions in the sky.
At its center is a supermassive black hole 55 million times more massive than the Sun. This is where the two planes that exceed the size of the galaxy are created. If we could see radio waves with the naked eye, Centaurus A planes would be sixteen times the size of a full moon in the sky. While they are much further away, he says Michael Jansen, researcher at the German Max Planck Institute in the field of radio.
Zoom
Janssen led EHT research in Centaurus A aircraft during his doctoral research at Radboud University in Nijmegen. The research team used EHT observations of 2017 to zoom in on the core of Centaurus A. The EHT is a collaboration of eight radio telescopes scattered around the world, to form an Earth-sized telescope.
Because this galaxy is so close, the EHT has allowed astronomers to image the jets at a scale less than a light day. This is the distance a ray of light travels in a day. This seems poor accuracy – for example, the Sun is eight light minutes from Earth. But they are distances that we as humans can begin to understand. It’s close to the size of the solar system, Jansen says. The EHT observations are also sixteen times sharper than previous observations of Centaurus A.
Mysterious planes
The jets in supermassive black holes, such as those in Centaurus A, are created by the strong gravitational pull of gas and dust toward the black holes. This material spins as a hot, energy-rich mass in a disk around the black hole before most of it disappears into it. Due to the huge amount of energy and strong magnetic fields that are created, a tiny bit of matter can escape from the disk. This part of the universe is injected at nearly the speed of light in two narrow beams. It is not yet clear how the magnetic fields that fire jets are created and affect.
“We are interested in these jets because we believe that black holes can affect the large structure of the universe through jets,” he said. Sera Markov, Professor of High Energy Astrophysics at the University of Amsterdam and Associate at EHT. “It has a lot of energy and it has a tremendous range.”
light edges
What is of interest in the EHT observations of Centaurus A are the edges of the brightly lit planes. This has been seen before, for example with the black hole jets of the galaxy M87 in the first image of the EHT. But in Centaurus A, the difference in light between the edges and the dark center of the planes is even more extreme.
“Using the M87s, we were able to describe the shape of the slightly lighter planes and edges using our theoretical models,” says Markov. We’ve tried the same thing with Centaurus A. But we can’t theoretically explain why the edges are so light. So we will have to make better and more detailed models.
On top of that, the research group used the observations to determine the likely location of the black hole in Centaurus A. Will we also soon get a nice picture of this, like the black hole of M87? Unfortunately no. “It turns out that’s impossible with telescopes coming from the ground,” Jansen says. New satellites are needed to image this black hole at a sufficiently high resolution.
