“This is a really exciting result,” said Edward Cackett, a Wayne State University astronomer who was not involved in the study. “Although we have already seen the signature of the x-ray echoes, so far it has not been possible to separate the echo that comes from behind the black hole and leans into our line of sight. better mapping of how things fall in black holes and how black holes curve spacetime around them. “
The release of energy from black holes, sometimes in the form of x-rays, is an absurdly extreme process. And because supermassive black holes release so much energy, they’re essentially power plants that allow galaxies to grow around them. “If you want to understand how galaxies are formed, you really have to understand these processes outside of the black hole that are able to release these tremendous amounts of energy and power, these incredibly bright light sources that we are studying,” says Dan Wilkins, an astrophysicist at Stanford University and the study’s lead author.
The study focuses on a supermassive black hole at the center of a galaxy called I Zwicky 1 (I Zw 1 for short), about 100 million light years from Earth. In supermassive black holes like I Zw 1, large amounts of gas fall towards the center (the event horizon, which is essentially the point of no return) and tend to flatten into a disk. Above the black hole, a confluence of overcharged particles and magnetic field activity results in the production of high-energy x-rays.
Some of these x-rays shine directly on us, and we can observe them normally, using telescopes. But some of them also shine towards the flat gas disk and will reflect on it. The rotation of the black hole I Zw 1 slows down at a faster rate than that seen in most supermassive black holes, causing the surrounding gas and dust to fall more easily and feed the black hole in several directions. This, in turn, leads to greater X-ray emissions, which is why Wilkins and his team were particularly interested.
As Wilkins and his team observed this black hole, they noticed that the crown seemed to “blink.” These flashes, caused by x-ray pulses reflecting off the enormous gas disk, originated from behind the black hole’s shadow, a place that is normally hidden from view. But as the black hole curves the space around it, the x-ray reflections are also curved around it, which means we can spot them.
The signals were found using two different space telescopes optimized to detect X-rays in space: NuSTAR, managed by NASA, and XMM-Newton, managed by the European Space Agency.
The biggest implication of the new findings is that they confirm what Albert Einstein predicted in 1963 as part of his general theory of relativity – how light should bend around gigantic objects like supermassive black holes. .
“This is the first time that we really see the direct signature of the way the light leans behind the black hole in our line of sight, because of how the black hole distorts the space around it, ”says Wilkins.
“Although this observation does not change our general picture of the accretion of black holes, it is a nice confirmation that general relativity is at play in these systems,” says Erin Kara, astrophysicist at MIT who was not involved. in the study.
Despite their name, supermassive black holes are so far apart that they really look like single points of light, even with cutting-edge instruments. It will not be possible to take pictures of all as scientists used the Event Horizon telescope to capture the shadow of a supermassive blahck hole in it galaxy M87.
So, while it’s still early days, Wilkins and his team are hoping that detecting and studying more of these x-ray echoes from behind the turn could help us create partial images or even full of distant supermassive black holes. In turn, this could help them unravel great mysteries about how supermassive black holes grow, support entire galaxies, and create environments where the laws of physics are pushed to the limit.