Astronomers conducted the original observations for a completely different purpose.
For the first time in the history of observations, astronomers have recorded X-rays reflected from the far side of the accretion disk surrounding a supermassive black hole. The source is located in the center of a galaxy about 800 million light-years away from us.
Spotting light behind a supermassive black hole for the first time in history
1. The purpose of observing the supermassive black hole in the center of the galaxy I Zwicky 1 was to study a mysterious feature inherent in only some of these gravitational monsters – the corona.
2. Extremely bright X-rays produced by a corona are believed to arise when gas approaches the event horizon, where it heats up to millions of degrees.
3. At such a high temperature, electrons are separated from atoms, creating a magnetized plasma, and the magnetic field arcs involved in the rapid rotation of the magnetic field bend and rise high upward, where in the end they are completely destroyed by its action.
4. Observations of the black hole were carried out using the NASA NuSTAR and ESA XMM-Newton X-ray telescopes. Astronomers initially identified two bright flares in the data.
5. Their analysis was carried out using a newly developed method, which is based on estimates of the displacement of the light length by the gravity of the black hole and the time delay between the initial signals and their copies reflected from the front of the accretion disk. This method made it possible to map the environment near the event horizon.
6. However, looking closely at the data, scientists noticed another series of weaker signals, which turned out to be the “echo” of the same X-ray bursts reflected from the far part of the disk of gas surrounding the black hole.
7. As scientists explain it, any light that enters a black hole should not be able to leave it, meaning that it should not be possible to see what’s behind a supermassive black hole.
8. Yet, the incredible properties of these gravitational monsters bend the space around them, deflect radiation, and more. This makes it possible to see the “reverse side” and in this case, the light behind the black hole.
9. Dan Wilkins, the lead author of the study at Stanford University (UK), explained that he has spent years working on new theoretical models about the echoes of X-ray flares in black holes. In other words, he was quick to trace the connection once he saw such in the latest data.
10. Astronomers intend to continue studying black hole crowns. They pin particular hopes on the Athena space telescope of the European Space Agency which is planned to launch in about a decade.