If you are lucky enough to witness a total eclipse, you will surely remember the bright halo of light around the moon during the total eclipse. It is known as the corona and is the diffuse outer atmosphere of the Sun. Although it is so thin that we can think of it as a vacuum on Earth, it has a temperature of millions of degrees and is therefore visible during a total eclipse.

According to our understanding of black hole dynamics, black holes should also have a corona. And like the Sun’s corona, it is often difficult to observe. Now, a study published in The Astrophysical Journal has revealed this elusive region. For an active black hole, the black hole is assumed to have a torus-shaped torus of gas and dust with an accretion disk of heated material aligned along the spin plane of the black hole.

Jets of ionized gas flow from the polar regions of the black hole at almost the speed of light.

This model can explain the different types of active galactic nuclei (AGN) we observe because the orientation of the black hole relative to us changes the appearance of the AGN. According to the model, the inner region of the accretion disk should be a superheated region of near-vacuum density flowing into the black hole.

It’s a corona like the sun, but its temperature is billions of degrees instead of millions of degrees. However, because it is so diffused, its light is blocked by the light of the accretion disk. In this new study, the team used a technique similar to observing the Sun’s corona during a total eclipse.

The orientation of the black hole relative to us means that for some black holes, the torus of gas and dust prevents us from seeing the accretion disk region, while for other black holes we can see the disk directly.

They are known as dimmed and non-dimmed black holes. Eclipsed black holes are similar to the eclipsed Sun because the light of the accretion disk is blocked from view. Unfortunately, the black hole’s corona is not like that either. But the corona is so hot that it emits extremely high-energy X-rays. These X-rays can scatter material in the torus and reflect back to our field line.

Using data from NASA’s Polarimetry X-ray Explorer (IPXE), the team identified a dozen eclipsed black holes in the Milky Way, including Cygnus Collected data about . Large Magellanic Cloud. Not only did they observe the scattered X-ray emission from the coronas of these black holes, they were also able to detect a pattern among them.

According to the data, instead of surrounding a black hole within a sphere similar to the Sun’s corona, the corona surrounds a black hole within a disk similar to an accretion disk. Such studies will help astronomers improve our black hole models. It will also help us better understand how black holes consume matter and fuel the AGNs we observe in distant galaxies.