X-rays of the giant rings show how dust is distributed in our galaxy: it does not look like household dust, but rather looks like smoke from tiny particulate matter.
The black hole in the image is part of the V404 Cygni binary system: it is located about 7.8 thousand light-years from Earth. The black hole actively attracts particles of the companion star. This dust glows in X-rays, which is why astronomers call these systems “double X-rays.”
On June 5, 2015, astronomers through the Svift telescope detected an X-ray burst from the V404 Cygni system. Because of the explosion, rings of high energy were formed, in other words, a light echo. The light echo around V404 Cygni occurred when a burst of X-rays from a black hole system bounced off dust rings between V404 Cygni and Earth.
Dust rings tell astronomers not only about the behavior of the black hole, but also provide information about what is happening between V404 Cygni and Earth. For example, the diameter of the rings indicates the distance to the intermediate dust clouds from which the light bounced. If the cloud is closer to the Earth, then the ring appears larger, and vice versa.
The researchers also used the rings to study the properties of the dust clouds themselves. They compared their X-ray spectra, that is, the brightness of X-rays in the wavelength range, with computer models of dust of different compositions. The different compositions of dust can cause the X-rays to be simply absorbed, so the telescope cannot transmit information.
The team determined that the dust in the image was likely composed of a mixture of graphite and silicate grains. In addition, the density of dust clouds is not the same, although previous studies have suggested that this is not the case.