With a telescope VLA (Very Large Array, Corbella Antenna array), located in the U.S. state of new Mexico, astronomers from the National radio astronomy Observatory were able to see for the first time and get a clear image of the torus of one of the two supermassive black holes in the center of the radio galaxy, Cygnus A. As indicated in an article published in the journal Astrophysical Journal Letters, this observation confirms the theory of the single origin of all types of quasars.
According to modern concepts, at the center of every galaxy in the Universe is a supermassive black hole, are absorbed by matter (gas and dust) from an accretion disk around it. Part of this matter from time to time emitted by a black hole in a jet – thin beam of gas, accelerated almost to light speed, and has an enormous amount of energy in the form of optical and x-ray radiation.
Theory and computer modeling suggests that by itself a black hole and its accretion disk are enclosed in one very dense layer of matter in the form of a “doughnut” or toroid also of gas and dust, which prevents the spread of radiation from the jets, and keeps dust and gas inside the accretion disk. Thanks to his presence, similar to the galaxy will look to us in completely different ways, if you look at them from the side or top. Thus there was an assumption that all active galaxies, whose centers are quasars or blazara, we see that the hole in the “donut hole”, and the emissions of black holes in more relaxed clusters of stars are hidden from our view by a cocoon of dust and gas.
Some astronomers with this explanation do not agree, believing that the difference in the appearance of galaxies associated with yet unknown features of their nuclei. Chris Carilli and his team of astrophysicists at the National radio astronomy Observatory, in turn, were able to prove the sceptics wrong in this matter. To such conclusion scientists has summarized the observation of the Central part of the galaxy, Cygnus A, the study of which was carried out using the VLA radio telescope.
A couple of years ago the same group of scientists, literally, accidentally discovered in this galaxy the presence of one supermassive black hole. The discovery was made during the calibration of the equipment of the telescope, which by that time passed the next upgrade. The researchers decided to examine both objects in the center of a Swan and try to determine the traces of their possible interactions.
Due to the increased sensitivity and resolution of the new equipment VLT, astronomers were able to get the first clear images of the clusters of gas and dust in the form of a toroid around one of the black hole and its accretion disk. The observation of these objects was carried out at different frequencies. Then, the resulting image combined by filtering information associated with the radiation of the black hole and its accretion disk. Through such manipulations, the researchers were able to see the disc-shaped structure located at a distance from the intended center of a black hole. The researchers explain that the radius of this structure is about 860 light years and a thickness of about 900 light years.
Scientists are not sure what is the structure of this tor, however, the calculation of the ratios of its luminance and the estimated density indicate that it may be heterogeneous. According to the researchers, “donut”, consists of small clusters of clouds of gas and dust with different degrees of ionization and densities.
The proposed scheme structure of the “donut” of black holes
Carilli and his team believe that their research fully supports the theory of the common origin of all types of quasars. In the future, using other telescopes, the researchers plan to investigate chemical composition and structure of the torus of the black hole.
“We are glad that we were finally able to see the object in whose existence we have been long convinced. In order to understand its precise composition and shape, we will need to conduct a new observation. For example, using the ALMA telescope, we can map the distribution of dust and gas inside of it,” adds Carilli.