One black hole or a pair? Dust clouds hide the secrets of galactic nuclei

One black hole or a pair? Dust clouds hide the secrets of galactic nuclei

An artistic vision of how an active galactic nucleus can look when it comes together. The accretion disk creates a bright light in the center. The wide line area is located just above the accretion disk and is lost in bright light. Dust clouds move up due to intense radiation.

University of California researchers believe that dust clouds, rather than double black holes, will be an explanation for unusual observations in active galactic nuclei (AGN). Many large galaxies have AGN - a small bright central region, fed by matter falling into a supermassive black hole. With vigorous absorption around the black holes accumulates hot rapidly moving gas - the area of ​​the wide line.

Emission from this gas is one of the best sources of information about the mass of the central black hole and the process of its growth. But the nature of the gas is still mysterious. The breakdown of some models led researchers to the idea that many AGNs are capable of having not one, but two black holes.

New analysis is trying to solve the problem. Scientists believe that a pair of black holes is a seeming picture created by the presence of small dust clouds that overshadow AGNs and distort observations. The gas rotating towards the central black hole forms a flat “accretion disk”, and the hot gas on this disk releases intense thermal radiation. Part of the world is “recycled” (absorbed and re-emitted) by hydrogen and other gases circulating above the accretion disk in the wide line. Above and below it is the area of ​​dust. The effect of dust clouds on the emitted light is to make the incoming light more faint and red. The same thing happens on Earth with the Sun, which seems more blurry and red at sunset. Scientists have created computer code to simulate the effects of these dust clouds to observe the wide-line area.

Researchers have shown that the addition of dust clouds to the model makes it possible to reproduce many features of the radiation from the broadband region, which had previously confused physicists. The gas does not pass through the asymmetric distribution, it is simply located in a symmetric turbulent disk around a black hole. The presence of a dust cloud makes these regions look fainter and redder. This is a more natural theory than exotic explanations, like double black holes.

Comments (0)