Astronomers have carried out an analysis of obscured black holes of distant galaxies.
Scientists usually struggle to distinguish between the emissions of obscured black holes and those of their host galaxies. One of main reasons for this problem is that as supermassive black holes grow, they swallow up the surrounding mass. The dust created in the process absorbs X-ray emitted by the black hole and, in turn, radiate infrared.
However, Harvard astronomers Francesca Civano and Stefano Marchesi have devised a way to identify obscured black holes by calculating the ratio of infrared and X-ray emissions.
The researchers noted that the nucleus area of obscured black holes are more compact than that of star-forming galaxies. The nuclei of obscured black holes appear contracted.
According to the researchers, this could be the reason why the nuclear region of galaxies appeared compact during the early stages of the universe.
This study was published by the Harvard-Smithsonian Center for Astrophysics.