June 1, 2004: Astronomers unveiled the deepest images from NASA's new Spitzer Space Telescope today, and announced the detection of distant objects — including several supermassive black holes — that are nearly invisible in even the deepest images from telescopes operating at other wavelengths.See the rest:
Supermassive black holes formed early in the universe and accompanied galaxy formation. Hubble research finds that they are common among galaxies. They are millions or billions of times more massive than black holes that are left behind after a star explodes.
AGNs active galactic nuclei are supermassive black holes that are accreting gas. The black hole heats the gas to millions of degrees, where it glows in X-rays. This makes the region around the black hole glow brightly across the universe.
Black holes were well-fed in the early universe. There was a lot of gas from them to accrete from galaxy collisions, which were more frequent when the expanding universe was smaller, so very distant galaxies are more likely to have AGNs.
Black holes can be hidden behind dusty, donut-shaped features, which are common in AGNs. Or, they can be so far away that all their light is stretched into the infrared region of the spectrum.