Chandra X-ray Images of Bootes Field
This Chandra survey, taken in a region of the Bootes constellation, reveals over a thousand black holes that are up to several billion times more massive than the Sun. These black holes lie in the centers of galaxies that are between 6 and 11 billion light years away. The different colors indicate whether the black holes are surrounded by a thick ring of material or not. These results give astronomers a snapshot of a crucial period when these monster black holes are growing, and provide insight into the environments in which they occur.
(Credit: NASA/CXC/CfA/R.Hickox et al.)

X-ray, IR & Optical Composites of Obscured & Unobscured AGN in Bootes Field
These images show four black holes from the Bootes field. The first two black holes are obscured by thick rings of gas. Because such a ring blocks certain types of radiation, these black holes are only are seen in X-ray (blue) and infrared (red) light. The last two black holes are not enshrouded by this ring of material, and, therefore, emit X-ray, infrared, and optical (green) radiation. These objects helps astronomers better understand the properties of these monster black holes.
(Credit: X-ray: NASA/CXC/CfA/R.Hickox et al.; Infrared: NASA/JPL/Caltech/P.Eisenhardt & D.Stern et al.; Optical: NOAO/B.Jannuzi & A.Dey et al.)