Colour-composite images of the host galaxies of three of 30 newly found dust-enshrouded supermassive black holes. To the left images taken with the Advanced Camera for Surveys onboard the NASA/ESA Hubble Space Telescope. To the right these images are overlaid with images (in blue) from NASA's Chandra X-ray Observatory. Note that the actual black holes themselves are not visible in the images, however X-ray radiation can escape from a violently active region very close to the black hole.

Credit: ESA/NASA, the AVO project and Paolo Padovani