Chandra Release - October 12, 2001

Visual Description: M31

  This image shows the central portion of the Andromeda Galaxy in a larger X-ray field (upper left) with a pullout to a smaller field showing X-ray sources and optical light contours (lower right). At the center of the upper image, there is a bright, circular object that resembles a star. Surrounding this star, there are numerous small, bright dots, which appear to be evenly distributed across the image. These dots can be seen in different shades of purple, with some appearing brighter or dimmer than others and some with bright yellow cores. The blue dot in the center of the image is an unusually "cool" million degree X-ray source of unknown nature. Numerous other X-ray sources are also apparent. Most of these are probably due to X-ray binary systems, in which a neutron star or black hole is in a close orbit around a normal star. The pullout shows the three Chandra X-ray Observatory sources (white-gray) closest to the supermassive black hole, overlaid with the intensity contours from the Hubble image (red). The location of the supermassive black hole is thought to be in the middle of the peanut-shaped intensity contours, and very close to the northernmost of the three Chandra sources.