A panoramic X-ray view, covering a 900 by 400 light year swath, shows that the center of the Galaxy is a teeming and tumultuous place. There are supernova remnants: SNR 0.9-0.1, probably the X-ray Thread, and Sagittarius A East. There are many bright X-ray sources, which astronomers believe are binary systems—or pairs of orbiting objects—that contain a black hole or a neutron star (the 1E sources). There are hundreds of unnamed point-like sources that scientists think are solo neutron stars or white dwarfs, which all light up the region. In addition, the massive stars in the Arches and other star clusters (the DB sources) will soon explode to produce more supernovas, neutron stars, and black holes.
Additional telescopes have also found other exotic members of this cosmic zoo. Infrared and radio instruments have revealed cooler, giant star-forming molecular clouds (Sagittarius A, B1, B2 and C, and the Cold Gas Cloud near the Radio Arc). The edges of these objects are glowing with X-rays (and, hence, detectable with Chandra) because of heating from nearby supernovas.
All this commotion takes place in a diffuse cloud of hot gas that shows up as extended X-ray emission. This diffuse X-ray glow gets brighter toward the Galactic Center. Sagittarius A (Sgr A), the bright blob in the center, is composed of three main parts: Sgr A East, Sgr A West, and Sgr A*. Sgr A East is the remnant of a supernova that stirred things up about 10,000 years ago. Sgr A West is a spiral-shaped structure of gas that may be falling toward Sgr A*, the supermassive black hole that marks the center of the Milky Way Galaxy. Sgr A* contains about 3 million times the mass of the Sun, and is gaining weight daily as it pulls in more material.