Scientists have long suspected that it is powered by a supermassive black hole with 2.6 million times the mass of our Sun. This beautiful high resolution radio image covers a 4x4 degree region around the galactic center. The X-rays would come from hot gas in an accretion disk swirling into the dense gravitational field of the hole. Previous X-ray satellites lacked the combined resolution and sensitivity to make this basic test. But now, thanks to the Chandra X-ray Observatory, astronomers finally have the data they've been waiting for.
Theorists are eager to hear the results of our observation so they can test their ideas.
As the high energy X rays stream away from the vicinity of the black hole, they heat the blanketing gas to temperatures of a few million degrees, and the blanket absorbs some of the X rays from the central source. This produces dark stripes, or absorption lines in the X-ray spectrum. Bright stripes or emission lines due to emission from the blanketing gas are also present. Since each element has its own unique structure, these lines can be read like a cosmic bar code to take inventory of the gas. The team was able to determine what atoms the gas contains and how many, the number of electrons each atom has retained in the hostile environment of the black hole, and how the gas is moving there.