A new analysis of x-rays streaming from the bright center of a
galaxy has strengthened the case that a supermassive black hole
lurks there. The x-rays imply that their source, a spinning disk
of gas, surrounds an object with a density only a black hole
could reach. The research, reported in tomorrow's Nature,
represents the most unambiguous scrutiny to date of the bizarre
environment close to a large black hole's maw and supports
claims of supermassive black holes in other galaxies. The Hubble
Space Telescope has already found signs that enormous black
holes dwell in the centers of some galaxies by spying stars
swirling near their cores, as if around powerful gravitational
drains. Two years ago, researchers used x-ray telescopes aboard
a Japanese satellite called ASCA to gain an even more direct
view. The satellite detected radiation from glowing iron atoms
moving at fantastic speeds--at least 20% of the speed of light--
within a flattened doughnut of gas at the core of a galaxy
called MCG-6-30-15. The doughnu