supermassive black hole
Swift survey finds ‘missing’ active galaxies
Seen in X-rays, the entire sky is aglow. Even far away from bright sources, X-rays originating from beyond our galaxy provide a steady glow in every direction. Astronomers have long suspected that the chief contributors to this cosmic X-ray ba…
Case for Massive Black Hole Strengthened
UCLA astronomer Andrea Ghez announced more than four years ago that a monstrous black hole resides at the center of our Milky Way galaxy, 24,000 light years away, with a mass more than 2 million times that of our sun. Some astronomers greeted the announcement with skepticism, and proposed exotic forms of matter as alternatives. At the American Association for the Advancement of Science meeting Feb. 16 in Denver, Ghez reported that the case for the black hole has been strengthened substantially, and that all of the proposed alternatives can be excluded.
Milky Way monster stars in cosmic reality show
The longest X-ray look yet at the supermassive black hole at the Milky Way’s center has given astronomers unprecedented access to its life and times. The new data from NASA’s Chandra X-ray Observatory revealed that our galaxy’s central black hole is a frequent bad actor, prone to numerous outbursts and occasional large explosions.