Hyper-Active Black Holes: The Most Dangerous Object in the Universe?

Hyper-Active Black Holes: The Most Dangerous Object in the Universe?: "lA new study from NASA's Chandra X-ray Observatory tells scientists how often the biggest black holes have been active over the last few billion years. This discovery clarifies how supermassive black holes grow and could have implications for how the giant black hole at the center of the Milky Way will behave in the future."