digital sky survey
How often do giant black holes become hyperactive?
A 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 ho…
Three Distant Quasars Found at Edge of the Universe
Astronomers have discovered three of the oldest, most distant quasars yet found — quasars close to the Big Bang that began the universe. Xiaohui Fan of the University of Arizona’s Steward Observatory in Tucson, Ariz., will present the results at the American Astronomical Society’s meeting in Seattle. Fan, leader of the team that discovered the objects, explained that these distant quasars — compact but luminous objects thought to be powered by super-massive black holes — reach back to a time when the universe was just 800 million years old. The highest redshift quasar is roughly 13 billion light years away and was discovered recently in the constellation Ursa Major.
Distant Ring of Stars Found Around the Milky Way
A previously unseen band of stars beyond the edge of the Milky Way galaxy has been discovered by a team of scientists from Rensselaer Polytechnic Institute, Fermi National Accelerator Laboratory, and the Sloan Digital Sky Survey (SDSS). The discovery could help to explain how the galaxy was assembled 10 billion years ago.