SPACE.com — NASA Completes Survey of Nearby Supermassive Black Holes
A new census compiled by astronomers contains the location of every local galaxy with a supermassive black hole at its center.
“We are confident we are seeing every, active supermassive black hole within 400-million-light-years of Earth,” said Jack Tueller of NASA Goddard Space Flight Center in Maryland who led the census effort.
Called active galactic nuclei, or AGN, these black holes have masses of up to billions of Suns compressed into a region about the size of our solar system. The all-sky census [image], performed using NASA’s Swift satellite over a nine-month period, detected more than 200 nearby AGN. [More]
