|NGC 3115 - "Spindle Galaxy" Imaged on T13|
by Insight Observatory.
In 1992, Astronomers John Kormendy of the University of Hawaii and Douglas Richstone of the University of Michigan announced what was observed to be a supermassive black hole in the galaxy. Based on orbital velocities of the stars in its core, the central black hole has mass measured to be approximately one billion solar masses. The galaxy appears to have mostly old stars and little or no activity. The growth of its black hole has appeared to have stopped.
In 2011, NASA's Chandra X-ray Observatory examined the black hole at the center of the large galaxy. A flow of hot gas toward the supermassive black hole has been imaged, making this the first time clear evidence for such a flow has been observed in any black hole. As gas flows toward the black hole, it becomes hotter and brighter. The researchers found the rise in gas temperature begins at about 700 light-years from the black hole. This suggests that the black hole in the center of NGC 3115 has a mass of about two billion solar masses, supporting previous results from optical observations. This would make NGC 3115 the nearest billion-solar-mass black hole to Earth.
Fact Source: Wikipedia