The center of the Milky Way shows little activity in contrast. It was not always so peaceful. New evidence of ghost beams of gamma rays suggests that the central black hole of our galaxy was much more active in the past.
"These jets are
faint ghost or just a sequel to what existed for millions of years," said
Meng Su, an astronomer at the Harvard-Smithsonian Center for Astrophysics
(CfA), and author of a new article in the Astrophysical Journal. "But it
reinforces the evidence that there was an active galactic nucleus in the
relatively recent past of the Milky Way," he added.