In 2010, astronomers working with the Fermi Gamma-Ray Space Telescope unveiled a previously unseen structure centered in the Milky Way that spans 50,000 light-years that may be the remnant of an eruption from the supermassive black hole at the center of our galaxy. The structure spans more than half of the visible sky, a region roughly as large as the Milky Way itself, and it may be millions of years old, its origin an unsolved mystery.
In images collected from 2016 to 2018 and in 2012, researchers have found two plumes of X-rays — galactic center chimneys — stretching in opposite directions from the central hub of the galaxy. Each plume originates within about 160 light-years of the supermassive black hole and spans over 500 light-years.