Astronomers discovered traces of a jet, which was emitted by supermassive black hole in the center of the Milky Way several thousand years ago. The discovery proves that the exotic object is not sleeping, and from time to time it becomes active when absorbing stars and gas. This is reported in the article published in the Astrophysical Journal magazine.
For the first time, the evidence of the short jet emanating from the southern pole of a black hole was obtained by the NASA CHANDRA X-ray observatory in 2013 and the VLA radio telescope (Very Large Array) in New Mexico (USA). This mini-jet, facing the interstellar medium, occurs when a black hole absorbs an array object, for example, a gas cloud.
Researchers checked if there are signs of the northern jet. With the help of the ALMA radio telescope complex, they found an expanding narrow linear structure in a molecular gas that was stretched for 15 light years. On infrared images obtained by the Hubble telescope, a hot gas bubble is also visible, which is located at a distance of 35 light years from a black hole. Scientists believe that the bubble arose due to the collision of mini jet with a hot gas cloud.
Since the jet is close enough to the black hole, it will become much more noticeable after a few decades after the object will again become active. Then the channel made by the jet, will again be filled with particles emitting electromagnetic radiation.