Half of the Milky Way turned out to be extragalactic

The international team of astronomers has established that up to half the matter of the Milky Way has extragalactic origin.

"It is likely that most of the matter of the Milky Way was in other galaxies and traveled through the intergalactic space before it was knocked out by a powerful wind and eventually found its new home in the Milky Way."

Scientists believe that matter moved between galaxies at a speed of hundreds of kilometers per second, and filling the Milky Way with a foreign substance took several billion years.

To detailed conclusions, astronomers came by carrying out on the supercomputer a simulation that reproduced the formation of the Milky Way. Scientists were primarily interested in the origin of matter, from which the stars appear.