Stars have ceased to be born in the most massive galaxies in the universe. To continue growing, these “devour” other nearby galaxies.
This is established by a study carried out by a team of Australian astronomers who have investigated the evolution of 22,000 of these objects. As these experts advance in the Monthly Notices of the Royal Astronomical Society magazine, while in smaller galaxies new stars are generated from gas very efficiently , the rate of star formation is much lower in larger ones.
Aaron Robotham, from the Center for Radio Astronomy Research at the University of Western Australia, who coordinated the trial, says the Milky Way is precisely at a tipping point.
“Our galaxy has not merged with another in a long time, but you can still see the remains of those it has swallowed,” he says. Robotham points out that soon, in cosmic terms, his greatest star contribution will come from this peculiar diet.
“ In 4,000 million years, it will absorb the Magellanic Clouds , two dwarf galaxies that belong to our Local Group, and 1,000 million years later it will collide with Andromeda. Technically, it will have eaten us, since this is more massive than ours ”, he indicates. “Over time, gravity will encourage all galaxies to clump together into a few superstructures.”
Researchers are not sure why the most massive galaxies have become “sterile.” One of the most widespread hypotheses suggests that these objects have a very active nucleus that prevents the gas from cooling sufficiently, thus preventing new stars from emerging.
