When galaxies no longer form new stars, their end begins and they pass – albeit slowly. A group of astronomers has now discovered a galaxy that ejects the necessary matter with great force and thus ushers in its comparatively imminent end.

The discovery was made almost by chance, the researchers now explain. Every year the distant galaxy ID 2299 loses gas, the 10. 000 corresponds to suns and because they are still forming stars very quickly at the same time, this will no longer be possible in a few tens of millions of years because the material for it has run out. The “spectacular loss of gas” is the result of a collision with another galaxy, say the researchers.

Beginning and end Like the scientists explain, most experts actually assume that star-forming material is thrown from galaxies by winds, which have their origin in star formation and gigantic black holes. In the course of long periods of time, they lose the matter from which new stars can emerge and finally disappear when the existing stars have come to an end.

Galactic collisions have not yet been identified as processes that likewise can initiate such an end and, above all, such a rapid one. The ALMA radio telescope used has “shed new light on the mechanisms that can bring star formation in distant galaxies to a standstill.”

Dying galaxy The rapidly dying galaxy ID 2299 is so far away from us that we can see it in a state when the universe was only 4.5 billion years old. It was only targeted for a few minutes during a major survey. Nevertheless, their unusual condition was recognized. They found the giant, so-called “tidal tail”.

These are gigantic flows of gas and stars that extend between galaxies and are remnants of galaxies. Most of the time these are not bright enough to be seen from such a long distance. In the case of ID 2299 it was so bright that you could identify it and determine its origin. The researchers present their findings in the journal Nature Astronomy.

(mho)