Galaxy's rapid growth spurt

摘要

Great galaxies can grow up fast. Huge quantities of magnesium in a quiet specimen called COSMOS 11494 reveal it was once one of the wildest star makers in the universe. The galaxy, 10.7 billion light years away, is the most distant one in which we've measured both magnesium and iron. These two elements indicate how quickly the galaxy has spawned stars. Magnesium is cast into space when short-lived massive stars blow up, whereas iron comes from white dwarfs that explode, a slower process.