Here's how the largest galaxies die
Like it or not, all galaxies will eventually die. But have you wondered just how they meet their grisly ends? Researchers now have a good idea. They've studied 22 very large elliptical galaxies about 10 billion years old, and have discovered that these celestial bodies die from the inside out. The older they get, the more red giants (that is, dead stars) exist at their centers -- stars keep forming at the periphery up until the galaxy's last moments.
The observations should help identify just what prompts galaxies to die in the first place. Common theories suggest that galaxies either lose the flow of gas needed to make new stars, or that the black holes at the galaxies' hearts scatters the material and prevent it from gathering. Whatever the true causes, scientists will at least know which ideas make the most sense.
[Image credit: ESO]
