Retired Galaxies in the Young Universe
In the first few hundred million years after the Big Bang, the cosmos was like a noisy teen club: galaxies flared up, collided, and churned out stars by the hundreds.
The Mystery of 'Impossible' Galaxies: How Outer Color Maps Are Rescuing Cosmology
The first two billion years after the Big Bang were an era when the universe resembled a boiling construction pit. Dark matter clumped the gas together, igniting the first stars. It seemed there simply wasn't enough time to assemble massive elliptical galaxies—'dormant' stellar metropolises — from this raw material.