Early galaxies were surrounded by giant clouds of hydrogen, and astronomers have discovered massive clouds of hydrogen.

The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) is located outside of Austin, Texas. Credit: HETDEX/UT Austin

Based on the Big Bang cosmology and the LCDM model, the most widely accepted models for the beginning of the universe, scientists theorize that a huge cloud of neutral hydrogen permeated the universe. From this material, the first stars and galaxies rapidly formed over the next several hundred eons, an event that astronomers and cosmologists … Read more