1. early stages of galaxy formation in the universe, consisting of large clouds of gas and dark matter that eventually collapse to form galaxies
Usage: astronomy; plural form

Examples

• Astronomers detected protogalaxies forming just a few billion years after the Big Bang.
• The Hubble telescope captured images of distant protogalaxies in various stages of development.
• These protogalaxies contained mostly hydrogen and helium gas before star formation began.
• Computer simulations show how protogalaxies merge to create larger galactic structures.
• Scientists study protogalaxies to understand how the first galaxies in the universe formed.
• The gravitational collapse of protogalaxies led to the birth of the earliest stars.