Cosmology · Galaxies
Reionization
Say it: ree-eye-uh-nye-ZAY-shun IPA: /riˌaɪənaɪˈzeɪʃən/ noun
Reionization: The process that ionized much of the universe's intergalactic gas again after an earlier neutral period.
Early in cosmic history, electrons joined atomic nuclei and much hydrogen became neutral. Later radiation from luminous sources stripped electrons away again across expanding regions of space.
- Example
- The distant galaxy was studied for clues to the era of reionization.
- Why astronomers use it
- It connects the emergence of luminous objects with a major change in the gas between galaxies.
- Tiny cosmic connection
- Reionization concerns the state of cosmic gas; it is not the formation of new chemical elements.
Deep Space Cosmology Galaxies
Where to check it
- NASA Science: Universe glossary (opens in a new tab)
- NASA Hubble glossary (opens in a new tab)
- Wikipedia: Reionization (opens in a new tab)
Written for Cool Moon Facts in its own words; the sources cover the same idea in more depth.