Cosmic epoch · Cosmology
Reionization
Cosmology & UniverseActive Research
Definition
The era when radiation from the first stars and galaxies re-ionized the neutral hydrogen filling the Universe.
Scientific overview
Ultraviolet light from the earliest luminous objects stripped electrons from the intergalactic hydrogen, making the Universe transparent to ultraviolet light again. The timing and sources of reionization are actively being mapped.
Open questions
- What sources dominated reionization?
- How patchy was it in space and time?
Rests on
Measured by
Knowledge connections
- Depends onCosmic Dawn & the First Stars
- Part of modelThe Lambda-CDM Model
- Measured byJames Webb Space Telescope
- Measured byPlanck
- Preceded byCosmic Dawn & the First Stars
- Followed byStructure Formation
Sources & references
The primary and reference sources this topic draws on.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.