Reionization

150 million – 1 billion years · Structure Formation

Temperature (K): 30
When: 150 million – 1 billion years
Redshift: z ≈ 20 – 6
Era: Structure Formation
Seconds After Big Bang: 15778465000000000

What Happened

Ultraviolet light from the first stars and quasars strips the electrons back off the intergalactic hydrogen it took recombination so long to assemble. The universe becomes transparent to ultraviolet for the second and final time.

Researchers

Abraham Loeb Xiaohui Fan Rennan Barkana Bruce Peterson Richard Ellis James Gunn

Equations

Einstein A and B Coefficients Planck's Law Saha Ionization Equation

Theories

Stellar Nucleosynthesis Big Bang Cosmology

Referenced by

equation

Einstein A and B Coefficients Planck's Law Saha Ionization Equation

researcher

Abraham Loeb Bruce Peterson James Gunn Rennan Barkana Richard Ellis Xiaohui Fan

theory

Big Bang Cosmology Stellar Nucleosynthesis

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From the Cosmic Timeline database in Notion, last edited 2026-08-16. This page is the row, rendered by the build; nothing on it is written by hand.