Reionization of the neutral gas in the universe occurred due to the
A) decay of dark matter particles.
B) emission of neutrinos by the first stars that formed.
C) heating from the motion of high-velocity black holes.
D) radiation from the first stars, supernovae, and black holes that formed.
E) positron and electron annihilations.

Question

Quizplus · Accepted Answer

Reionization occurred due to the radiation from the first stars, supernovae, and black holes, which emitted high-energy photons capable of ionizing the neutral hydrogen in the universe.

Reionization of the Neutral Gas in the Universe Occurred Due