Impact of Population III homogeneous stellar evolution on early cosmic reionisation

Understand

Context: Population III (Pop III) stars may be fast rotating.

• An expected consequence of fast rotation is strong internal mixing that deeply affects their evolutionary tracks in the Hertzsprung-Russell diagram and hence their ionising power.
• aims: We investigate the impact on the ionising power of Pop III stars in an extreme case of internal mixing, the one leading to chemically homogeneous evolution (CHE).
• In that situation, during the main sequence phase, the star keeps the same chemical composition from its center to its surface.