Preheating of the Universe by cosmic rays from primordial supernovae at the beginning of cosmic reionization

Understand

The 21-cm signal from the cosmic reionization epoch can shed light on the history of heating of the primordial intergalactic medium (IGM) at z~30-10.

• It has been suggested that X-rays from the first accreting black holes could significantly heat the Universe at these early epochs.
• Here we propose another IGM heating mechanism associated with the first stars.
• As known from previous work, the remnants of powerful supernovae (SNe) ending the lives of massive Population III stars could readily expand out of their host dark matter minihalos into the surrounding IGM, aided by the preceeding photoevaporation of the halo's gas by the UV radiation from the progenitor star.