Formation, disruption and energy output of Population III X-ray binaries

Understand

The first astrophysical objects shaped the cosmic environment by reionizing and heating the intergalactic medium (IGM).

• In particular, X-rays are very efficient at heating the IGM before it became completely ionized, an effect that can be measured through the 21 cm line of neutral hydrogen.
• High-mass X-ray binaries (HMXBs), known to be prolific X-ray sources in star-forming galaxies at lower redshifts, are prime candidates for driving the thermal evolution of the IGM at redshifts $z > 20$.
• Despite their importance, the formation efficiency of HMXBs from the first stellar populations is not well understood---as such, their collective X-ray emission and the subsequent imprint on the 21 cm signature are usually evaluated using free parameters.