Impact of Population III stars on the astrophysical gravitational-wave background

Understand

We probe the astrophysical gravitational-wave background resulting from compact binary coalescences, focusing on Population III binary black holes.

• We exploit results of state-of-the-art simulations on the evolution of Population I-II and III binaries, considering a variety of initial condition and star formation rate models for the latter.
• The contribution from Population III binary black holes is found to be very small, with no effect on the gravitational-wave spectrum.
• A network of third-generation detectors will detect easier individual Population III binaries, due to their significantly higher masses, hence decreasing even further their residual contribution.