The Population III origin of GW190521

摘要: We explore the possibility that recently detected black hole binary (BHB) merger event GW190521 originates from first generation of massive, metal-free, so-called Population III (Pop III), stars. Based on improved statistics derived N-body simulations Pop star clusters, we calculate rate densities BHBs similar to GW190521, in two evolution channels: classical stellar and dynamical hardening high-redshift nuclear clusters. Both channels can explain observed density. But latter is favoured by better agreement with observation less restrictions uncertain parameters. Our analysis also indicates given distinct features (with rates peaked at $z\lesssim2$ $z\sim 10$, respectively), future BHB mergers third-generation gravitational wave detectors will greatly improve our knowledge BHBs, especially for their dynamics during cosmic structure formation.