GW190521 formation via three-body encounters in young massive star clusters

Understand

GW190521 is the most massive binary black hole (BBH) merger observed to date, and its primary component lies in the pair-instability (PI) mass gap.

• Here, we investigate the formation of GW190521-like systems via three-body encounters in young massive star clusters.
• We performed 2$\times10^5$ simulations of binary-single interactions between a BBH and a massive $\geq{60}\,$M$_{\odot}$ black hole (BH), including post-Newtonian terms up to the $2.5$ order and a prescription for relativistic kicks.
• In our initial conditions, we take into account the possibility of forming BHs in the PI mass gap via stellar collisions.