Formation of mass gap compact object and black hole binary from Population III stars

TL;DR

This study uses population synthesis simulations of Population III binary stars to explore the formation of mass gap compact objects and black hole binaries, revealing potential sources similar to GW190814.

Contribution

It introduces new simulation results on Population III star binaries, focusing on mass gap objects and their binary properties across various kick velocity models.

Findings

Mean mass of BH-MGCO binaries is approximately 30 and 2.6 solar masses.

Existence of BH-MGCO binaries with masses similar to GW190814.

Black hole-MGCO binaries are common across different kick velocity dispersions.

Abstract

We performed population synthesis simulations of Population III binary stars with Maxwellian kick velocity distribution when MGCOs (Mass Gap Compact Objects with mass 2--5$\,M_{\odot}$) are formed. We found that for eight kick velocity dispersion models of $\sigma_{\rm k}=0$--$500$ km/s, the mean mass of black hole (BH)-MGCO binary is $\sim (30 \,M_\odot,\,2.6 \,M_\odot)$. In numerical data of our simulations, we found the existence of BH-MGCO binary with mass $(22.9 \,M_\odot,\,2.5 \,M_\odot)$ which looks like GW190814.