Gravitational waves from Population III binary black holes are consistent with LIGO/Virgo O3a data for the chirp mass larger than $\sim 20M_{\odot}$

Understand

The probability number distribution function of binary black hole mergers observed by LIGO/Virgo O3a has double peaks as a function of chirp mass $M_c$, total mass $M_t$, primary black hole mass $M_1$ and secondary one $M_2$, respectively.

• The larger chirp mass peak is at $M_c \cong 30 M_{\odot}$.
• The distribution of $M_2$ vs.
• $M_1$ follows the relation of $M_2\cong 0.7M_1$.