Population Properties of Gravitational-Wave Neutron Star--Black Hole Mergers

Understand

Over the course of the third observing run of LIGO-Virgo-KAGRA Collaboration, several gravitational-wave (GW) neutron star--black hole (NSBH) candidates have been announced.

• By assuming these candidates are real signals and of astrophysical origins, we analyze the population properties of the mass and spin distributions for GW NSBH mergers.
• We find that the primary BH mass distribution of NSBH systems, whose shape is consistent with that inferred from the GW binary BH (BBH) primaries, can be well described as a power-law with an index of $\alpha = 4.8^{+4.5}_{-2.8}$ plus a high-mass Gaussian component peaking at $\sim33^{+14}_{-9}\,M_\odot$.
• The NS mass spectrum could be shaped as a near flat distribution between $\sim1.0-2.1\,M_\odot$.