Properties of the remnant disk and the dynamical ejecta produced in low-mass black hole-neutron star mergers

Understand

We systematically perform numerical-relativity simulations for low-mass black hole-neutron star mergers for the models with seven mass ratios $Q=M_{\rm BH}/M_{\rm NS}$ ranging from 1.5 to 4.4, and three neutron-star equations of state, focusing on properties of matter remaining outside the black hole and ejected dynamically during the merger.

• We pay particular attention to the dependence on the mass ratio of the binaries.
• It is found that the rest mass remaining outside the apparent horizon after the merger depends only weakly on the mass ratio for the models with low mass ratios.
• It is also clarified that the rest mass of the ejecta has a peak at $Q \sim 3$, and decreases steeply as the mass ratio decreases for the low mass-ratio case.