# The effect of supernova asymmetry on coalescence rates of binary neutron stars

## TL;DR

This paper investigates how supernova asymmetry-induced kick velocities and neutron star spin alignments influence the coalescence rates of binary neutron stars, revealing significant reductions in expected rates and narrower spin-orbit misalignments.

## Contribution

It demonstrates that supernova kick asymmetries and spin alignments significantly affect binary neutron star coalescence rates and spin-orbit configurations.

## Key findings

- Coalescence rates can decrease by up to an order of magnitude due to kick effects.
- Large kick amplitudes and tight alignments have the strongest impact.
- Spin-kick correlation results in narrower spin-orbit misalignments.

## Abstract

We study the effect of the kick velocity -- neutron star spin alignment observed in young radio pulsars on the coalescence rate of binary neutron stars. The effect is shown to be especially strong for large kick amplitudes and tight alignments, reducing the galactic rate of binary neutron star coalescences up to an order of magnitude with respect to the rates calculated for random kicks. The spin-kick correlation also leads to much narrower NS spin-orbit misalignments compared to random kicks.