Population synthesis of neutron star X-ray binaries associated with supernova remnants

TL;DR

This study uses population synthesis models to explore the characteristics and expected numbers of young neutron star X-ray binaries associated with supernova remnants, focusing on different companion star types.

Contribution

It provides the first comprehensive simulation of NS XRB populations with SNRs, including various companion star types and their properties.

Findings

Most NS XRBs with SNRs are Be X-ray binaries.

A few BeXRBs are predicted to be associated with SNRs in the Milky Way.

Estimated birthrates and orbital distributions for different companion types.

Abstract

Neutron star X-ray binaries (NS XRBs) associated with supernova remnants (SNRs) are the youngest X-ray binaries that can provide insights into the early evolution of X-ray binaries and the formation properties of neutron stars. There are an increasing number of NS XRBs discovered to be harbored in SNRs in our and nearby galaxies. In this work, we perform binary population synthesis calculations to simulate the population of NS XRBs associated with SNRs for different types of companions, including Roche-lobe overfilling main-sequence stars, Be stars and supergiants. We estimate their birthrates and present the distributions of orbital parameters and companion mass for each type of companions. Our calculations show that the majority of them are Be X-ray binaries (BeXRBs) and that a few BeXRBs are expected to be associated with SNRs in a Milky Way-type galaxy.