Figure 1

Comparison of the internal stellar structures of the \(\pmb{3 M_{\odot }}\) and \(\pmb{4 M_{\odot }}\) primary stars, as well as the \(\pmb{1 M_{\odot }}\) companion. Lines correspond to the one-dimensional models given by MESA, where the solid line is the companion star, the dot-dashed line is the \(3 M_{\odot }\) primary and the dashed line is the \(4 M_{\odot }\) primary. Overlaid in the same colour are points representing the densities calculated at the location of each SPH particle in the relaxed SPH models constructed from the MESA models (which excludes the neutron star at the origin).