Joint population and equation-of-state inference of neutron stars observed electromagnetically and via gravitational waves

We observe a population of Galactic neutron stars via their electromagnetic radiation, and separately a population of merging neutron stars via their gravitational-wave emission. Due to different formation and evolutionary histories, the Galactic and merging neutron-star mass distributions are distinct and should be treated separately. However, a universal equation of state governs the mass-radius relationship of neutron stars, and in particular controls their maximum stable mass. Building on previous work, we infer the mass distributions of Galactic and merging neutron stars jointly with the universal equation of state. For the first time, we incorporate neutron stars observed via gravitational waves merging with black holes into the analysis.