New multi-messenger constraints on the neutron star equation of state
The paper “Constraining the neutron star equation of state using multi-band independent measurements of radii and tidal deformabilities” by Margherita Fasano, Tiziano Abdelsalhin, Andrea Maselli and Valeria Ferrari, has been recently accepted on Physical Review Letters.
Gravitational wave signals from coalescing binaries offer a new window on the features of the neutron star equation of state at supra-nuclear densities, which is nowadays still uncertain. The first binary event GW170917 has already provided new clues in this direction, ruling out extreme cases of stiff matter. These results can be complemented by current and future electromagnetic surveys of neutron stars by space satellites, leading to multi-messenger constraints of the stellar structure.
In the recently accepted PRL, Fasano and collaborators have proposed a new data analysis strategy to pursue such multi-messenger quest, which allows to combine any neutron star observable measured in the gravitational wave and in the electromagnetic band. The authors have proved how this approach, supplied by detections of sources featuring different masses and astrophysical environments, can greatly improve our knowledge on the equation of state. By applying the new strategy to the data inferred from GW170917 and from spectroscopic observations of low mass X-ray binaries, Fasano and collaborators have derived new bounds on features of the the stellar structure, which are among the strongest constraints derived so far.
Reference
Constraining the neutron star equation of state using multi-band independent measurements of radii and tidal deformabilities
Phys. Rev. Lett. 123 no. 14, 141101 (2019)
[https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.141101]