Paper published by B. P. Abbott et al. (LIGO Scientific Collaboration and Virgo Collaboration) in Physical Review Letters.
GW170817: Measurements of Neutron Star Radii and Equation of State
On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were neutron stars that are described by the same equation of state and have spins within the range observed in Galactic binary neutron stars. Our analysis employs two methods: the use of equation-of-state-insensitive relations between various macroscopic properties of the neutron stars and the use of an efficient parametrization of the defining function p(ρ) of the equation of state itself.
Figure. Marginalized posterior for the tidal deformabilities of the two binary components of GW170817. The green shading shows the posterior obtained using the Λa (Λs,q) EOS-insensitive relation to impose a common EOS for the two bodies, while the green, blue, and orange lines denote 50% (dashed) and 90% (solid) credible levels for the posteriors obtained using EOS-insensitive relations, a parametrized EOS without a maximum mass requirement, and independent EOSs (taken from [52]), respectively. The gray shading corresponds to the unphysical region Λ2<Λ1 while the seven black scatter regions give the tidal parameters predicted by characteristic EOS models for this event.
Paper link available below at citation information
Citation:
B. P. Abbott et al. (LIGO Scientific Collaboration and Virgo Collaboration)
GW170817: Measurements of Neutron Star Radii and Equation of State
Phys. Rev. Lett. 121, 161101
DOI: https://doi.org/10.1103/PhysRevLett.121.161101
15 October 2018
