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We use gravitational-wave observations of the binary neutron star merger GW170817 to explore the tidal deformabilities and radii of neutron stars. We perform a Bayesian parameter estimation with the source location and distance informed by electromagnetic observations. We also assume that the two stars have the same equation of state; we demonstrate that, for stars with masses comparable to the component masses of GW170817, this is effectively implemented by assuming that the stars' dimensionless tidal deformabilities are determined by the binary's mass ratio q by Λ_{1}/Λ_{2}=q^{6}. We investigate different choices of prior on the component masses of the neutron stars. We find that the tidal deformability and 90% credible interval is Λ[over Ë]=222_{-138}^{+420} for a uniform component mass prior, Λ[over Ë]=245_{-151}^{+453} for a component mass prior informed by radio observations of Galactic double neutron stars, and Λ[over Ë]=233_{-144}^{+448} for a component mass prior informed by radio pulsars. We find a robust measurement of the common areal radius of the neutron stars across all mass priors of 8.9≤R[over ^]≤13.2 km, with a mean value of ⟨R[over ^]⟩=10.8 km. Our results are the first measurement of tidal deformability with a physical constraint on the star's equation of state and place the first lower bounds on the deformability and areal radii of neutron stars using gravitational waves.
RESUMEN
This corrects the article DOI: 10.1103/PhysRevLett.121.091102.
RESUMEN
A simple method for determining the focal ratio degradation of optical fibers has been developed. The method involves splitting the light from the test fiber and recording ring patterns that have traveled over two different, and known, optical paths. This new method will be valuable for testing many fibers as will be needed for new multiobject astronomical spectrographs.