Tidal Deformability from GW170817 as a Direct Probe of the Neutron Star Radius

By C. Raithel, F. Özel, Dimitrios Psaltis. 2018

223 citations recorded by the source corpus.

Gravitational waves from the coalescence of two neutron stars were recently detected for the first time by the LIGO–Virgo Collaboration, in event GW170817. This detection placed an upper limit on the effective tidal deformability of the two neutron stars and tightly constrained the chirp mass of the system. We report here on a new simplification that arises in the effective tidal deformability of the binary, when the chirp mass is specified. We find that, in this case, the effective tidal deformability of the binary is surprisingly independent of the component masses of the individual neutron stars, and instead depends primarily on the ratio of the chirp mass to the neutron star radius. Thus, a measurement of the effective tidal deformability can be used to directly measure the neutron star radius. We find that the upper limit on the effective tidal deformability from GW170817 implies that the radius cannot be larger than ∼13 km, at the 90% level, independent of the assumed masses for the component stars. The result can be applied generally, to probe the stellar radii in any neutron star–neutron star merger with a measured chirp mass. The approximate mass independence disappears for neutron star–black hole mergers. Finally, we discuss a Bayesian inference of the equation of state that uses the measured chirp mass and tidal deformability from GW170817 combined with nuclear and astrophysical priors and discuss possible statistical biases in this inference.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/388e41bbca3ea38f8289f8420fd38a0842be5a6b

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

Citations in the corpus

Stellar structure models in modified theories of gravity: Lessons and challenges (2019, methodology): “rger GW170817 detected by the LIGO/VIRGO Collaboration [7] within the range 8.9 <r S <13.2km [420] (simulating thousands of piecewise polytropic EOS [421]), further supported by the analysis of [422] yielding the neutron star radius r S . 13km (90% conﬁdence level), which in turns allows to ru”
A NICER View of PSR J0030+0451: Implications for the Dense Matter Equation of State (2019, background): “Independent analyses of GW170817-only data (De et al. 2018) and results (e.g., Annala et al. 2018; Lim & Holt 2018; Most et al. 2018; Raithel et al. 2018; Tews et al. 2018b) obtained compatible constraints of the radius in a broad range of Rä[9, 14] km.”
Long-term GRMHD simulations of neutron star merger accretion discs: implications for electromagnetic counterparts (2018, background): “E-mail: rafernan@ualberta.ca 1 Also known as GRB170817A, SSS17a, AT 2017gfo, and DLT17ck & Metzger 2017; Rezzolla et al. 2018; Chatziioannou et al. 2018; Raithel et al. 2018; De et al. 2018; Abbott et al. 2018).”