TY - JOUR

T1 - Properties of the Binary Neutron Star Merger GW170817

AU - Abbott, B. P.

AU - Pitkin, M.

AU - LIGO Scientific Collaboration and Virgo Collaboration

PY - 2019/1/2

Y1 - 2019/1/2

N2 - On August 17, 2017, the Advanced LIGO and Advanced Virgo gravitational-wave detectors observed alow-mass compact binary inspiral. The initial sky localization of the source of the gravitational-wave signal,GW170817, allowed electromagnetic observatories to identify NGC 4993 as the host galaxy. In this work, weimprove initial estimates of the binary’s properties, including component masses, spins, and tidal parameters,using the known source location, improved modeling, and recalibrated Virgo data. We extend the range ofgravitational-wave frequencies considered down to 23 Hz, compared to 30 Hz in the initial analysis. We alsocompare results inferred using several signal models, which are more accurate and incorporate additionalphysical effects as compared to the initial analysis. We improve the localization of the gravitational-wavesource to a 90% credible region of 16 deg2. We find tighter constraints on the masses, spins, and tidalparameters, and continue to find no evidence for nonzero component spins. The component masses areinferred to lie between 1.00 and 1.89 M⊙ when allowing for large component spins, and to lie between 1.16and 1.60 M⊙ (with a total mass 2.73þ0.04 −0.01 M⊙) when the spins are restricted to be within the range observed inGalactic binary neutron stars. Using a precessing model and allowing for large component spins, weconstrain the dimensionless spins of the components to be less than 0.50 for the primary and 0.61 for thesecondary. Under minimal assumptions about the nature of the compact objects, our constraints for the tidaldeformability parameter Λ˜ are (0,630) when we allow for large component spins, and 300þ420−230 (using a 90%highest posterior density interval) when restricting the magnitude of the component spins, ruling out severalequation-of-state models at the 90% credible level. Finally, with LIGO and GEO600 data, we use a Bayesiananalysis to place upper limits on the amplitude and spectral energy density of a possible postmerger signal.

AB - On August 17, 2017, the Advanced LIGO and Advanced Virgo gravitational-wave detectors observed alow-mass compact binary inspiral. The initial sky localization of the source of the gravitational-wave signal,GW170817, allowed electromagnetic observatories to identify NGC 4993 as the host galaxy. In this work, weimprove initial estimates of the binary’s properties, including component masses, spins, and tidal parameters,using the known source location, improved modeling, and recalibrated Virgo data. We extend the range ofgravitational-wave frequencies considered down to 23 Hz, compared to 30 Hz in the initial analysis. We alsocompare results inferred using several signal models, which are more accurate and incorporate additionalphysical effects as compared to the initial analysis. We improve the localization of the gravitational-wavesource to a 90% credible region of 16 deg2. We find tighter constraints on the masses, spins, and tidalparameters, and continue to find no evidence for nonzero component spins. The component masses areinferred to lie between 1.00 and 1.89 M⊙ when allowing for large component spins, and to lie between 1.16and 1.60 M⊙ (with a total mass 2.73þ0.04 −0.01 M⊙) when the spins are restricted to be within the range observed inGalactic binary neutron stars. Using a precessing model and allowing for large component spins, weconstrain the dimensionless spins of the components to be less than 0.50 for the primary and 0.61 for thesecondary. Under minimal assumptions about the nature of the compact objects, our constraints for the tidaldeformability parameter Λ˜ are (0,630) when we allow for large component spins, and 300þ420−230 (using a 90%highest posterior density interval) when restricting the magnitude of the component spins, ruling out severalequation-of-state models at the 90% credible level. Finally, with LIGO and GEO600 data, we use a Bayesiananalysis to place upper limits on the amplitude and spectral energy density of a possible postmerger signal.

U2 - 10.1103/PhysRevX.9.011001

DO - 10.1103/PhysRevX.9.011001

M3 - Journal article

VL - 9

JO - Physical Review X

JF - Physical Review X

SN - 2160-3308

IS - 1

M1 - 011001

ER -