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Abstract

We find that the Hanford and Livingston detectors of Advanced LIGO derive
distinct posterior probability distribution of binary tidal deformability
tilde{Lambda} of the first binary-neutron-star merger GW170817. By analyzing
public data of GW170817 with a nested-sampling engine and the default TaylorF2
waveform provided by the LALInference package, the probability distribution of
the binary tidal deformability derived by the LIGO-Virgo detector network turns
out to be determined dominantly by the Hanford detector. Specifically, by
imposing the flat prior on tidal deformability of individual stars, symmetric
90% credible intervals of tilde{Lambda} are estimated to be 527^{+619}_{-345}
with the Hanford detector, 927^{+522}_{-619} with the Livingston detector, and
455^{+668}_{-281} with the LIGO-Virgo detector network. Furthermore, the
distribution derived by the Livingston detector changes irregularly when we
vary the maximum frequency of the data used in the analysis. This feature is
not observed for the Hanford detector. While they are all consistent, the
discrepancy and irregular behavior suggest that an in-depth study of noise
properties might improve our understanding of GW170817 and future events.