Abbott, B P and Abbott, R and Somala, S N and et al, .
(2019)
Constraining the pModegMode Tidal Instability with GW170817.
Physical Review Letters, 122 (6).
ISSN 00319007
Full text not available from this repository.
(
Request a copy)
Abstract
We analyze the impact of a proposed tidal instability coupling p modes and g modes within neutron stars on GW170817. This nonresonant instability transfers energy from the orbit of the binary to internal modes of the stars, accelerating the gravitationalwave driven inspiral. We model the impact of this instability on the phasing of the gravitational wave signal using three parameters per star: An overall amplitude, a saturation frequency, and a spectral index. Incorporating these additional parameters, we compute the Bayes factor (lnB!pgpg) comparing our pg model to a standard one. We find that the observed signal is consistent with waveform models that neglect pg effects, with lnB!pgpg=0.030.58+0.70 (maximum a posteriori and 90% credible region). By injecting simulated signals that do not include pg effects and recovering them with the pg model, we show that there is a ≃50% probability of obtaining similar lnB!pgpg even when pg effects are absent. We find that the pg amplitude for 1.4 MâŠneutron stars is constrained to less than a few tenths of the theoretical maximum, with maxima a posteriori near oneTenth this maximum and pg saturation frequency ∼70 Hz. This suggests that there are less than a few hundred excited modes, assuming they all saturate by wave breaking. For comparison, theoretical upper bounds suggest a103 modes saturate by wave breaking. Thus, the measured constraints only rule out extreme values of the pg parameters. They also imply that the instability dissipates a1051 erg over the entire inspiral, i.e., less than a few percent of the energy radiated as gravitational waves.
[error in script]
Actions (login required)

View Item 