The effect of noise artefacts on gravitational-wave searches for neutron star post-merger remnants

Abstract

Gravitational waves from binary neutron star post-merger remnants have the potential to uncover the physics of the hot nuclear equation of state. These gravitational-wave signals are high frequency ($\sim$ kHz) and short lived ($\mathcal{O}(10\,\mathrm{ms})$), which introduces potential problems for data-analysis algorithms due to the presence of non-stationary and non-Gaussian noise artefacts in gravitational-wave observatories. We quantify the degree to which these noise features in LIGO data may affect our confidence in identifying post-merger gravitational-wave signals. We show that the combination of vetoing data with non-stationary glitches and the application of the Allen $\chi^2$ veto (usually reserved for long-lived lower-frequency gravitational-wave signals), allows one to confidently detect post-merger signals with signal-to-noise ratio $\rho\gtrsim8$. We discuss the need to incorporate the data-quality checks and vetos into realistic post-merger gravitational-wave searches, and describe how one can incorporate them to calculate realistic false-alarm and false-dismissal rates.