TY - JOUR

T1 - The gravitational wave 'probability event horizon' for double neutron star mergers

AU - Coward, David

AU - Lilley, M.

AU - Howell, Eric

AU - Burman, Ron

AU - Blair, David

PY - 2005

Y1 - 2005

N2 - Gravitational waves generated by the final merger of double neutron star (DNS) binary systems are a key target for the gravitational wave (GW) interferometric detectors, such as LIGO (Laser Interferometer Gravitational-wave Observatory), and the next generation detectors, Advanced LIGO. The cumulative GW signal from DNS mergers in interferometric data will manifest as 'geometrical noise': a non-continuous stochastic background with a unique statistical signature dominated by the spatial and temporal distribution of the sources. Because geometrical noise is highly non-Gaussian, it could potentially be used to identify the presence of a stochastic GW background from DNS mergers. We demonstrate this by fitting to a simulated distribution of transients using a model for the DNS merger rate and idealized Gaussian detector noise. Using the cosmological 'probability event horizon' concept and recent bounds for the Galactic DNS merger rate, we calculate the evolution of the detectability of DNS mergers with observation time. For Advanced LIGO sensitivities and a detection threshold assuming optimal filtering, there is a 95 per cent probability that a minimum of one DNS merger signal will be detectable from the ensemble of events comprising the stochastic background during 12-211 d of observation. For initial LIGO sensitivities, we identify an interesting regime where there is a 95 per cent probability that at least one DNS merger with signal-to-noise ratio greater than unity will occur during 4-68 d of observation. We propose that there exists an intermediate detection regime with pre-filtered signal-to-noise ratio less than unity, where the DNS merger rate is high enough that the geometrical signature could be identified in interferometer data.

AB - Gravitational waves generated by the final merger of double neutron star (DNS) binary systems are a key target for the gravitational wave (GW) interferometric detectors, such as LIGO (Laser Interferometer Gravitational-wave Observatory), and the next generation detectors, Advanced LIGO. The cumulative GW signal from DNS mergers in interferometric data will manifest as 'geometrical noise': a non-continuous stochastic background with a unique statistical signature dominated by the spatial and temporal distribution of the sources. Because geometrical noise is highly non-Gaussian, it could potentially be used to identify the presence of a stochastic GW background from DNS mergers. We demonstrate this by fitting to a simulated distribution of transients using a model for the DNS merger rate and idealized Gaussian detector noise. Using the cosmological 'probability event horizon' concept and recent bounds for the Galactic DNS merger rate, we calculate the evolution of the detectability of DNS mergers with observation time. For Advanced LIGO sensitivities and a detection threshold assuming optimal filtering, there is a 95 per cent probability that a minimum of one DNS merger signal will be detectable from the ensemble of events comprising the stochastic background during 12-211 d of observation. For initial LIGO sensitivities, we identify an interesting regime where there is a 95 per cent probability that at least one DNS merger with signal-to-noise ratio greater than unity will occur during 4-68 d of observation. We propose that there exists an intermediate detection regime with pre-filtered signal-to-noise ratio less than unity, where the DNS merger rate is high enough that the geometrical signature could be identified in interferometer data.

U2 - 10.1111/j.1365-2966.2005.09613.x

DO - 10.1111/j.1365-2966.2005.09613.x

M3 - Article

SN - 0035-8711

VL - 364

SP - 807

EP - 812

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

IS - 3

ER -