Tito Dal Canton

The PyCBC search for gravitational waves from compact binary coalescence

We describe the PyCBC search for gravitational waves from compactobject binary coalescences in advanced gravitational-wave detector data. The search was used in the first Advanced LIGO observing run and unambiguously identified two black hole binary mergers, GW150914 and GW151226. At its core, the PyCBC search performs a matched-filter search for binary merger signals using a bank of gravitational-wave template waveforms. We provide a complete description of the search pipeline including the steps used to mitigate the effects of noise transients in the data, identify candidate events and measure their statistical significance. The analysis is able to measure false-alarm rates as low as one per million years, required for confident detection of signals. Using data from initial LIGO’s sixth science run, we show that the new analysis reduces the background noise in the search, giving a 30% increase in sensitive volume for binary neutron star systems over previous searches.

Implementing a search for aligned-spin neutron star-black hole systems with advanced ground based gravitational wave detectors

detectors, and an estimate of the rate of background events. We restrict attention to neutron star{black hole (NS-BH) binary systems, and we compare a search using non-spinning templates to one using templates that include spins aligned with the orbital angular momentum. To run the searches we implement the binary inspiral matched-lter computation in PyCBC, a new software toolkit for gravitational-wave data analysis. We nd that the inclusion of aligned-spin eects signicantly increases the astrophysical reach of the search. Considering astrophysical NS-BH systems with non-precessing black hole spins, for dimensionless spin components along the orbital angular momentum uniformly distributed in ( 1; 1), the sensitive volume of the search with aligned-spin templates is increased by 50% compared to the non-spinning search; for signals with aligned spins uniformly distributed in the range (0:7; 1), the increase in sensitive volume is a factor of 10.

Detecting Binary Compact-object Mergers with Gravitational Waves: Understanding and Improving the Sensitivity of the PyCBC Search

We present an improved search for binary compact-object mergers using a network of ground-based gravitational-wave detectors. We model a volumetric, isotropic source population and incorporate the resulting distribution over signal amplitude, time delay, and coalescence phase into the ranking of candidate events. We describe an improved modeling of the background distribution, and demonstrate incorporating a prior model of the binary mass distribution in the ranking of candidate events. We find a

Impact of precession on aligned-spin searches for neutron-tar-black-hole binaries

\sim 10\%

Electromagnetic Chirps from Neutron Star-Black Hole Mergers

and

Sensitivity of gravitational wave searches to the full signal of intermediate mass black hole binaries during the LIGO O1 Science Run

\sim 20\%

Stochastic template bank for gravitational wave searches for precessing neutron-star–black-hole coalescence events

increase in detection volume for simulated binary neutron star and neutron star--binary black hole systems, respectively, corresponding to a reduction of the false alarm rates assigned to signals by between one and two orders of magnitude.

Rapid detection of gravitational waves from compact binary mergers with PyCBC Live

The inclusion of aligned-spin effects in gravitational-wave search pipelines for neutron-star--black-hole binary coalescence has been shown to increase the astrophysical reach with respect to search methods where spins are neglected completely, under astrophysically reasonable assumptions about black-hole spins. However, theoretical considerations and population synthesis models suggest that many of these binaries may have a significant misalignment between the black-hole spin and the orbital angular momentum, which could lead to precession of the orbital plane during the inspiral and a consequent loss in detection efficiency if precession is ignored. This work explores the effect of spin misalignment on a search pipeline that completely neglects spin effects and on a recently-developed pipeline that only includes aligned-spin effects. Using synthetic but realistic data, which could reasonably represent the first scientific runs of advanced-LIGO detectors, the relative sensitivities of both pipelines are shown for different assumptions about black-hole spin magnitude and alignment with the orbital angular momentum. Despite the inclusion of aligned-spin effects, the loss in signal-to-noise ratio due to precession can be as large as

Gravitational waves: search results, data analysis and parameter estimation: Amaldi 10 Parallel Session C2

40\%

Designing a template bank to observe compact binary coalescences in Advanced LIGO's second observing run

, but this has a limited impact on the overall detection rate: even if precession is a predominant feature of neutron-star--black-hole binaries, an aligned-spin search pipeline can still detect at least half of the signals compared to an idealized generic precessing search pipeline.