Compact binary waveform recovery from the cross-correlated data of two detectors by matched filtering with spinning templates

We investigate whether the recovery chances of highly spinning waveforms by matched filtering with randomly chosen spinning waveforms generated with the LAL package are improved by a cross-correlation of the simulated output of the L1 and H1 LIGO detectors. We find that a properly defined correlated overlap improves the mass estimates and enhaces the recovery of spin angles

Extending the PyCBC search for gravitational waves from compact binary mergers to a global network

The worldwide advanced gravitational-wave (GW) detector network has so far primarily consisted of the two Advanced LIGO observatories at Hanford and Livingston, with Advanced Virgo joining the 2016-7 O2 observation run at a relatively late stage. However Virgo has been observing alongside the LIGO detectors since the start of the O3 run; in the near future, the KAGRA detector will join the global network and a further LIGO detector in India is under construction. Gravitational-wave search methods would therefore benefit from the ability to analyse data from an arbitrary network of detectors. In this paper we extend the PyCBC offline compact binary coalescence (CBC) search analysis to three or more detectors, and describe resulting updates to the coincident search and event ranking statistic. For a three-detector network, our improved multi-detector search finds 20% more simulated signals at fixed false alarm rate in idealized colored Gaussian noise, and up to 40% more in real data, compared to the two-detector analysis previously used during O2

Calibration of the Advanced LIGO detectors for the discovery of the binary black-hole merger GW150914

In Advanced LIGO, detection and astrophysical source parameter estimation of the binary black hole merger GW150914 requires a calibrated estimate of the gravitational-wave strain sensed by the detectors. Producing an estimate from each detector's differential arm length control loop readout signals requires applying time domain filters, which are designed from a frequency domain model of the detector's gravitational-wave response. The gravitational-wave response model is determined by the detector's opto- mechanical response and the properties of its feedback control system. The measurements used to validate the model and characterize its uncertainty are derived primarily from a dedicated photon radiation pressure actuator, with cross-checks provided by optical and radio frequency references. We describe how the gravitational-wave readout signal is calibrated into equivalent gravitational-wave-induced strain and how the statistical uncertainties and systematic errors are assessed. Detector data collected over 38 calendar days, from September 12 to October 20, 2015, contain the event GW150914 and approximately 16 days of coincident data used to estimate the event false alarm probability. The calibration uncertainty is less than 10% in magnitude and 10° in phase across the relevant frequency band, 20 Hz to 1 kHz

Searches for continuous gravitational waves from nine young supernova remnants

science data run. The targets were nine young supernova remnants not associated with pulsars; eight of the remnants are associated with non-pulsing suspected neutron stars. One target’s parameters are uncertain enough to warrant two searches, for a total of ten. Each search covered a broad band of frequencies and first and second frequency derivatives for a fixed sky direction. The searches coherently integrated data from the two LIGO interferometers over time spans from 5.3–25.3 days using the matched-filtering F-statistic. We found no credible gravitational-wave signals. We set 95% confidence upper limits as strong (low) as 4 × 10−25 on intrinsic strain, 2 × 10−7 on fiducial ellipticity, and 4 × 10−5 on r-mode amplitude. These beat the indirect limits from energy conservation and are within the range of theoretical predictions for neutron-star ellipticities and r-mode amplitudes.Fil: Dominguez, Alfredo Eduardo. Ministerio de Defensa. Fuerza Aerea Argentina; ArgentinaFil: Ortega Larcher, Walter Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estrategico Para la Defensa. Subsede Instituto Universitario Aeronautico | Ministerio de Defensa. Unidad de Investigación y Desarrollo Estrategico Para la Defensa. Subsede Instituto Universitario Aeronautico; ArgentinaFil: Aasi, J.. California Institute of Technology; Estados UnidosFil: Abbott, B. P.. California Institute of Technology; Estados UnidosFil: Abbott, R.. California Institute of Technology; Estados UnidosFil: Abbott, T.. State University of Louisiana; Estados UnidosFil: Abernathy, M. R.. California Institute of Technology; Estados UnidosFil: Acernese, F.. Universita di Salerno; Italia. Istituto Nazionale Di Fisica Nucleare; ItaliaFil: Ackley, K.. University of Florida; Estados UnidosFil: Adams, C.. Livingston Observatory; Estados UnidosFil: Adams, T.. Cardiff University; Reino Unido. Centre National de la Recherche Scientifique; Francia. Université de Savoie; FranciaFil: Adams, T.. Centre National de la Recherche Scientifique; Francia. Université de Savoie; FranciaFil: Addesso, P.. University of Sannio at Benevento; Italia. Istituto Nazionale Di Fisica Nucleare; ItaliaFil: Adhikari, R. X.. California Institute of Technology; Estados UnidosFil: Adya, V.. Max Planck Institut für Gravitationsphysik; AlemaniaFil: Affeldt, C.. Max Planck Institut für Gravitationsphysik; AlemaniaFil: Agathos, M.. Nikhef; Países BajosFil: Agatsuma, K.. Nikhef; Países BajosFil: Aggarwal, N.. Massachusetts Institute of Technology; Estados UnidosFil: Aguiar, O. D.. Centro de Previsao de Tempo e Estudos Climáticos. Instituto Nacional de Pesquisas Espaciais; BrasilFil: Ain, A.. Inter-University Centre for Astronomy and Astrophysics; IndiaFil: Ajith, P.. Tata Institute of Fundamental Research; IndiaFil: Alemic, A.. Syracuse University; Estados UnidosFil: Allen, B.. University of Wisconsin-Milwaukee; Estados Unidos. Max-Planck-Institut für Gravitationsphysik; AlemaniaFil: Allocca, A.. Università degli Studi di Siena; Italia. Istituto Nazionale Di Fisica Nucleare; ItaliaFil: Amariutei, D.. University of Florida; Estados UnidosFil: Anderson, S. B.. California Institute of Technology; Estados UnidosFil: Anderson, W. G.. University of Wisconsin–Milwaukee; Estados UnidosFil: Arai, K.. California Institute of Technology; Estados UnidosFil: Araya, M. C.. California Institute of Technology; Estados Unido

Narrow-band search of continuous gravitational-wave signals from Crab and Vela pulsars in Virgo VSR4 data

In this paper we present the results of a coherent narrow-band search for continuous gravitational-wave signals from the Crab and Vela pulsars conducted on Virgo VSR4 data. In order to take into account a possible small mismatch between the gravitational-wave frequency and two times the star rotation frequency, inferred from measurement of the electromagnetic pulse rate, a range of 0.02 Hz around two times the star rotational frequency has been searched for both the pulsars. No evidence for a signal has been found and 95% confidence level upper limits have been computed assuming both that polarization parameters are completely unknown and that they are known with some uncertainty, as derived from x-ray observations of the pulsar wind torii. For Vela the upper limits are comparable to the spin-down limit, computed assuming that all the observed spin-down is due to the emission of gravitational waves. For Crab the upper limits are about a factor of 2 below the spin-down limit, and represent a significant improvement with respect to past analysis. This is the first time the spin-down limit is significantly overcome in a narrow-band search