arXiv subjects

T. Cokelaer

Publications and source records attributed to T. Cokelaer.

4 recordsLinked to original sources

arXiv2012

Searching for gravitational waves from binary coalescence

We describe the implementation of a search for gravitational waves from compact binary coalescences in LIGO and Virgo data. This all-sky, all-time, multi-detector search for binary coalescence has been used to search data taken in recent LIGO and Virgo runs. The search is built around a matched filter analysis of the data, augmented by numerous signal consistency tests designed to distinguish artifacts of non-Gaussian detector noise from potential detections. We demonstrate the search performance using Gaussian noise and data from the fifth LIGO science run and demonstrate that the signal consistency tests are capable of mitigating the effect of non-Gaussian noise and providing a sensitivity comparable to that achieved in Gaussian noise.

gr-qc↗

arXiv2008

Beating the spin-down limit on gravitational wave emission from the Crab pulsar

We present direct upper limits on gravitational wave emission from the Crab pulsar using data from the first nine months of the fifth science run of the Laser Interferometer Gravitational-wave Observatory (LIGO). These limits are based on two searches. In the first we assume that the gravitational wave emission follows the observed radio timing, giving an upper limit on gravitational wave emission that beats indirect limits inferred from the spin-down and braking index of the pulsar and the energetics of the nebula. In the second we allow for a small mismatch between the gravitational and radio signal frequencies and interpret our results in the context of two possible gravitational wave emission mechanisms.

astro-ph↗

arXiv2006

A template bank to search for gravitational waves from inspiralling compact binaries I: physical models

Gravitational waves from coalescing compact binaries are searched using the matched filtering technique. As the model waveform depends on a number of parameters, it is necessary to filter the data through a template bank covering the astrophysically interesting region of the parameter space. The choice of templates is defined by the maximum allowed drop in signal-to-noise ratio due to the discreteness of the template bank. In this paper we describe the template-bank algorithm that was used in the analysis of data from the Laser Interferometer Gravitational Wave Observatory (LIGO) and GEO 600 detectors to search for signals from binaries consisting of non-spinning compact objects. Using Monte-Carlo simulations, we study the efficiency of the bank and show that its performance is satisfactory for the design sensitivity curves of ground-based interferometric gravitational wave detectors GEO 600, initial LIGO, advanced LIGO and Virgo. The bank is efficient to search for various compact binaries such as binary primordial black holes, binary neutron stars, binary black holes, as well as a mixed binary consisting of a non-spinning black hole and a neutron star.

gr-qc↗

arXiv2005

GEO600 Online Detector Characterization System

A world-wide network of interferometric gravitational wave detectors is currently operational. The detectors in the network are still in their commissioning phase and are expected to achieve their design sensitivity over the next year or so. Each detector is a complex instrument involving many subsystems and each subsystem is a source of noise at the output of the detector. Therefore, in addition to recording the main gravitational wave data channel at the output of the interferometer, the state of each detector subsystem is monitored and recorded. This subsidiary data is both large in volume as well as complex in nature. We require an online monitoring and analysis tool which can process all the data channels for various noise artefacts and summarize the results of the analysis in a manner that can be accessed and interpreted conveniently. In this paper we describe the GEO600 Online Detector Characterization System (GODCS), which is the tool that is being used to monitor the output of the GEO600 gravitational wave detector situated near Hannover in Germany. We describe the various algorithms that we use and how the results of several algorithms can be combined to make meaningful statements about the state of the detector. This paper will be useful to researchers in the area of gravitational wave astronomy as a record of the various analyses and checks carried out to ensure the quality and reliability of the data before searching the data for the presence of gravitational waves.

gr-qc↗