On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the… (More)
Modern scientific experiments acquire large amounts of data that must be analyzed in subtle and complicated ways to extract the best results. The Laser Interferometer Gravitational Wave Observatory (LIGO) is an ambitious effort to detect gravitational waves produced by violent events in the universe, such as the collision of two black holes or the explosion… (More)
We report on a search for gravitational waves from binary black hole inspirals in the data from the second science run of the LIGO interferometers. The search focused on binary systems with component masses between 3 and 20M. Optimally oriented binaries with distances up to 1 Mpc could be detected with efficiency of at least 90%. We found no events that… (More)
GRASP (Gravitational Radiation Analysis & Simulation Package) is a public-domain software tool-kit designed for analysis and simulation of data from gravitational wave detectors. This users manual describes the use and features of this package.
We present upper limits on the gravitational wave emission from 78 radio pulsars based on data from the third and fourth science runs of the LIGO and GEO 600 gravitational wave detectors. The data from both runs have been combined coherently to maximise sensitivity. For the first time pulsars within binary (or multiple) systems have been included in the… (More)
Homothetic scalar field collapse is considered in this article. By making a suitable choice of variables the equations are reduced to an autonomous system. Then using a combination of numerical and analytic techniques it is shown that there are two classes of solutions. The first consists of solutions with a non-singular origin in which the scalar field… (More)
We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter… (More)
We searched for an anisotropic background of gravitational waves using data from the LIGO S4 science run and a method that is optimized for point sources. This is appropriate if, for example, the gravitational wave background is dominated by a small number of distinct astrophysical sources. No signal was seen. Upper limit maps were produced assuming two… (More)