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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)
A seismic isolation system for the proposed 'Advanced LIGO' detector upgrade is under development. It consists of a two-stage in-vacuum active isolation platform that is supported by an external hydraulic actuation stage. A full-scale preliminary-design technology demonstrator of the in-vacuum platform has been assembled and is being tested at Stanford's(More)
We report on thermal noise from the internal friction of dielectric coatings made from alternating layers of Ta 2 O 5 and SiO 2 deposited on fused silica substrates. We present calculations of the thermal noise in gravitational wave interferometers due to optical coatings, when the material properties of the coating are different from those of the substrate(More)
To meet the overall isolation and alignment requirements for the optics in Advanced LIGO, the planned upgrade to LIGO, the US laser interferometric gravitational wave observatory, we are developing three subsystems: a hydraulic external pre-isolator for low frequency alignment and control, a two-stage active isolation platform designed to give a factor of(More)
Current interferometric gravitational wave detectors use test masses with mirror coatings formed from multiple layers of dielectric materials, most commonly alternating layers of SiO 2 (silica) and Ta 2 O 5 (tantala). However, mechanical loss in the Ta 2 O 5 /SiO 2 coatings may limit the design sensitivity for advanced detectors. We have investigated(More)
A stochastic background of gravitational waves is expected to arise from a superposition of a large number of unresolved gravitational-wave sources of astrophysical and cosmological origin. It should carry unique signatures from the earliest epochs in the evolution of the Universe, inaccessible to standard astrophysical observations. Direct measurements of(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)
Compact binary systems with neutron stars or black holes are one of the most promising sources for ground-based gravitational-wave detectors. Gravitational radiation encodes rich information about source physics; thus parameter estimation and model selection are crucial analysis steps for any detection candidate events. Detailed models of the anticipated(More)
(Affiliations can be found after the references in the electronic version) ABSTRACT Aims. A transient astrophysical event observed in both gravitational wave (GW) and electromagnetic (EM) channels would yield rich scientific rewards. A first program initiating EM follow-ups to possible transient GW events has been developed and exercised by the LIGO and(More)
This paper presents results of an all-sky search for periodic gravitational waves in the frequency range [50, 1 190] Hz and with frequency derivative range of ∼ [−20, 1.1] × 10 −10 Hz s −1 for the fifth LIGO science run (S5). The search uses a non-coherent Hough-transform method to combine the information from coherent searches on timescales of about one(More)