S. M. Aston

TL;DR: The results of targeted searches for gravitational-wave transients associated with gamma-ray bursts during the second observing run of Advanced LIGO and Advanced Virgo, which took place from 2016 November to 2017 August, were presented in this paper.

TL;DR: In this article, the authors reported results from searches for anisotropic stochastic gravitational-wave backgrounds using data from the first three observing runs of the Advanced LIGO and Advanced Virgo detectors.

TL;DR: In this paper, a hydraulic external pre-isolator for low frequency alignment and control, a two-stage active isolation platform designed to give a factor of ~1000 attenuation at 10 Hz, and a multiple pendulum suspension system that provides passive isolation above a few hertz.

Abstract: We report on a comprehensive all-sky search for periodic gravitational waves in the frequency band 100-1500 Hz and with a frequency time derivative in the range of $[-1.18, +1.00]\times 10^{-8}$ Hz/s. Such a signal could be produced by a nearby spinning and slightly non-axisymmetric isolated neutron star in our galaxy. This search uses the data from the Initial LIGO sixth science run and covers a larger parameter space with respect to any past search. A Loosely Coherent detection pipeline was applied to follow up weak outliers in both Gaussian (95% recovery rate) and non-Gaussian (75% recovery rate) bands. No gravitational wave signals were observed, and upper limits were placed on their strength. Our smallest upper limit on worst-case (linearly polarized) strain amplitude $h_0$ is ${9.7}\times 10^{-25}$ near 169 Hz, while at the high end of our frequency range we achieve a worst-case upper limit of ${5.5}\times 10^{-24}$. Both cases refer to all sky locations and entire range of frequency derivative values.

TL;DR: In this article, the first low frequency all-sky search of continuous gravitational wave signals was conducted on Virgo VSR2 and VSR4 data and the results of the search covered the full sky, a frequency range between 20 and 128 Hz with a range of spin-down between -1.0×10-10 and +1.5×10 -11 Hz/s.