843 research outputs found
Second Einstein Telescope Mock Science Challenge : Detection of the GW Stochastic Background from Compact Binary Coalescences
We present the results of the search for an astrophysical gravitational-wave
stochastic background during the second Einstein Telescope mock data and
science challenge. Assuming that the loudest sources can be detected
individually and removed from the data, we show that the residual background
can be recovered with an accuracy of with the standard cross-correlation
statistic, after correction of a systematic bias due to the non-isotropy of the
sources.Comment: 15 pages, 4 figures, accepted for publication in Physical Review
Design and fabrication of prototype system for early warning of impending bearing failure
A test program was conducted with the objective of developing a method and equipment for on-line monitoring of installed ball bearings to detect deterioration or impending failure of the bearings. The program was directed at the spin-axis bearings of a control moment gyro. The bearings were tested at speeds of 6000 and 8000 rpm, thrust loads from 50 to 1000 pounds, with a wide range of lubrication conditions, with and without a simulated fatigue spall implanted in the inner race ball track. It was concluded that a bearing monitor system based on detection and analysis of modulations of a fault indicating bearing resonance frequency can provide a low threshold of sensitivity
Report on the OAS General Assembly in Antigua, Guatemala
The APPG for Drug Policy Reform were invited by President Otto Perez Molina of Guatemala to attend the 43rd General Assembly of the OAS from 4-6 June, as Observers. This report represents my reflections on the meeting
Application of a Zero-latency Whitening Filter to Compact Binary Coalescence Gravitational-wave Searches
Joint electromagnetic and gravitational-wave (GW) observation is a major goal
of both the GW astronomy and electromagnetic astronomy communities for the
coming decade. One way to accomplish this goal is to direct follow-up of GW
candidates. Prompt electromagnetic emission may fade quickly, therefore it is
desirable to have GW detection happen as quickly as possible. A leading source
of latency in GW detection is the whitening of the data. We examine the
performance of a zero-latency whitening filter in a detection pipeline for
compact binary coalescence (CBC) GW signals. We find that the filter reproduces
signal-to-noise ratio (SNR) sufficiently consistent with the results of the
original high-latency and phase-preserving filter for both noise and artificial
GW signals (called "injections"). Additionally, we demonstrate that these two
whitening filters show excellent agreement in value, a discriminator
for GW signals.Comment: 8 pages, 12 figure
A Mock Data and Science Challenge for Detecting an Astrophysical Stochastic Gravitational-Wave Background with Advanced LIGO and Advanced Virgo
The purpose of this mock data and science challenge is to prepare the data
analysis and science interpretation for the second generation of
gravitational-wave experiments Advanced LIGO-Virgo in the search for a
stochastic gravitational-wave background signal of astrophysical origin. Here
we present a series of signal and data challenges, with increasing complexity,
whose aim is to test the ability of current data analysis pipelines at
detecting an astrophysically produced gravitational-wave background, test
parameter estimation methods and interpret the results. We introduce the
production of these mock data sets that includes a realistic observing scenario
data set where we account for different sensitivities of the advanced detectors
as they are continuously upgraded toward their design sensitivity. After
analysing these with the standard isotropic cross-correlation pipeline we find
that we are able to recover the injected gravitational-wave background energy
density to within for all of the data sets and present the results
from the parameter estimation. The results from this mock data and science
challenge show that advanced LIGO and Virgo will be ready and able to make a
detection of an astrophysical gravitational-wave background within a few years
of operations of the advanced detectors, given a high enough rate of compact
binary coalescing events
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