Date of Award
Doctor of Philosophy (PhD)
Peter R. Saulson
Physical Sciences and Mathematics
The first observing run of Advanced LIGO spanned 4 months, from September
12, 2015 to January 19, 2016, during which gravitational waves were directly detected
from two binary black hole systems, namely GW150914 and GW151226. Confident
detection of gravitational waves requires an understanding of instrumental noise transients
and artifacts that can reduce the sensitivity of a search for gravitational waves.
Studies of the quality of the detector data yield insights into the cause of instrumental
artifacts and data quality vetoes specific to a search are produced to mitigate the
effects of problematic data.
This dissertation provides an overview of the methods used to characterize noise
in the LIGO interferometers and provides examples of successful removal of transient
noise. The data set used in the first observing run is validated. Further, the systematic
removal of noisy data from analysis time is shown to improve the sensitivity of searches
for compact binary coalescences. The output of the PyCBC pipeline is used as a
metric for improvement.
The first direct detection of gravitational waves, GW150914, was a loud enough
signal that removing data with excess noise did not improve its significance. However,
the removal of data with excess noise decreased the false alarm rate of GW151226 by
a factor of 567, from 1 in 320 years (3.9 σ) to 1 in 183000 years (> 5.3 σ).
Massinger, Thomas James, "Detector Characterization for Advanced LIGO" (2016). Dissertations - ALL. 633.