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General Relativity and Quantum Cosmology, gr-qc
Abstract:
Gravitational wave (GW) signals were recently detected directly by LIGO from
the coalescences of two stellar mass black hole pairs. These detections have
strengthened our long held belief that compact binary coalescences (CBCs) are
the most promising GW detection prospects accessible to ground-based
interferometric detectors. For detecting CBC signals it is of vital importance
to characterize and identify non-Gaussian and non-stationary noise in these
detectors. In this work we model two important classes of transient artifacts
that contribute to this noise and adversely affect the detector sensitivity to
CBC signals. One of them is the sine-Gaussian "glitch", characterized by a
central frequency $f_0$ and a quality factor $Q$ and the other is the chirping
sine-Gaussian glitch, which is characterized by $f_0$, $Q$ as well as a chirp
parameter. We study the response a bank of compact binary inspiral templates
has to these two families of glitches when they are used to match-filter data
containing any of these glitches. Two important characteristics of this
response are the distributions of the SNR and the time-lag of individual
templates. We show how these distributions differ from those when the detector
data has a real CBC signal instead of a glitch. We argue that these
distinctions can be utilized to develop useful signal-artifact discriminators
that add negligibly to the computational cost of a CBC search and can therefore
help improve the sensitivity of low-latency CBC searches. Specifically, we show
how the central frequency of a glitch can be used to set adaptive time-windows
around it so that any template trigger occurring in that window can be
quarantined for further vetting of its supposed astrophysical nature. Second,
we recommend focusing efforts on reducing the incidence of glitches with low
$f_0$ which makes it difficult to establish a causal connection between them.