GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo During the Second Part of the Third Observing Run — Data Quality Products for GW Searches

This material is part of several data products associated with GWTC-3, the third Gravitational-Wave Transient Catalog from the LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration. For more information, see the paper (dcc.ligo.org/LIGO-P2000318/public), the related material linked from this page, and the GWTC-3 data release documentation (www.gw-openscience.org/GWTC-3/).

This release contains two data-quality products that are used by search analyses to help mitigate non-Gaussian noise in the detector data. Gating removes short-duration artifacts from the data by smoothly rolling the affected data to zero. The iDQ glitch likelihood uses machine learning to predict the probability that a non-Gaussian transient is present using information from auxiliary channels.

Gating files used in analyses of O3 LIGO data

As a pre-processing step, the PyCBC search pipeline uses an inverted-Tukey window to mitigate the effect of loud, non-Gaussian features in the data. This is further described in Usman et al. 2016.

A subset of these times are the times listed in the txt files

• H1-O3_GATES_1238166018-31197600.txt
• L1-O3_GATES_1238166018-31197600.txt

These times in these files were chosen based on auxiliary monitors of overflows in the digital-to-analog converters used to control the positions of the test masses. The gated times (i.e. the time period where the data is zeroed) are time segments where these monitors recorded an overflow were. The central time and suggested half-width of zero time were chosen to fully cover these time seconds. The final gating parameter, the suggested taper time was chosen to be 0.5 to balance the cost of impacting more data with the window function versus introducing additional artifacts into the data.

The syntax of the files themselves is

central time suggested half-width of zero time suggested taper time

with each row containing the parameters of a single gate.

The included notebook provides an example of how to read in and apply one of the suggested gates.

Renormalized iDQ timeseries

The renormalized iDQ timeseries data-quality product is used within the GstLAL search pipeline to generate results for GWTC-3. This data product was found to be statistically helpful in improving data quality within the GstLAL search pipeline. This is further described in <a