TITLE: GCN CIRCULAR NUMBER: 18626 SUBJECT: LIGO/Virgo G194575: Updated significance from offline GW analysis DATE: 15/11/20 13:33:17 GMT FROM: Leo Singer at NASA/GSFC The LIGO Scientific Collaboration and Virgo report: The routine offline compact binary coalescence (CBC) analysis of the span of data containing the gravitational-wave candidate G194575 (GCN 18442) has completed. The offline CBC analysis consists of a pair of matched filter search pipelines, gstlal and pycbc. They are similar to the low-latency CBC searches that generate real-time alerts, but analyze the data in discrete two-week chunks, are sensitive to both neutron star and black hole binary mergers, use additional data quality vetoes, and employ more live time to estimate the significance of candidates. In our initial circular, we had reported the false alarm rate (FAR) estimated by the low-latency gstlal search, 9.654e-08, or about 1/120 days. As estimated by the offline gstlal search, the candidate has a FAR of 5.87e-06 Hz, or 1/1.97 days. As estimated by the offline pycbc search, G194575 has a FAR of 8.19e-6 Hz, or 1/1.41 days. Though the low-latency FAR estimate for this event met our threshold for distribution of an alert, from the offline analysis we conclude that G194575 is no longer an event of interest.