[Paper Review] GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo During the Second Part of the Third Observing Run

The LIGO Scientific Collaboration, The Virgo Collaboration+1660 more|Open Repository and Bibliography (University of Liège)|Nov 5, 2021

Pulsars and Gravitational Waves Research61 citations

TL;DR

This paper presents the GWTC-3 catalog of compact binary coalescences observed by LIGO and Virgo during the second part of the third observing run, detailing detections and source properties.

ABSTRACT

The third Gravitational-Wave Transient Catalog (GWTC-3) describes signals detected with Advanced LIGO and Advanced Virgo up to the end of their third observing run. Updating the previous GWTC-2.1, we present candidate gravitational waves from compact binary coalescences during the second half of the third observing run (O3b) between 1 November 2019, 15:00 UTC and 27 March 2020, 17:00 UTC. There are 35 compact binary coalescence candidates identified by at least one of our search algorithms with a probability of astrophysical origin $p_\mathrm{astro} > 0.5$. Of these, 18 were previously reported as low-latency public alerts, and 17 are reported here for the first time. Based upon estimates for the component masses, our O3b candidates with $p_\mathrm{astro} > 0.5$ are consistent with gravitational-wave signals from binary black holes or neutron star-black hole binaries, and we identify none from binary neutron stars. However, from the gravitational-wave data alone, we are not able to measure matter effects that distinguish whether the binary components are neutron stars or black holes. The range of inferred component masses is similar to that found with previous catalogs, but the O3b candidates include the first confident observations of neutron star-black hole binaries. Including the 35 candidates from O3b in addition to those from GWTC-2.1, GWTC-3 contains 90 candidates found by our analysis with $p_\mathrm{astro} > 0.5$ across the first three observing runs. These observations of compact binary coalescences present an unprecedented view of the properties of black holes and neutron stars.

Motivation & Objective

• Present a catalog of compact binary coalescence detections from the second part of the third observing run.
• Characterize the source properties and inference results for detected events.
• Summarize detection methodologies, data quality, and statistical considerations.
• Provide updated merger-rate estimates and population inferences based on the updated catalog.

Proposed method

• Compile and vet observations from LIGO and Virgo during the specified observing period.
• Identify and classify compact binary coalescence events.
• Infer source parameters such as masses and spins from the gravitational-wave signals.
• Quantify uncertainties and perform population-level analyses for rates and distributions.
• Apply statistical methods to construct a comprehensive catalog of events.

Experimental results

Research questions

• RQ1 What are the compact binary coalescence events detected in the second part of the third observing run?
• RQ2 What are the inferred source-property distributions (e.g., masses, spins) for these events?
• RQ3 What are the implications for merger-rate densities and population properties based on GWTC-3?

Key findings

• A catalog of compact binary coalescence detections reported by LIGO and Virgo during the second part of the third observing run.
• Inferred source properties and their uncertainties for the detected events are summarized in the catalog.
• Population-level implications such as merger-rate estimates are updated based on GWTC-3.