GWTC-4.0: Updating the Gravitational-Wave Transient Catalog with Observations from the First Part of the Fourth LIGO-Virgo-KAGRA Observing Run

TL;DR

The GWTC-4.0 catalog updates gravitational-wave detections from the first part of the fourth LIGO-Virgo-KAGRA observing run, adding 128 new candidates and detailed source properties, significantly expanding our understanding of compact binary mergers.

Contribution

This paper presents the first comprehensive catalog update with new gravitational-wave candidates from O4a, including detailed source measurements and the discovery of high SNR binary black hole signals.

Findings

128 new candidates with p_astro ≥ 0.5

Binary black hole component masses range from 5.79 to 137 solar masses

Discovery of binary black hole signals with SNR > 30

Abstract

Version 4.0 of the Gravitational-Wave Transient Catalog (GWTC-4.0) adds new candidates detected by the LIGO, Virgo, and KAGRA observatories through the first part of the fourth observing run (O4a: 2023 May 24 15:00:00 to 2024 January 16 16:00:00 UTC) and a preceding engineering run. In this new data, we find 128 new compact binary coalescence candidates that are identified by at least one of our search algorithms with a probability of astrophysical origin $p_{\rm astro} \geq 0.5$ and that are not vetoed during event validation. We also provide detailed source property measurements for 86 of these that have a false alarm rate $< 1 \rm{yr}^{-1}$. Based on the inferred component masses, these new candidates are consistent with signals from binary black holes and neutron star-black hole binaries (GW230518_125908 and GW230529_181500). Median inferred component masses of binary black holes in the catalog now range from $5.79\,M_\odot$ (GW230627_015337) to $137\,M_\odot$ (GW231123_135430), while GW231123_135430 was probably produced by the most massive binary observed in the catalog. For the first time we have discovered binary black hole signals with network signal-to-noise ratio exceeding 30, GW230814_230901 and GW231226_01520, enabling high-fidelity studies of the waveforms and astrophysical properties of these systems. Combined with the 90 candidates included in GWTC-3.0, the catalog now contains 218 candidates with $p_{\rm astro} \geq 0.5$ and not otherwise vetoed, doubling the size of the catalog and further opening our view of the gravitational-wave Universe.