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

@article{abac2026gwtc40,
  title = {{GWTC-4.0: Updating the Gravitational-wave Transient Catalog with Observations from the First Part of the Fourth LIGO–Virgo–KAGRA Observing Run}},
  author = {Adrian Abac and I. Abouelfettouh and F. Acernese and K. Ackley and Christian Adamcewicz and S. Adhicary and D. Adhikari and N. Adhikari and R. X. Adhikari and V. K. Adkins and Samsuzzaman Afroz and A. Agapito and D. Agarwal and M. Agathos and Nancy Aggarwal and S. Aggarwal and Odylio D. Aguiar and I.-L. Ahrend and L. Aiello and A. Ain and P. Ajith and Sarp Akçay and Tomotada Akutsu and Simone Albanesi and W. Ali and S. Al-Kershi and C. Alléné and A. Allocca and S. Al-Shammari and P. A. Altin and S. Álvarez-López and W. Amar and O. Amarasinghe and A. Amato and F. Amicucci and Claude Amra and A. Ananyeva and S. B. Anderson and Warren G. Anderson and M. Andia and M. Ando and Marc Andrés-Carcasona and T. Andrić and J. Anglin and Stefano Ansoldi and Javier Mauricio Antelis and S. Antier and M. Aoumi and E. Z. Appavuravther and S. Appert and S. K. Apple and Koji Arai and A. Araya and M. C. Araya and Manuel Arca Sedda and J. S. Areeda and N. Aritomi and F. Armato and Sharon Armstrong and N. Arnaud},
  journal = {The Astrophysical Journal Letters},
  year = {2026},
  month = jun,
  doi = {10.3847/2041-8213/ae2c74},
  url = {https://doi.org/10.3847/2041-8213/ae2c74},
  note = {CC BY},
}

TY  - JOUR
TI  - GWTC-4.0: Updating the Gravitational-wave Transient Catalog with Observations from the First Part of the Fourth LIGO–Virgo–KAGRA Observing Run
AU  - Adrian Abac
AU  - I. Abouelfettouh
AU  - F. Acernese
AU  - K. Ackley
AU  - Christian Adamcewicz
AU  - S. Adhicary
AU  - D. Adhikari
AU  - N. Adhikari
AU  - R. X. Adhikari
AU  - V. K. Adkins
AU  - Samsuzzaman Afroz
AU  - A. Agapito
AU  - D. Agarwal
AU  - M. Agathos
AU  - Nancy Aggarwal
AU  - S. Aggarwal
AU  - Odylio D. Aguiar
AU  - I.-L. Ahrend
AU  - L. Aiello
AU  - A. Ain
AU  - P. Ajith
AU  - Sarp Akçay
AU  - Tomotada Akutsu
AU  - Simone Albanesi
AU  - W. Ali
AU  - S. Al-Kershi
AU  - C. Alléné
AU  - A. Allocca
AU  - S. Al-Shammari
AU  - P. A. Altin
AU  - S. Álvarez-López
AU  - W. Amar
AU  - O. Amarasinghe
AU  - A. Amato
AU  - F. Amicucci
AU  - Claude Amra
AU  - A. Ananyeva
AU  - S. B. Anderson
AU  - Warren G. Anderson
AU  - M. Andia
AU  - M. Ando
AU  - Marc Andrés-Carcasona
AU  - T. Andrić
AU  - J. Anglin
AU  - Stefano Ansoldi
AU  - Javier Mauricio Antelis
AU  - S. Antier
AU  - M. Aoumi
AU  - E. Z. Appavuravther
AU  - S. Appert
AU  - S. K. Apple
AU  - Koji Arai
AU  - A. Araya
AU  - M. C. Araya
AU  - Manuel Arca Sedda
AU  - J. S. Areeda
AU  - N. Aritomi
AU  - F. Armato
AU  - Sharon Armstrong
AU  - N. Arnaud
PY  - 2026
DA  - 2026/06/18
JO  - The Astrophysical Journal Letters
DO  - 10.3847/2041-8213/ae2c74
UR  - https://doi.org/10.3847/2041-8213/ae2c74
AB  - 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 these new data, we find 128 compact binary coalescence candidates that are identified by at least one of our search algorithms with a probability of astrophysical origin p astro ≥ 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 yr −1 . Based on the inferred component masses, these candidates are consistent with signals from binary black holes (BBHs) and neutron star–black hole binaries (GW230518_125908 and GW230529_181500). Median-inferred component masses of BBHs in the catalog now range from 5.79M⊙ (GW230627_015337) to 137 M ⊙ (GW231123_135430), while GW231123_135430 was probably produced by the most massive binary observed in the catalog. For the first time, we have discovered BBH signals with network signal-to-noise ratio exceeding 30, GW230814_230901 and GW231226_101520, 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 astro ≥ 0.5 and not otherwise vetoed, more than doubling the size of the catalog and further opening our view of the gravitational-wave Universe.
SN  - 2041-8205
SN  - 2041-8213
ER  -