Adrian Abac, I. Abouelfettouh, F. Acernese, K. Ackley, S. Adhicary, D. Adhikari, N. Adhikari, R. X. Adhikari, V. K. Adkins, Samsuzzaman Afroz, D. Agarwal, M. Agathos, Maryam Aghaei Abchouyeh, O. D. Aguiar, Safoura Ahmadzadeh, L. Aiello, A. Ain, P. Ajith, S. Akcay, T. Akutsu, S. Albanesi, R. A. Alfaidi, A. Al-Jodah, C. Alléné, A. Allocca, S. Al-Shammari, P. A. Altin, S. Álvarez-López, O. Amarasinghe, A. Amato, Claude Amra, A. Ananyeva, S. B. Anderson, W. G. Anderson, M. Andia, M. Ando, Tomás Andrade, M. Andrés-Carcasona, T. Andrić, J. D. Anglin, S. Ansoldi, Javier M. Antelis, S. Antier, M. Aoumi, E. Z. Appavuravther, S. Appert, S. K. Apple, K. Arai, A. Araya, M. C. Araya, Manuel Arca Sedda, J. S. Areeda, L Argianas, N. Aritomi, F. Armato, Shiro Armstrong, N. Arnaud, M. Arogeti, Scott Aronson, G. Ashton, Y. Aso, M. Assiduo, S. Assis de Souza Melo, S. M. Aston, P. Astone, F. Attadio, F. Aubin, K. AultONeal, Gianluca Avallone, S. Babak, F. Badaracco, C. Badger, S. Bae, S. Bagnasco, E. Bagui, L. Baiotti, R. Bajpai, T. Baka, Tessa Baker, M. Ball, G. Ballardin, S. W. Ballmer, S. Banagiri, B. Banerjee, D. Bankar, T. M. Baptiste, Pratyusava Baral, J. C. Barayoga, B. C. Barish, D. Barker, Nilkanta Barman, P. Barneo, F. Barone, B. Barr, L. Barsotti, M. Barsuglia, D. Barta, Alice Bartoletti, M. A. Barton, I. Bartos
Abstract The Gravitational-Wave Transient Catalog (GWTC) is a collection of candidate gravitational-wave transient signals identified and characterized by the LIGO–Virgo–KAGRA Collaboration. Producing the contents of the GWTC from detector data requires complex analysis methods. These comprise techniques to model the signal; identify the transients in the data; evaluate the quality of the data and mitigate possible instrumental issues; infer the parameters of each transient; compare the data with the waveform models for compact binary coalescences; and handle the large amount of results associated with all of these different analyses. In this paper, we describe the methods employed to produce the catalog’s fourth release, GWTC-4.0, focusing on the analysis of the first part of the fourth observing run of Advanced LIGO, Advanced Virgo and KAGRA.