@article{9d88775ab785400d8e1332b579b8c6eb,
title = "Swift-BAT GUANO Follow-up of Gravitational-wave Triggers in the Third LIGO–Virgo–KAGRA Observing Run",
abstract = "We present results from a search for X-ray/gamma-ray counterparts of gravitational-wave (GW) candidates from the third observing run (O3) of the LIGO–Virgo–KAGRA network using the Swift Burst Alert Telescope (Swift-BAT). The search includes 636 GW candidates received with low latency, 86 of which have been confirmed by the offline analysis and included in the third cumulative Gravitational-Wave Transient Catalogs (GWTC-3). Targeted searches were carried out on the entire GW sample using the maximum-likelihood Non-imaging Transient Reconstruction and Temporal Search pipeline on the BAT data made available via the GUANO infrastructure. We do not detect any significant electromagnetic emission that is temporally and spatially coincident with any of the GW candidates. We report flux upper limits in the 15–350 keV band as a function of sky position for all the catalog candidates. For GW candidates where the Swift-BAT false alarm rate is less than 10−3 Hz, we compute the GW–BAT joint false alarm rate. Finally, the derived Swift-BAT upper limits are used to infer constraints on the putative electromagnetic emission associated with binary black hole mergers.",
keywords = "UKRI, STFC",
author = "{LIGO Scientific Collaboration} and {KAGRA Collaboration} and {Virgo Collaboration} and Gayathri Raman and Samuele Ronchini and James Delaunay and Aaron Tohuvavohu and Kennea, {Jamie A.} and Tyler Parsotan and Elena Ambrosi and Bernardini, {Maria Grazia} and Sergio Campana and Giancarlo Cusumano and Antonino D'A{\`i} and Paolo D'Avanzo and Valerio D'Elia and {De Pasquale}, Massimiliano and Simone Dichiara and Phil Evans and Dieter Hartmann and Paul Kuin and Andrea Melandri and Paul O{\textquoteright}Brien and Osborne, {Julian P.} and Kim Page and Palmer, {David M.} and Boris Sbarufatti and Gianpiero Tagliaferri and Eleonora Troja and Abac, {A. G.} and R. Abbott and H. Abe and I. Abouelfettouh and F. Acernese and K. Ackley and G. Ashton and {Cabourn Davies}, {G. S.} and O. Edy and Green, {S. M.} and Harry, {I. W.} and Hoy, {C. G.} and D. Keitel and K. Leyde and Lundgren, {A. P.} and R. Macas and C. McIsaac and S. Mozzon and Nuttall, {L. K.} and Tolley, {A. E.} and Weaving, {C. R.} and Williams, {M. J.} and Y. Yang and Y. Yang",
note = "Publisher Copyright: {\textcopyright} 2025. The Author(s). Published by the American Astronomical Society.",
year = "2025",
month = feb,
day = "20",
doi = "10.3847/1538-4357/ad9749",
language = "English",
volume = "980",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "American Astronomical Society",
number = "2",
}