{
  "abstract": "Gravitational-wave events from mergers of compact objects are a predicted source of high-energy neutrinos. Using data from the IceCube Neutrino Observatory, we search for neutrinos coincident with 85 significant and 945 low-significance gravitational-wave candidate events from compact binary coalescences published in real-time by the LIGO-Virgo-KAGRA collaboration during the first part of its fourth observing run (O4a) and its preceding engineering run, within a time window of $\\pm500$ seconds from the merger time. We report improvements to the online pipelines, including automatic sending of notices, which improved the median IceCube real-time response compared to the previous observing run by a factor of 2.7 times faster. In addition, we search for long-duration neutrino emission from three candidate events: two neutron star-black hole mergers and one low-significance gravitational-wave event with a possible subthreshold gamma-ray counterpart. We use two methods, both of which have been previously used to search for neutrinos from gravitational-wave transients: an unbinned maximum likelihood analysis on significant alerts and a Bayesian analysis accounting for astrophysical priors on all alerts. We find no statistically significant emission from any individual gravitational-wave event analyzed. In the unbinned maximum likelihood search, the lowest $p$-value event is S231029y, with $p=0.0079$ ($0.752$ post-trials). In the Bayesian search, the lowest $p$-value for significant events is S230904n, with $p=0.0076$ ($0.9996$ post-trials), and for low-significance events is S231025a, with $p=0.0011$ ($0.678$ post-trials), with an overall population $p$-value of $0.55$. We accordingly set upper limits for each event on the time-integrated flux and energy emitted in neutrinos, assuming isotropic emission.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2606.13762",
  "author_total": 421,
  "authors": [
    {
      "name": "The IceCube Collaboration"
    },
    {
      "name": "R. Abbasi"
    },
    {
      "name": "M. Ackermann"
    },
    {
      "name": "J. Adams"
    },
    {
      "name": "J. A. Aguilar"
    },
    {
      "name": "M. Ahlers"
    },
    {
      "name": "J. M. Alameddine"
    },
    {
      "name": "S. Ali"
    },
    {
      "name": "N. M. Amin"
    },
    {
      "name": "K. Andeen"
    },
    {
      "name": "C. Argüelles"
    },
    {
      "name": "Y. Ashida"
    },
    {
      "name": "S. Athanasiadou"
    },
    {
      "name": "S. N. Axani"
    },
    {
      "name": "R. Babu"
    },
    {
      "name": "X. Bai"
    },
    {
      "name": "A. Balagopal V."
    },
    {
      "name": "S. W. Barwick"
    },
    {
      "name": "V. Basu"
    },
    {
      "name": "R. Bay"
    },
    {
      "name": "J. J. Beatty"
    },
    {
      "name": "J. Becker Tjus"
    },
    {
      "name": "P. Behrens"
    },
    {
      "name": "J. Beise"
    },
    {
      "name": "C. Bellenghi"
    },
    {
      "name": "S. Benkel"
    },
    {
      "name": "S. BenZvi"
    },
    {
      "name": "D. Berley"
    },
    {
      "name": "E. Bernardini"
    },
    {
      "name": "D. Z. Besson"
    },
    {
      "name": "E. Blaufuss"
    },
    {
      "name": "L. Bloom"
    },
    {
      "name": "S. Blot"
    },
    {
      "name": "F. Bontempo"
    },
    {
      "name": "J. Y. Book Motzkin"
    },
    {
      "name": "C. Boscolo Meneguolo"
    },
    {
      "name": "S. Böser"
    },
    {
      "name": "O. Botner"
    },
    {
      "name": "J. Böttcher"
    },
    {
      "name": "J. Braun"
    },
    {
      "name": "B. Brinson"
    },
    {
      "name": "Z. Brisson-Tsavoussis"
    },
    {
      "name": "L. Brusa"
    },
    {
      "name": "R. T. Burley"
    },
    {
      "name": "D. Butterfield"
    },
    {
      "name": "K. Carloni"
    },
    {
      "name": "J. Carpio"
    },
    {
      "name": "N. Chau"
    },
    {
      "name": "Y. C. Chen"
    },
    {
      "name": "Z. Chen"
    },
    {
      "name": "D. Chirkin"
    },
    {
      "name": "S. Choi"
    },
    {
      "name": "A. Chubarov"
    },
    {
      "name": "B. A. Clark"
    },
    {
      "name": "G. H. Collin"
    },
    {
      "name": "D. A. Coloma Borja"
    },
    {
      "name": "A. Connolly"
    },
    {
      "name": "J. M. Conrad"
    },
    {
      "name": "D. F. Cowen"
    },
    {
      "name": "C. De Clercq"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cajxy13ykaaw2.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.13762",
  "fulltext_url": null,
  "id": "cajxy13ykaaw2",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.13762",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.HE"
    ],
    [
      "openalex",
      "3106|Astrophysics and Cosmic Phenomena"
    ]
  ],
  "openalex": "W7164837758",
  "pdf_url": "https://arxiv.org/pdf/2606.13762",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/cajxy13ykaaw2.ris",
  "sources": [
    {
      "first_seen": "2026-11-05T15:20:55Z",
      "native_id": "2606.13762",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.13762"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    }
  ],
  "title": "IceCube Real-time Searches for High-energy Neutrinos Coincident with LIGO/Virgo/KAGRA Gravitational-Wave Alerts in O4a",
  "title_text": "IceCube Real-time Searches for High-energy Neutrinos Coincident with LIGO/Virgo/KAGRA Gravitational-Wave Alerts in O4a",
  "type": "preprint",
  "updated_at": "2026-11-09T00:20:12Z",
  "url": "https://research.draconitic.com/paper/cajxy13ykaaw2",
  "venue": "arXiv",
  "versions": []
}