{
  "abstract": "The recently discovered gravitational wave event GW231123 was interpreted as the merger of two black holes with a total mass of 190–265 M ⊙ , making it the heaviest such merger detected to date. While much of the postdiscovery literature has focused on its astrophysical origins, primary analyses have exhibited considerable discrepancies in the measurement of source properties between waveform models, which cannot reliably be reproduced by simulations. Such discrepancies may arise when an unaccounted overlapping signal is present in the data, or from phenomena that produce similar effects, such as gravitational lensing or overlapping noise artifacts. In this work, we analyze GW231123 using a flexible model that allows for two overlapping signals, and find that it is favored over the isolated signal model with Bayes factors of ∼10 2 –10 4 , depending on the waveform model. These values lie within the top few percent of the background distribution. Similar effects are not observed in GW190521, another high-mass event. Under the overlapping signals model, discrepancies in the measurement of source properties between waveform models are largely mitigated. We also find that neglecting an additional signal in overlapping-signal data can lead to discrepancies in the estimated source properties resembling those reported in GW231123. Although the overlapping signal model provides a higher Bayesian evidence, the astrophysical prior probability of two short signals overlapping is low. However, we find that the two recovered sources show similar properties. This, taken with the higher evidence of the two signal model, suggests that gravitational lensing may provide an alternative explanation.",
  "abstract_shown": true,
  "affiliations": [
    "University of Glasgow",
    "Nikhef—National Institute for Subatomic Physics",
    "Utrecht University",
    "Université Catholique de Louvain",
    "Royal Observatory of Belgium"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Qian Hu",
      "orcid": "0000-0002-3033-6491"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "Harsh Narola",
      "orcid": "0000-0001-9161-7919"
    },
    {
      "affs": [
        3
      ],
      "name": "Jef Heynen",
      "orcid": "0009-0007-5496-2159"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "M. Wright",
      "orcid": "0000-0003-1829-7482"
    },
    {
      "affs": [
        0
      ],
      "name": "John Veitch",
      "orcid": "0000-0002-6508-0713"
    },
    {
      "affs": [
        4,
        3
      ],
      "name": "Justin Janquart",
      "orcid": "0000-0003-2888-7152"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "Chris Van Den Broeck",
      "orcid": "0000-0001-6800-4006"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/14nj6xhcpfygt.bib",
  "cited_by": 7,
  "doi": "10.3847/1538-4357/ae6811",
  "fulltext_url": null,
  "id": "14nj6xhcpfygt",
  "issns": [
    "0004-637X",
    "1538-4357"
  ],
  "landing_url": "https://doi.org/10.3847/1538-4357/ae6811",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3103|Pulsars and Gravitational Waves Research"
    ]
  ],
  "openalex": "W7162450196",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-05-26",
  "publisher": "IOP Publishing",
  "ris": "https://research.draconitic.com/paper/14nj6xhcpfygt.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T13:26:43Z",
      "native_id": "W7162450196",
      "source": "openalex",
      "url": "https://doi.org/10.3847/1538-4357/ae6811"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Pulsars and Gravitational Waves Research",
      "subfield": "high-energy-astrophysics"
    }
  ],
  "title": "GW231123: Overlapping Gravitational Wave Signals?",
  "title_text": "GW231123: Overlapping Gravitational Wave Signals?",
  "type": "peer-reviewed",
  "updated_at": "2026-11-03T13:20:27Z",
  "url": "https://research.draconitic.com/paper/14nj6xhcpfygt",
  "venue": "The Astrophysical Journal",
  "versions": []
}