{
  "abstract": "The binary neutron star merger GW170817 established a direct link between gravitational waves and short gamma-ray bursts (sGRBs), whose afterglows are commonly interpreted as nonthermal emission from structured relativistic jets viewed off-axis. Some sGRBs exhibit extended or plateau X-ray emission, suggesting prolonged central-engine activity. These X-ray photons can serve as seed photons for external inverse-Compton (EIC) scattering by relativistic electrons in the jet, producing very-high-energy (VHE) gamma rays. However, how the angular structure of the jet affects the detectability of EIC emission remains insufficiently explored. Here, we investigate EIC emission from off-axis structured jets and assess its detectability with the Cherenkov Telescope Array Observatory (CTAO). We find that EIC emission powered by extended and/or plateau X-rays produces detectable VHE signals from nearby sGRBs, particularly during the early afterglow, significantly outshining synchrotron self-Compton emission. In our adopted models, Gaussian and power-law jets produce brighter off-axis EIC emission than a top-hat jet, extending the viewing-angle range over which VHE emission may be detectable. These results demonstrate that early VHE observations with CTAO can probe both prolonged central-engine activity and the angular structure of relativistic jets in sGRBs.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.41476",
  "author_total": 3,
  "authors": [
    {
      "name": "Yuri Sato"
    },
    {
      "name": "Bing Theodore Zhang"
    },
    {
      "name": "Kohta Murase"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5g77emhmpef3t.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.41476",
  "fulltext_url": null,
  "id": "5g77emhmpef3t",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.41476",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.HE"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2610.41476",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5g77emhmpef3t.ris",
  "sources": [
    {
      "first_seen": "2026-11-02T12:21:15Z",
      "native_id": "2610.41476",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.41476"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    }
  ],
  "title": "Enhanced Detectability of Very-High-Energy Gamma Rays from Off-Axis Short Gamma-Ray Bursts: Impacts of Structured Jets and External Inverse-Compton Scattering",
  "title_text": "Enhanced Detectability of Very-High-Energy Gamma Rays from Off-Axis Short Gamma-Ray Bursts: Impacts of Structured Jets and External Inverse-Compton Scattering",
  "type": "preprint",
  "updated_at": "2026-11-04T15:20:51Z",
  "url": "https://research.draconitic.com/paper/5g77emhmpef3t",
  "venue": "arXiv",
  "versions": []
}