{
  "abstract": "We analyse 17 years of Fermi-LAT $γ$-ray data toward the middle-aged supernova remnant (SNR) G156.2+05.7, supplemented by radio and CO observations and by published X-ray constraints. An extended $γ$-ray source is detected, well described by a 2D Gaussian template ($R_{68} \\sim 0.84^\\circ$). This description is preferred over a foreground CO template, whereas the Gaussian and a uniform disc are statistically indistinguishable under the AIC. The spectrum shows evidence for curvature, with a log-parabola preferred over a power law at the $\\approx 3.4σ$ level. Multi-wavelength spectral energy distribution (SED) modelling, under the adopted assumptions, suggests a leptonic--hadronic joint scenario consistent with the data, with the Fermi-LAT spectrum favouring a hadronic contribution over a purely leptonic interpretation. However, the proton-dominated alternative remains competitive, so the partition of the GeV emission is model-dependent. In the adopted leptonic--hadronic model, the electron population accounts for the radio synchrotron emission and a leptonic $γ$-ray component, while a steep proton population contributes the remaining hadronic $γ$-rays. Adopting a reference distance $d = 2.7$ kpc, the fitted electron cutoff ($E_{e,\\mathrm{cut}}\\approx 1.2$ TeV) is compatible with the thermal-dominated X-ray emission, while the proton cutoff is fixed by assumption at $1$ TeV. The northeast and southwest quadrants show enhanced $γ$-ray emission, which may be related to a clumpy or asymmetric surrounding medium. A correspondence with the directions of optical H$α$ filaments is suggested by the quadrant orientation but is not yet established. No significant long-term flux variability is found, consistent with steady emission from an extended source.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.04227",
  "author_total": 3,
  "authors": [
    {
      "name": "Wei-Liang Xu"
    },
    {
      "name": "Qing-Wen Tang"
    },
    {
      "name": "Long Li"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dgqybn9n2yb0y.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.04227",
  "fulltext_url": null,
  "id": "dgqybn9n2yb0y",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.04227",
  "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/2611.04227",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-03",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/dgqybn9n2yb0y.ris",
  "sources": [
    {
      "first_seen": "2026-11-04T15:21:25Z",
      "native_id": "2611.04227",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.04227"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    }
  ],
  "title": "Fermi-LAT Detection of Extended GeV Emission toward the Middle-aged Supernova Remnant G156.2+05.7",
  "title_text": "Fermi-LAT Detection of Extended GeV Emission toward the Middle-aged Supernova Remnant G156.2+05.7",
  "type": "preprint",
  "updated_at": "2026-11-06T18:21:01Z",
  "url": "https://research.draconitic.com/paper/dgqybn9n2yb0y",
  "venue": "arXiv",
  "versions": []
}