{
  "abstract": "We present the discovery of EP250827b/SN 2025wkm, an X-ray flash (XRF) discovered by the Einstein Probe (EP), accompanied by a broad-line Type Ic supernova (SN Ic-BL) at z = 0.1194. EP250827b possesses a prompt X-ray luminosity of ∼10 45 erg s −1 , lasts over 1000 s, and has a peak energy E p < 1.5 keV at 90% confidence. SN 2025wkm possesses a double-peaked optical light curve (LC), though its bolometric luminosity plateaus after its initial peak for ∼20 days, consistent with a central engine injecting additional energy into the explosion. Its spectrum transitions from a blue to red continuum with clear blueshifted broad absorption features consistent with a SN Ic-BL classification. We do not detect any transient radio emission and rule out the existence of an on-axis, energetic jet ≳10 50 erg assuming a typical LGRB circumburst constant density ( n ≈ 10 −3 –10 −1 cm −3 ) and microphysical parameters ( ϵ e = 0.1 and ϵ B = 0.01). In the model we invoke, the collapse gives rise to a long-lived magnetar, potentially surrounded by an accretion disk. Magnetically driven winds from the magnetar and the disk mix together and break out with a velocity ∼0.35 c and interact with an extended circumstellar medium with radius ∼10 13 cm, generating X-ray breakout emission through nonthermal free–free processes. The disk outflows and magnetar winds power blackbody photospheric emission as they cool adiabatically and thermalize, producing the first SN peak. The spin-down luminosity of the magnetar and radioactive decay of 56 Ni power the late-time emission. We end by discussing the landscape of XRF-SNe within the context of EP’s recent discoveries.",
  "abstract_shown": true,
  "affiliations": [
    "California Institute of Technology",
    "NASA Goddard Space Flight Center",
    "University of Maryland",
    "Chinese Academy of Sciences",
    "Carnegie Mellon University",
    "Columbia University",
    "Department of Physics and Kavli Institute for Astrophysics and Space Research",
    "Flatiron Institute",
    "Cornell University",
    "Beijing Normal University",
    "University of Chinese Academy of Sciences",
    "Cerro Tololo Inter-American Observatory/NSF NOIRLab",
    "Center for Nonlinear Studies",
    "Department of Physics & Astronomy",
    "Altay Astronomical Observatory",
    "INAF-Osservatorio Astronomico di Brera",
    "Radboud University",
    "Liverpool John Moores University",
    "Louisiana State University",
    "Stockholm University",
    "University of Cambridge",
    "The Observatories of the Carnegie Institution for Science",
    "National Central University",
    "Shanghai Astronomical Observatory",
    "Las Cumbres Observatory",
    "University Observatory",
    "University of Washington",
    "Excellence Cluster ORIGINS",
    "National Astronomical Research Institute of Thailand",
    "Instituto de Astrofísica de Andalucía (IAA-CSIC)",
    "Universidad de Málaga",
    "University of California",
    "Huazhong University of Science and Technology",
    "Cosmic Dawn Center (DAWN)",
    "University of Copenhagen",
    "Space Telescope Science Institute",
    "University of Helsinki",
    "Guanxi University",
    "National Astronomical Observatory of Japan",
    "University of Science and Technology of China"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 100,
  "authors": [
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        1,
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      "name": "Gokul P. Srinivasaragavan",
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        3
      ],
      "name": "Dongyue Li",
      "orcid": "0000-0002-4562-7179"
    },
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      "affs": [
        4
      ],
      "name": "Xander J. Hall",
      "orcid": "0000-0002-9364-5419"
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      "affs": [
        5,
        6,
        7
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      "name": "Ore Gottlieb",
      "orcid": "0000-0003-3115-2456"
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      ],
      "name": "Genevieve Schroeder",
      "orcid": "0000-0001-9915-8147"
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    {
      "affs": [
        3
      ],
      "name": "He‐Yang Liu",
      "orcid": "0000-0002-2412-5751"
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    {
      "affs": [
        4
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      "name": "Brendan O’Connor",
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      "name": "Chichuan Jin",
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        0
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      "name": "M. M. Kasliwal",
      "orcid": "0000-0002-5619-4938"
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        11
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      "name": "Tomás Ahumada",
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      "name": "Qinyu Wu",
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      "name": "Chris L. Fryer",
      "orcid": "0000-0003-2624-0056"
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      "name": "Annabelle E. Niblett",
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      "name": "Dong Xu",
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      "name": "Maria Edvige Ravasio",
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      "name": "Grace Daja",
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      "name": "Shreya Anand",
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      "name": "Anna Y. Q. Ho",
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      "name": "Hui Sun",
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      "name": "Daniel A. Perley",
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      "name": "Yan Lin",
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      "name": "Eric Burns",
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      "name": "S. B. Cenko",
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      "name": "J. Sollerman",
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      "name": "Nikhil Sarin",
      "orcid": "0000-0003-2700-1030"
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      "name": "Anthony L. Piro",
      "orcid": "0000-0001-6806-0673"
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        22
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      "name": "Amar Aryan",
      "orcid": "0000-0002-9928-0369"
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      "name": "M. Coleman Miller",
      "orcid": "0000-0002-2666-728X"
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      "name": "Jie An",
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      "name": "Tao An",
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      "name": "Moira Andrews",
      "orcid": "0000-0002-1895-6639"
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      "name": "Jule Augustin",
      "orcid": "0009-0002-6662-4900"
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        26
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      "name": "Eric C. Bellm",
      "orcid": "0000-0001-8018-5348"
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        17
      ],
      "name": "Aleksandra Bochenek",
      "orcid": "0009-0008-2714-2507"
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      ],
      "name": "Malte Busmann",
      "orcid": "0009-0001-0574-2332"
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    {
      "affs": [
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      ],
      "name": "Krittapas Chanchaiworawit",
      "orcid": "0000-0002-9650-4371"
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    {
      "affs": [
        3
      ],
      "name": "Huaqing Cheng"
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    {
      "affs": [
        29
      ],
      "name": "M. D. Caballero‐García",
      "orcid": "0000-0001-7920-4564"
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    {
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        29,
        30
      ],
      "name": "Alberto J. Castro-Tirado",
      "orcid": "0000-0003-2999-3563"
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        3,
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      ],
      "name": "Ali Esamdin",
      "orcid": "0000-0003-1845-4900"
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      "name": "Jennifer Fabà-Moreno",
      "orcid": "0009-0006-7670-9843"
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      "name": "Joseph Farah",
      "orcid": "0000-0003-4914-5625"
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      "name": "Emilio Fernández-García",
      "orcid": "0009-0009-4604-9639"
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        32
      ],
      "name": "Shao-Yu Fu",
      "orcid": "0009-0002-7730-3985"
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      "affs": [
        33,
        34
      ],
      "name": "J. P. U. Fynbo",
      "orcid": "0000-0002-8149-8298"
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        25
      ],
      "name": "Julius Gassert",
      "orcid": "0009-0008-2754-1946"
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    {
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        35
      ],
      "name": "Estefania Padilla Gonzalez",
      "orcid": "0000-0003-0209-9246"
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      "name": "Ignacio Pérez-García",
      "orcid": "0000-0002-7273-3671"
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        0
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      "name": "M. J. Graham",
      "orcid": "0000-0002-3168-0139"
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      "name": "Maria I. Gritsevich",
      "orcid": "0000-0003-4268-6277"
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      "name": "Daniel Gruen",
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      "name": "Sergiy Guziy",
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      "name": "He Lp",
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      "name": "D. Andrew Howell",
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      "name": "Jingwei Hu"
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      "name": "Y. D. Hu",
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      "name": "Joahan Castaneda Jaimes",
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      "name": "Ji-an Jiang",
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  "bibtex": "https://research.draconitic.com/paper/4xzm1pvv5krxj.bib",
  "cited_by": 18,
  "doi": "10.3847/2041-8213/ae7a68",
  "fulltext_url": null,
  "id": "4xzm1pvv5krxj",
  "issns": [
    "2041-8205",
    "2041-8213"
  ],
  "landing_url": "https://doi.org/10.3847/2041-8213/ae7a68",
  "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": [
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      "openalex",
      "3103|Gamma-ray bursts and supernovae"
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  "openalex": "W4417295233",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-07-22",
  "publisher": "IOP Publishing",
  "ris": "https://research.draconitic.com/paper/4xzm1pvv5krxj.ris",
  "sources": [
    {
      "first_seen": "2026-11-07T13:20:45Z",
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      "url": "https://doi.org/10.3847/2041-8213/ae7a68"
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  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Gamma-ray bursts and supernovae",
      "subfield": "high-energy-astrophysics"
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  ],
  "title": "EP250827b/SN 2025wkm: An X-Ray Flash-supernova Powered by a Central Engine and Circumstellar Interaction",
  "title_text": "EP250827b/SN 2025wkm: An X-Ray Flash-supernova Powered by a Central Engine and Circumstellar Interaction",
  "type": "peer-reviewed",
  "updated_at": "2026-11-07T13:20:45Z",
  "url": "https://research.draconitic.com/paper/4xzm1pvv5krxj",
  "venue": "The Astrophysical Journal Letters",
  "versions": []
}