{
  "abstract": "We present photometric and spectroscopic follow-up observations of the strongly-lensed H-poor superluminous supernova (SLSN) 2025wny at $z = 2.0155$. We use integral-field Keck-II/KCWI spectroscopy to obtain rest-frame ultraviolet spectra spanning $11$ to $61$ days after maximum light. We use Pan-STARRS photometry to constrain the brightest image's magnification, finding $μ_A=19.4\\pm1.6$, a factor of $\\sim$2-4 higher than mass-modeling estimates. We fit the Pan-STARRS photometry with a magnetar energy-injection model including $^{56}$Ni decay using the Modular Open Source Fitter for Transients (MOSFiT); the model can reproduce the near-maximum light curve with parameters typical of local universe SLSNe-I, including a magnetar spin period $P_{\\rm spin}=4.1^{+0.7}_{-1.0}\\,\\mathrm{ms}$ and magnetic field $B_{\\perp}=2.4^{+1.1}_{-0.8}\\times10^{14}\\,\\mathrm{G}$; however, the late-time plateau suggests an additional power source. Spectroscopically, iron-group element line blanketing is virtually absent in the rest-frame UV spectra, and the absorption features match previously identified SLSN-I features from abundance tomography. Based on narrow ISM line metallicity estimates, SN 2025wny exploded in a sub-solar-metallicity galaxy. From host-galaxy lines in our rest-frame UV-to-optical spectrum we estimate high-velocity outflows of $\\sim$575 km s$^{-1}$ and an exceptionally high Ly$α$ escape fraction of $f_{esc}^{Lyα}=0.23\\pm0.03$. SN 2025wny matches lower-redshift SLSNe reasonably well. Upcoming surveys like LSST and Roman will discover additional high-redshift SLSNe, further testing whether SLSNe-I explosions remain consistent at the population level in the early universe.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.08903",
  "author_total": 29,
  "authors": [
    {
      "name": "Willem B. Hoogendam"
    },
    {
      "name": "David O. Jones"
    },
    {
      "name": "Christopher J. Storfer"
    },
    {
      "name": "Luca Izzo"
    },
    {
      "name": "Kyle W. Davis"
    },
    {
      "name": "Miranda Y. Kong"
    },
    {
      "name": "Katie Auchettl"
    },
    {
      "name": "Aadya Agrawal"
    },
    {
      "name": "David R. Aguilera-Dena"
    },
    {
      "name": "Kenneth C. Chambers"
    },
    {
      "name": "Siyuan Chen"
    },
    {
      "name": "Thomas de Boer"
    },
    {
      "name": "Ryan J. Foley"
    },
    {
      "name": "Matthew Grayling"
    },
    {
      "name": "Jason T. Hinkle"
    },
    {
      "name": "Jens Hjorth"
    },
    {
      "name": "Mark E. Huber"
    },
    {
      "name": "Chien-Cheng Lin"
    },
    {
      "name": "Thomas B. Lowe"
    },
    {
      "name": "Eugene A. Magnier"
    },
    {
      "name": "Kaisey S. Mandel"
    },
    {
      "name": "C. Tanner Murphey"
    },
    {
      "name": "Gautham Narayan"
    },
    {
      "name": "Gregory S. H. Paek"
    },
    {
      "name": "Kishore C. Patra"
    },
    {
      "name": "Haille M. L. Perkins"
    },
    {
      "name": "Armin Rest"
    },
    {
      "name": "Benjamin J. Shappee"
    },
    {
      "name": "Richard J. Wainscoat"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fzyk67231073r.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.08903",
  "fulltext_url": null,
  "id": "fzyk67231073r",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.08903",
  "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.GA"
    ],
    [
      "arxiv",
      "astro-ph.HE"
    ],
    [
      "arxiv",
      "astro-ph.SR"
    ],
    [
      "openalex",
      "3103|Gamma-ray bursts and supernovae"
    ]
  ],
  "openalex": "W7220948019",
  "pdf_url": "https://arxiv.org/pdf/2610.08903",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-06",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/fzyk67231073r.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:37Z",
      "native_id": "2610.08903",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.08903"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.SR",
      "subfield": "stellar"
    }
  ],
  "title": "Extreme Stellar Death and Galaxy Feedback at z = 2: A Rest-frame Ultraviolet Characterization of the Strongly Lensed Superluminous Supernova 2025wny",
  "title_text": "Extreme Stellar Death and Galaxy Feedback at z = 2: A Rest-frame Ultraviolet Characterization of the Strongly Lensed Superluminous Supernova 2025wny",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:37Z",
  "url": "https://research.draconitic.com/paper/fzyk67231073r",
  "venue": "arXiv",
  "versions": []
}