Extreme Stellar Death and Galaxy Feedback at z = 2: A Rest-frame Ultraviolet Characterization of the Strongly Lensed Superluminous Supernova 2025wny

@misc{hoogendam2026extreme,
  title = {{Extreme Stellar Death and Galaxy Feedback at z = 2: A Rest-frame Ultraviolet Characterization of the Strongly Lensed Superluminous Supernova 2025wny}},
  author = {Willem B. Hoogendam and David O. Jones and Christopher J. Storfer and Luca Izzo and Kyle W. Davis and Miranda Y. Kong and Katie Auchettl and Aadya Agrawal and David R. Aguilera-Dena and Kenneth C. Chambers and Siyuan Chen and Thomas de Boer and Ryan J. Foley and Matthew Grayling and Jason T. Hinkle and Jens Hjorth and Mark E. Huber and Chien-Cheng Lin and Thomas B. Lowe and Eugene A. Magnier and Kaisey S. Mandel and C. Tanner Murphey and Gautham Narayan and Gregory S. H. Paek and Kishore C. Patra and Haille M. L. Perkins and Armin Rest and Benjamin J. Shappee and Richard J. Wainscoat},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.08903},
  eprint = {2610.08903},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.08903},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Extreme Stellar Death and Galaxy Feedback at z = 2: A Rest-frame Ultraviolet Characterization of the Strongly Lensed Superluminous Supernova 2025wny
AU  - Willem B. Hoogendam
AU  - David O. Jones
AU  - Christopher J. Storfer
AU  - Luca Izzo
AU  - Kyle W. Davis
AU  - Miranda Y. Kong
AU  - Katie Auchettl
AU  - Aadya Agrawal
AU  - David R. Aguilera-Dena
AU  - Kenneth C. Chambers
AU  - Siyuan Chen
AU  - Thomas de Boer
AU  - Ryan J. Foley
AU  - Matthew Grayling
AU  - Jason T. Hinkle
AU  - Jens Hjorth
AU  - Mark E. Huber
AU  - Chien-Cheng Lin
AU  - Thomas B. Lowe
AU  - Eugene A. Magnier
AU  - Kaisey S. Mandel
AU  - C. Tanner Murphey
AU  - Gautham Narayan
AU  - Gregory S. H. Paek
AU  - Kishore C. Patra
AU  - Haille M. L. Perkins
AU  - Armin Rest
AU  - Benjamin J. Shappee
AU  - Richard J. Wainscoat
PY  - 2026
DA  - 2026/10/06
PB  - arXiv
DO  - 10.48550/arxiv.2610.08903
UR  - https://arxiv.org/abs/2610.08903
AB  - 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±1.6, a factor of ∼2-4 higher than mass-modeling estimates. We fit the Pan-STARRS photometry with a magnetar energy-injection model including ^56Ni 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_spin=4.1^+0.7_−1.0 ms and magnetic field B_⊥=2.4^+1.1_−0.8×10^14 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 ∼575 km s^−1 and an exceptionally high Lyα escape fraction of f_esc^Lyα=0.23±0.03. 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.
ER  -