Extreme Stellar Death and Galaxy Feedback at z = 2: A Rest-frame Ultraviolet Characterization of the Strongly Lensed Superluminous Supernova 2025wny
Year: 2026
Type: preprint
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.
Source: arXiv (Cornell University)
Authors: Hoogendam, Willem B., Jones, David O., Storfer, Christopher J., Izzo, Luca, Davis, Kyle W., Kong, Miranda Y., Auchettl, Katie, Agrawal, Aadya, Aguilera-Dena, David R., Chambers, Kenneth C., Chen, Siyuan, de Boer, Thomas, Foley, Ryan J., Grayling, Matthew, Hinkle, Jason T., Hjorth, Jens, Huber, Mark E., Lin, Chien-Cheng, Lowe, Thomas B., Magnier, Eugene A., Mandel, Kaisey S., Murphey, C. Tanner, Narayan, Gautham, Paek, Gregory S. H., Patra, Kishore C., Perkins, Haille M. L., Rest, Armin, Shappee, Benjamin J., Wainscoat, Richard J.
Institutions: University of Hawaiʻi at Mānoa, University of Hawaii System, University of Hawaii at Hilo, University of Copenhagen, Astronomical Observatory of Capodimonte, National Institute for Astrophysics, University of California, Santa Cruz, The University of Melbourne, University of Illinois Urbana-Champaign, Universidad Nacional Autónoma de México, Center for Astrophysics Harvard & Smithsonian, Institute of Astronomy, NSF-Simons AI Institute for the Sky, National Center for Supercomputing Applications, Space Telescope Science Institute, Johns Hopkins University, University of Cambridge
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, W. M. Keck Foundation, Research Corporation for Science Advancement, University of California, Santa Cruz, California Institute of Technology, Villum Fonden, Space Telescope Science Institute, NASA Exoplanet Science Institute, European Commission, University of Illinois at Urbana-Champaign
Awards: G1700342535, NEO DISCOVERY AND CHARACTERIZATION WITH THE PAN-STARRS PS1 TELESCOPE. WE WILL USE THE PAN-STARRS PS1 TELESCOPE SYSTEM TO RAPIDLY SURVEY LARGE AREAS O, G253522920, G3161924517, NSF-Simons AI Institute for the Sky (SkAI Institute), Cosmology in the Local Volume with Hawai'i Supernova Flows, G4084488544, HEROIC - Hop Enabled Realtime Observatory Information and Coordination, G433322167, G440604560, G4446457410, Frameworks: SCiMMA: Real-time Orchestration of Multi-Messenger Astrophysical Observations, Graduate Research Fellowship Program (GRFP), THE POWER OF THE PAN-STARRS1 TELESCOPE TO DISCOVER NEOS HAS BEEN AMPLY DEMONSTRATED WITH THE CURRENT 11% DEDICATED ALLOCATION OF OBSERVING TIME SUPPO, EPSCoR Research Fellows: NSF: Building a Duke University and University of Hawaii Collaboration for the Next Decade of Supernova Cosmology, Collaborative Research: The Connection between Astrophysical Transients and their Host Galaxies Across Cosmic Time, G58316358, G618131832, G6273510985, G6303308287, A NEO SEARCH PROGRAM USING THE PAN-STARRS PS1 TELESCOPETHE GOAL OF THE PROPOSED RESEARCH IS TO USE T, G7265250500, G7339468730, CAREER: Understanding the Nature of Dark Energy with the Young Supernova Experiment and the Legacy Survey of Space and Time, G8380168758, THE OBJECTIVE OF THIS PROPOSAL IS TO SIGNIFICANTLY UPGRADE THE PAN-STARRS TELESCOPE SYSTEM ON HALEAKALA, MAUI BY COMPLETING THE INSTRUMENTATION AND C, G9000928711, WE PROPOSE TO CONTINUE OUR SURVEY TO DISCOVER NEAR EARTH OBJECTS (NEOS) WITH THE PAN-STARRS SYSTEM EXPANDED TO INCLUDE THE PAN-STARRS2 OBSERVATORY (PS2) TOGETHER WITH THE PAN-STARRS1 OBSERVATORY (PS1). SINCE THE START OF DEDICATED USE OF PAN- STARRS FOR NEO DISCOVERY IN SPRING OF 2014 PS1 HAS DISCOVERED OVER 40% OF ALL NEOS AND OVER 50% OF THE LARGER NEOS AND POTENTIALLY HAZARDOUS ASTEROIDS. PS1 IS ALSO THE LEADING DISCOVERY TELESCOPE FOR NEOS LARGER THAN 1 KM IN DIAMETER. WITH PS2 WE WILL AT LEAST DOUBLE OUR RAW SURVEY POWER. THE PAN-STARRS2 OBSERVATORY IS COMPLETE AND WE EXPECT TO COMPLETE ITS CAMERA (GPC2) SOON AND ADD SCIENCE OPERATIONS WITH PS2 TO THE ONGOING PS1 SURVEY. PS2 WILL BE IN FULL SCIENCE OPERATIONS BY THE START OF THE PERIOD OF PERFORMANCE OF THIS PROPOSAL. THE PS2 OPTICS ARE SUPERIOR TO THOSE OF PS1 AND WE HAVE ELIMINATED THE CAUSE OF CORRELATED READ NOISE THAT AFFLICTS FAINT OBJECTS IN THE CAMERA ON PS1. THUS WE EXPECT PS2 TO BE SLIGHTLY SUPERIOR TO PS1 IN DISCOVERING NEOS. THE PAN-STARRS SYSTEM WITH BOTH PS1 AND PS2 WILL CHANGE THE LANDSCAPE OF NEO DISCOVERY. WE CAN DOUBLE THE AREA SURVEYED OR PERFORM SELF FOLLOW-UP OBSERVATIONS WHICH WILL SIGNIFICANTLY DECREASE THE NUMBER OF OBJECTS LOST DUE TO AN ABSENCE OF FOLLOW-UP. MORE SELF-FOLLOW-UP WILL ALSO AVOID BIASES INTRODUCED BY THE DIGEST SCORE AND PROVIDE A MORE SYSTEMATIC SURVEY. WE WILL INVESTIGATE WIDE AREA SURVEY STRATEGIES RANGING BETWEEN THESE TWO EXTREMES TO OPTIMIZE FOR THE MOST COMPLETE NEO SURVEY AND TO REDUCE LOSSES OF RARE OR CAMOUFLAGED NEOS THAT WE ARE CURRENTLY UNDER-SAMPLING. IN ADDITION TO BRINGING THE SURVEY POWER OF PS2 ON LINE WE HAVE IDENTIFIED PROMISING AVENUES WHERE WE CAN IMPROVE OUR DISCOVERY RATE BY ADVANCES IN SOFTWARE INCLUDING IMPROVED DE-TRENDING ASTROMETRY OBJECT DETECTION IMAGE SUBTRACTION AND MACHINE LEARNING TECHNIQUES. FINALLY WE HAVE AN EXPERIENCED TEAM WITH A PROVEN RECORD OF SUCCESS., G973579988
OpenAlex ID: W7220948019