发表机构
INAF, Osservatorio Astronomico di Capodimonte; University of California, Santa Cruz; The University of Melbourne（意大利国家天体物理研究所卡波迪蒙特天文观测台; 加州大学圣克鲁兹分校; 墨尔本大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过强透镜SLSN 2025wny的紫外光谱与光变曲线拟合，揭示其磁星参数与低红移一致，并发现高速外流和高Lyα逃逸，为早期宇宙恒星死亡与星系反馈提供新证据。
AI 中文摘要
我们展示了强透镜、贫氢超亮超新星（SLSN）2025wny（红移$z = 2.0155$）的光度和光谱后续观测。我们使用凯克II/KCWI积分场光谱获得了最大光后11至61天的静止系紫外光谱。我们利用Pan-STARRS测光约束最亮像的放大率，得到$\mu_A=19.4\pm1.6$，比质量模型估计值高约2-4倍。我们使用瞬变源模块化开源拟合器（MOSFiT）将Pan-STARRS测光数据与包含$^{56}$Ni衰变的磁星能量注入模型进行拟合；该模型能够以局域宇宙SLSNe-I的典型参数再现接近最大光的光变曲线，包括磁星自转周期$P_{\rm spin}=4.1^{+0.7}_{-1.0}\\,\mathrm{ms}$和磁场$B_{\perp}=2.4^{+1.1}_{-0.8}\times10^{14}\\,\mathrm{G}$；然而，晚期平台表明存在额外的能源。在光谱上，静止系紫外光谱中几乎不存在铁族元素谱线遮蔽，吸收特征与先前通过丰度层析识别出的SLSN-I特征相符。根据窄星际介质谱线金属丰度估计，SN 2025wny爆发于一个亚太阳金属丰度星系中。从我们静止系紫外到光学光谱中的宿主星系谱线，我们估计高速外流速度约为$\sim575$ km s$^{-1}$，且Ly$\alpha$逃逸分数极高，为$f_{esc}^{Ly\alpha}=0.23\pm0.03$。SN 2025wny与较低红移的SLSNe相当吻合。即将开展的LSST和Roman等巡天项目将发现更多高红移SLSNe，进一步检验SLSNe-I爆炸在早期宇宙中是否在群体层面上保持一致。
英文摘要
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.
Comments27 pages, 17 figures. To be submitted to AAS Journals
