SN 2025wny IV后续研究：强引力透镜超亮超新星的测光时间延迟测量
Follow-up of SN 2025wny IV: Photometric Time-delay Measurements of a Strongly Lensed Superluminous Supernova
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中文总结 AI 辅助
本研究对首个强引力透镜SLSN-I SN 2025wny进行测光时间延迟测量，采用GausSN建模，测得时间延迟并结合透镜模型得到H₀，验证了强引力透镜超新星作为H₀独立探针的潜力。
中文摘要 AI 辅助
我们公布了SN 2025wny的测光时间延迟测量结果，SN 2025wny是首个被发现的红移z=2.015的强引力透镜I型超亮超新星（SLSN-I）。强引力透镜超新星的时间延迟测量可作为独立的宇宙学探针，用于测量哈勃常数H₀，且无需依赖本地距离阶梯。我们利用多设备成像数据，通过场景建模测光法分离出4个透镜像（A-D）并构建了grizJ波段的光变曲线；采用GausSN（Hayes等人2024年提出）的高斯过程回归对已解析的光变曲线进行建模，以推断透镜像之间的相对时间延迟和放大率。研究发现恒定放大率模型对数据的描述效果欠佳，因此提出了随时间变化的S型放大率模型，以解释像A相对放大率的演化。我们测得时间延迟Δt_AB = -10.6⁺².²₋₂.⁵天、Δt_AC = 1.2⁺².⁷₋₂.⁶天（68%可信区间），与Johansson等人（2026年）的独立光谱测量结果一致。将测光时间延迟与Mörtsell等人（2026年）的透镜模型结合，得到H₀,photo = 80.5⁺²⁶.⁴₋₁₆.⁷ km·s⁻¹·Mpc⁻¹；若同时纳入光谱时间延迟，则得到H₀,comb = 70.8⁺⁸.²₋₆.¹ km·s⁻¹·Mpc⁻¹。我们的结果进一步证明了强引力透镜超新星作为H₀独立探针的潜力。
英文摘要
We present photometric time-delay measurements of SN 2025wny, the first strongly lensed Type I superluminous supernova (SLSN-I), discovered at $z = 2.015$. Time-delay measurements from strongly lensed supernovae provide an independent probe of cosmology and the Hubble constant, $H_0$, without reliance on the local distance ladder. Using multi-facility imaging data, we performed scene-modelling photometry to deblend four of the lensed images (A-D) and construct $grizJ$-band light curves. We modelled the resolved light curves with Gaussian process regression using GausSN (Hayes et al. 2024) to infer relative time delays and magnifications between the lensed images. We found that a constant magnification model provides a suboptimal description of the data, motivating a time-dependent sigmoid magnification model to account for evolving relative magnification of image A. We measured time delays of $Δt_{AB} = -10.6^{+2.2}_{-2.5}$ days and $Δt_{AC} = 1.2^{+2.7}_{-2.6}$ days (68% credible intervals), consistent with independent spectroscopic measurements from Johansson et al. (2026). Combining the photometric time delays with the lens model of Mörtsell et al. (2026) gives $H_{0,\:\rm photo} = 80.5^{+26.4}_{-16.7}\;\rm km\,s^{-1}\,Mpc^{-1}$, while including the spectroscopic time delays as well yields $H_{0,\:\rm comb} = 70.8^{+8.2}_{-6.1}\;{\rm km\,s^{-1}\,Mpc^{-1}}$. Our results further demonstrate the potential of strongly lensed supernovae as independent probes of $H_0$.
