发表机构
Xinjiang Astronomical Observatory, Chinese Academy of Sciences; School of Astronomy and Space Science, University of Chinese Academy of Sciences; Physics Department, Tsinghua University; National Astronomical Observatories, Chinese Academy of Sciences; Center for Astronomy and Space Sciences, China Three Gorges University; College of Mathematics and Physics, China Three Gorges University; School of Physical Science and Technology, Xinjiang University; Las Cumbres Observatory（中国科学院新疆天文台; 中国科学院大学天文与空间科学学院; 清华大学物理系; 中国科学院国家天文台; 三峡大学天文与空间科学中心; 三峡大学数学与物理学学院; 新疆大学物理科学与技术学院; 拉斯坎布雷天文台）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文对Ia型超新星SN 2021pfs开展多波段观测，发现其与SN 2011fe极为相似但存在短波长测光差异，推测其前身星金属丰度更高，该差异或影响距离估计，需更多同类样本验证。
AI 中文摘要
我们呈现了对正常Ia型超新星（SNe Ia）2021pfs的广泛测光和光谱观测结果，该超新星位于红移0.009的赛弗特2型星系NGC 5427中。SN 2021pfs达到的绝对B波段峰值星等为$M_{\rm max}(B)=$-19.28±0.40 mag，峰值后下降率$\triangle m_{15}(B)=$1.13±0.06 mag。这颗近邻Ia型超新星的观测特性与SN 2011fe极为相似，包括主要光学光谱特征和测光演化。尽管它们的下降率相似，但在极早期阶段，SN 2021pfs在U波段的上升速度比SN 2011fe更快，而在r和i波段则更慢。这种测光差异，尤其是在短波长处，会给距离估计带来高达约12%的系统不确定性。对宿主星系局部和全局环境的分析显示，该环境表明SN 2021pfs的前身星金属丰度高于SN 2011fe。更高的前身星金属丰度或许可以解释观测到的测光差异以及SN 2021pfs与SN 2011fe之间的距离，不过需要更大的此类“双胞胎”Ia型超新星样本，以确认这一趋势并评估其对宇宙学测量的影响。
英文摘要
We present extensive photometric and spectroscopic observations of the normal type Ia supernovae (SNe Ia) 2021pfs, which occurred in the Seyfert 2 galaxy NGC 5427 at a redshift 0.009. SN 2021pfs reached an absolute \textit{B}-band peak magnitude of $M_{\rm max}(B)=$-19.28 $\pm$ 0.40 mag. The mag and a post-peak decline rate of $Δm_{15}(B)=$1.13 $\pm$ 0.06 mag. The observed properties of this nearby SN Ia closely resemble those of SN 2011fe, including the main optical spectroscopic features and photometric evolution. Despite their similar decline rates, SN 2021pfs rose more rapidly in the $U$ band but more slowly in the $r$ and $i$ bands compared to SN 2011fe in very early phases. This photometric difference, particularly at short wavelengths, can introduce a systematic uncertainty of up to $\sim$12% in distance estimates. Analysis of the host galaxy's local and global environment shows an environment consistent with producing a higher-metallicity progenitor for SN 2021pfs than that of SN 2011fe.This higher progenitor metallicity may explain the observed photometric discrepancy and the resulting distance between SN 2021pfs and SN 2011fe, though a larger sample of such "twin" SNe Ia is needed to confirm this trend and assess its impact on cosmological measurements.
Comments35 pages, 14 figures, published in SCIENCE CHINA Physics, Mechanics & Astronomy,DOI: 10.1007/s11433-026-2999-3
Journal refScience China Physics, Mechanics & Astronomy, 2026, Volume 69, Issue 9, id.299511
