AI 中文总结
JWST在近侧星系NGC 3310中发现的Ia-CSM超新星2026sqf，其爆炸前探测到疑似富碳AGB前身系统，为研究Ia-CSM超新星起源提供了近距样本。
AI 中文摘要
超新星（SN）2026sqf近期出现在近侧面向旋涡星系NGC 3310中，已显示出与星周介质（CSM）强烈相互作用的迹象。这种在近侧超新星中罕见的强烈相互作用，为揭示其前身系统的起源和性质提供了宝贵机会。我们分析了SN 2026sqf的早期光谱和光变曲线（LCs），观测光谱的总体形状、发射线强度以及光变曲线演化均表明，SN 2026sqf属于罕见的Ia-CSM超新星子类。若得到证实，它将是该类中已知距离最近的成员，距离D~19 Mpc。我们还报告了JWST爆炸前成像中识别出的首个热核超新星前身系统候选体，以及首个爆炸白矮星（WD）的（可能）富碳AGB供体的证据。我们的结果与Ia-CSM超新星源自由白矮星和经历共包层阶段的AGB星组成的系统的预期一致。CSM质量和尘埃含量与AGB环境的预期相符，但窄线宽超过超风膨胀速度，支持 episodic ejection（ episodic ejection 保留原表述）。爆炸前不久的双星相互作用是自然解释，不过该通道和时标仍不确定。后续的晚期观测，尤其是使用JWST开展的观测，将验证我们对早期阶段的识别和结论。
英文摘要
Supernova (SN) 2026sqf recently appeared in the nearby face-on spiral galaxy NGC 3310 and has shown signs of strong interaction with a circumstellar medium (CSM). Such intense interaction, rare among nearby SNe, offers a valuable opportunity to reveal details on the origin and nature of its progenitor system. We analyzed the early-phase spectra and light curves (LCs) of SN 2026sqf. The general shapes of the observed spectra, the strengths of the emission lines, and the LC evolution all suggest that SN 2026sqf belongs to the rare SN Ia-CSM subclass. If confirmed, this would be the closest known member of this class, at D~19 Mpc. We also report the first candidate progenitor system for a thermonuclear supernova identified in JWST pre-explosion imaging, and the first evidence for a (probable) carbon-rich AGB donor to the exploding white dwarf (WD). Our results are consistent with the expectation that SNe Ia-CSM emerge from a system consisting of a WD and an AGB star undergoing a common-envelope phase. The CSM mass and dust content are consistent with expectations for an AGB environment, but the narrow-line width exceeds superwind expansion velocities, favoring an episodic ejection. Binary interaction shortly before the explosion is a natural explanation, though the channel and timescale remain uncertain. Late-time follow-up, especially with JWST, will test the identification and the conclusions of our early-phase analysis.
Comments10 pages, 9 figures, 3 tables; submitted to A&A (as a Letter)
