鲁宾 commissioning 数据中的 AT2025agpz：区分致密星系中的明亮相互作用超新星与核暂现源
AT2025agpz in Rubin commissioning data: distinguishing a luminous interacting supernova from nuclear transients in compact galaxies
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中文总结 AI 辅助
本研究在鲁宾 commissioning 数据中发现暂现源 AT2025agpz，通过其特征区分出它是明亮相互作用超新星而非核暂现源，凸显鲁宾时代暂现源分类的挑战与机遇。
中文摘要 AI 辅助
Vera C. 鲁宾天文台的时空遗产巡天将发现数量空前的稀有、长寿命光学暂现源，其中许多因过暗或数量过多而无法进行全面的光谱后续观测。因此，表征介于已确认暂现源类别边界的天体对于改进测光分类至关重要。我们报告 AT2025agpz，这是一个红移 z=0.147 的明亮暂现源，由 ATLAS 在峰值附近发现，并在鲁宾对欧几里得南天深场的 commissioning 观测中得到广泛监测。该暂现源与一个暗淡矮星系的核重合，其静止帧上升时间为 77.9±1.3 天，峰值热光度达 6.3×10^43 erg s^-1。鲁宾 commissioning 数据的卓越深度和采样频率，结合互补的 DECam 成像，严格限制了爆发历元，并得出早期幂律上升指数 n=3.33^+0.33_-0.28。后续光谱观测显示其光谱演化极慢，以窄巴尔末发射线为主，而高分辨率 X-shooter 观测则分辨出宽电子散射翼和多个 Hα 发射成分，这是相互作用驱动超新星的特征。光谱能量分布建模表明其宿主星系质量低、中等恒星形成。尽管 AT2025agpz 占据了最近确认的“模糊核暂现源”群体的观测参数空间，但其颜色演化、宿主环境和发射线形态更倾向于相互作用驱动的明亮超新星。更广泛而言，该事件凸显了明亮相互作用超新星与核暂现源之间日益增长的观测重叠，阐明了鲁宾时代暂现源分类面临的挑战与机遇。
英文摘要
The Vera C. Rubin Observatory's Legacy Survey of Space and Time will discover unprecedented numbers of rare, long-lived optical transients, many of which will be too faint or too numerous for comprehensive spectroscopic follow-up. Characterising objects that span the boundaries between established transient classes is therefore essential for improving photometric classification. We present AT2025agpz, a luminous transient at $z=0.147$, discovered around peak by ATLAS but extensively monitored during Rubin commissioning observations of the Euclid Deep Field South. The transient is coincident with the nucleus of a faint dwarf galaxy, exhibits a rest-frame rise time of $77.9\pm1.3$ d, and reaches a peak bolometric luminosity of $6.3\times10^{43}$ erg s$^{-1}$. The exceptional depth and cadence of the Rubin commissioning data, combined with complementary DECam imaging, tightly constrain the explosion epoch and yield an early-time power-law rise of $n=3.33^{+0.33}_{-0.28}$. Follow-up spectroscopy reveals remarkably slow spectral evolution dominated by narrow Balmer emission, while high-resolution X-shooter observations resolve broad electron-scattering wings and multiple H$α$ emission components characteristic of interaction-powered supernovae. Spectral energy distribution modelling indicates a low-mass, moderately star-forming host galaxy. Although AT2025agpz occupies observational parameter space shared by the recently identified Ambiguous Nuclear Transient population, its colour evolution, host environment, and emission-line morphology favour an interaction-powered luminous supernova. More broadly, this event highlights the growing observational overlap between luminous interacting supernovae and nuclear transients, illustrating both the challenges and opportunities for transient classification in the Rubin era.
