AI 中文总结
研究极贫金属星系HSCJ1631+4426和SDSSJ0811+4730，利用积分场光谱观测获取数据，得出其氧丰度和Fe/O比，发现极低金属丰度下铁元素异常增强，可能由罕见高能爆炸导致，证明XMPs可反映早期恒星爆炸核合成过程。
AI 中文摘要
我们展示了对两个本地极贫金属星系（XMPs）HSCJ1631+4426和SDSSJ0811+4730的积分场光谱观测。使用凯克宇宙网成像仪（KCWI）在3545-5529 Å波长范围内、光谱采样为0.5 Å获取数据，捕捉用于确定气相金属丰度和化学富集测量的明亮星云发射线。通过积分光谱得出了两个星系的氧丰度和Fe/O比。这些测量表明在极低金属丰度下铁元素有异常高效的增强，Fe/O比接近或超过太阳，与仅由核心坍缩超新星或延迟Ia型超新星的富集情况不符。与化学演化模型比较表明，可能是罕见的高能爆炸如明亮的超新星和/或对不稳定超新星造成的。我们的结果进一步证明XMPs可反映早期高能恒星爆炸的核合成过程，是早期宇宙中普遍存在的化学富集途径的本地实验室。
英文摘要
We present integral field spectroscopic observations of two local extremely metal-poor galaxies (XMPs), HSCJ1631+4426 and SDSSJ0811+4730, obtained with the Keck Cosmic Web Imager (KCWI) over the wavelength range $3545-5529$ Å at a spectral sampling of 0.5 Å, capturing bright nebular emission lines essential for determining gas-phase metallicity and chemical enrichment measurements. Using integrated spectra, we derive oxygen abundances of $\rm12+\log(O/H)=7.079\pm0.010$ and $6.926\pm0.004$, and elevated Fe/O ratios of $\rm\log(Fe/O)=-1.57\pm0.17$ and $-1.28\pm0.07$, for HSCJ1631+4426 and SDSSJ0811+4730 respectively. Each galaxy is fully contained within the $\sim$8'' field of view, with 0.15'' spaxels providing spatially resolved information. These measurements indicate unusually efficient iron enhancement at extremely low metallicity; Fe/O ratios approach or exceed solar despite oxygen abundances of only $\sim$2% solar, inconsistent with enrichment from core-collapse supernovae alone or delayed Type Ia supernovae given the young ages of the systems. Comparison with chemical evolution models suggests rare, highly energetic explosions such as bright hypernovae and/or pair-instability supernovae are likely responsible. Our results reinforce the growing evidence that XMPs can reflect the nucleosynthetic processes of early energetic stellar explosions, serving as local laboratories for chemical enrichment pathways prevalent in the early Universe.
