LEGGOS：宇宙正午时期五个透镜星系中N、O、Ne、S和Ar的直接丰度
LEGGOS: Direct abundances of N, O, Ne, S, and Ar in five lensed galaxies at Cosmic Noon
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中文总结 AI 辅助
利用JWST/NIRSpec数据测量五个透镜星系在宇宙正午的直接化学丰度，发现氧丰度范围及元素比值趋势，支持核坍缩超新星增丰主导。
中文摘要 AI 辅助
我们利用LEGGOS巡天的JWST/NIRSpec数据，展示了宇宙正午时期（$2.481 \leq z \leq 3.625$）五个强透镜星系的直接$T_e$化学丰度。我们在所有五个星系中测量了N、O、S和Ar的气相丰度，并在两个星系中测量了Ne。三个星系有来自多个不同电离区的电子温度约束，我们发现这些约束与在本地和高红移星系中观测到的温度标度关系大体一致。我们发现氧丰度范围为$8.04 \leq 12+\log(\text{O/H}) \leq 8.79$（太阳丰度的22%至126%）。N/O和Ne/O的比值与本地星系中观测到的趋势一致。我们在样本中未观察到N显著增强的证据，尽管样本中最年轻的星系（SGAS-J1050）的$\log(\text{N/O}) = 1.20 \pm 0.08$略有升高，我们认为这可能由一群年轻大质量恒星驱动。S/O和Ar/O的比值通常低于太阳值，与其他高红移星系中观测到的趋势相似。我们发现S/O和Ar/O丰度低于太阳值，与核坍缩超新星（CCSNe）的增丰一致。对LEGGOS星系恒星形成历史的建模支持CCSNe增丰，因为每个星系都显示出最近一段持续$\lesssim 100$ Myr的恒星形成时期，表明Ia型超新星尚没有足够时间对这些星系的气相丰度做出显著贡献。
英文摘要
We present direct $T_e$ chemical abundances in five strongly lensed galaxies at Cosmic Noon ($2.481 \leq z \leq 3.625$) using JWST/NIRSpec data from the LEGGOS survey. We measure gas-phase abundances of N, O, S, and Ar in all five galaxies, and Ne in two galaxies. Three galaxies have electron temperature constraints from multiple different ionization zones, and we find that these are broadly consistent with temperature scaling relations observed in both local and high-$z$ galaxies. We find a range of oxygen abundances $8.04 \leq 12+\log(\text{O/H}) \leq 8.79$ (22 -- 126\% $Z_{\odot}$). The ratios of N/O and Ne/O are consistent with trends observed in local galaxies. We do not observe any evidence for significant N enhancement in our sample, though the youngest galaxy in our sample (SGAS-J1050) has a mildly elevated $\log(\text{N/O}) = 1.20 \pm 0.08$, which we suggest may be driven by a population of young massive stars. The ratios of S/O and Ar/O are generally sub-solar, similar to trends observed in other high-$z$ galaxies. We find that the S/O and Ar/O abundances are sub-solar, consistent with enrichment from core-collapse supernovae (CCSNe). Modeling of the star formation histories of the LEGGOS galaxies supports CCSNe enrichment, as each galaxy shows a recent period of star formation lasting $\lesssim 100$ Myr, indicating that type Ia supernovae would not yet have had enough time to contribute significantly to the gas-phase abundances of these galaxies.
发表机构
- International Space Science Institute（国际空间科学研究所）
- University of Washington（华盛顿大学）
- University of Pittsburgh（匹兹堡大学）
- NASA Goddard Space Flight Center（美国宇航局戈达德太空飞行中心）
- University of Maryland, Baltimore County（马里兰大学巴尔的摩县分校）
- Center for Research and Exploration in Space Science and Technology（空间科学与技术研究探索中心）
- University of Michigan（密歇根大学）
- University of Cincinnati（辛辛那提大学）
- University of Arizona（亚利桑那大学）
- Eureka Scientific（尤里卡科学公司）
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