CECILIA：宇宙正午低电离气体过量星云发射的多线约束
CECILIA: Multi-line Constraints on Excess Nebular Emission from Low-Ionization Gas at Cosmic Noon
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中文总结 AI 辅助
本研究利用CECILIA巡天的19个星系JWST/NIRSpec光谱，分析[O I]和[S II]发射，发现约半数过量发射无法由常规HII区模型解释，可能源于HII区外的弥散电离气体，并指出对硫丰度测量的微小偏差。
中文摘要 AI 辅助
来自JWST的光谱学为宇宙正午（z~2-3）的元素丰度模式提供了独特见解，最显著的是亚太阳S/O的日益增长的统计。这些新测量，加上z>1处[O I]λ6302的新观测，推动了对宇宙正午星系内中性及低电离发射的更新研究。在本信中，我们利用CECILIA巡天中通过超深JWST/NIRSpec光谱观测的19个星系，提出了对[O I]λ6302和[S II]λλ6718,33的新分析。我们发现，在分析S2-BPT上的星系时，有必要考虑高红移下硫的亚太阳丰度模式，并且这一修正揭示了CECILIA星系中额外发射源的潜力。使用光致电离模型模拟器Cue，我们发现CECILIA星系中约48%的观测[S II]发射和约55%的观测[O I]发射无法由常规HII区模型重现。与现有模型比较时，我们未发现湍流或激波驱动这种过量发射的明确证据。我们的发现表明，这种过量发射可能起源于HII区之外的弥散电离气体，但其性质可能不同于低红移的弥散电离气体（DIG）。此外，我们发现包括恒星形成区之外的气体发射可能会在12+log(S/H)中引入高达0.1 dex的小偏差。
英文摘要
Spectroscopy from JWST has offered unique insights into elemental abundance patterns at Cosmic Noon (z~2-3), most notably a growing census of sub-solar S/O. These new measurements, coupled with new observations of [O I]λ6302 at z>1, motivate an updated study of neutral and low-ionization emission within Cosmic Noon galaxies. In this letter, we present a new analysis of [O I]λ6302 and [S II]λλ6718,33 in 19 galaxies observed using ultra-deep JWST/NIRSpec spectroscopy as part of the CECILIA survey. We find that it is necessary to consider sub-solar abundance patterns in sulfur at high-z when analyzing galaxies on the S2-BPT, and that this correction reveals the potential of additional emission sources in CECILIA galaxies. Using the photoionization model emulator Cue, we find that ~48% of observed [S II] and ~55% of observed [O I] emission in CECILIA galaxies cannot be reproduced by conventional HII region models. We find no clear evidence for turbulence or shocks driving this excess emission when comparing to existing models. Our findings imply that this excess emission may originate in diffuse ionized gas outside of H II regions, though its nature may be different than that of low-z DIG. Further, we find that including emission from gas outside of star-forming regions can incur a small bias up to 0.1 dex in 12+log(S/H).
发表机构
- Northwestern University（西北大学）
- Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA)（天体物理跨学科探索与研究中心）
机构由 AI 辅助整理，请以论文原文为准。
