发表机构
University of Vienna; Max-Planck Institute for Astronomy; Universität Heidelberg; National Radio Astronomy Observatory; Deutsches Zentrum for Astrophysics; Stanford University; Jet Propulsion Laboratory, California Institute of Technology（维也纳大学; 马克斯·普朗克天文学研究所; 海德堡大学; 美国国家射电天文台; 德国天体物理中心; 斯坦福大学; 加州理工学院喷气推进实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
NeAtHood项目I结合单天线与干涉式HI观测，解析扩展猎户座星云的中性氢气体，发现其膨胀壳质量低于[CII]观测结果，还揭示了次级泡等新结构，为研究恒星形成区多相结构提供了新视角。
AI 中文摘要
猎户座星云是距离最近的正在进行及近期完成的大质量恒星形成区域，是研究大质量恒星输入的质量、能量与动量的独特实验室。我们呈现21厘米发射线观测结果，首次以1角分的分辨率解析了扩展猎户座星云（EON）中的中性原子氢（HI）气体，该分辨率对应该区域标准距离下0.12秒差距的物理尺度。我们的HI发射图揭示出一个膨胀壳，其与近期电离碳（[CII]）线发射观测划定的EON轮廓相匹配。然而，我们结合单天线与干涉式HI观测的结果显示，该壳前半球的物质质量为100倍太阳质量，比从[CII]观测推断出的质量低约一个数量级。这一差异表明，最近的风泡质量被高估了，尽管我们不排除壳中存在大量分子氢（H₂）可能解释部分差异的可能性。我们的扩展21厘米线图还揭示了EON内部及周边未被发现的结构，包括一个可能的次级泡和一条从壳边界延伸约4秒差距的线性突出结构。我们的结果表明，HI干涉观测有望阐明恒星形成区多相结构及其与周围环境关联的关键方面。
英文摘要
The Orion Nebula is the nearest site of ongoing and recent high-mass star formation. It is a unique laboratory for studying the mass, energy, and momentum input from high-mass stars. We present 21-centimeter emission line observations that resolve for the first time the neutral atomic hydrogen (HI) gas in the extended Orion nebula (EON) at a resolution of one arcminute, which corresponds to a physical scale of 0.12 parsecs at the standard distance to the region. Our HI emission maps reveal an expanding shell that matches the EON contours delineated by recent observations of ionized carbon ([CII]) line emission. However, our combination of single-dish and interferometric HI observations suggests 100 solar masses of material for the front hemisphere of the shell, which is lower by roughly a factor of ten than the mass inferred from [CII] observations. This discrepancy suggests that the mass of the nearest wind-blown bubble has been overestimated, although we do not rule out the possibility that a significant amount of molecular hydrogen (H_2) in the shell may account for part of the difference. Our extended 21 cm line maps also reveal uncharted structures in and around the EON. They include a probable secondary bubble and a linear protrusion extending roughly four parsecs from the shell boundary. Our results illustrate the potential of HI interferometric observations to elucidate key aspects of the multiphase structure of star-forming regions and their connection to their surroundings.
Comments16 pages, 19 figures
Journal refA&A, 711, A85 (2026)
DOI：10.1051/0004-6361/202659272
